blob: 86448a37077f0cd780d810df0c8c1ba3107cb259 [file] [log] [blame]
C-Kermit 8.0 Unix Installation Instructions
[ [1]Contents ] [ [2]C-Kermit ] [ [3]Kermit Home ]
Frank da Cruz
The Kermit Project
Columbia University
As of C-Kermit version: 8.0.211, 10 April 2004
This file last updated: Tue Apr 13 10:14:33 2004 (New York City
IF YOU ARE READING A PLAIN-TEXT version of this document, note that
this file is a plain-text dump of a Web page. You can visit the
original (and possibly more up-to-date) Web page here:
[ [23]Top ] [ [24]Contents ] [ [25]Next ]
WARNING: This document contains notes that have been accumulating
since the early 1980s. Many of the products and Unix versions
mentioned here have not been heard of in a long while, but that
does not necessarily mean they are not still running in some
obscure nook.
This file contains Unix-specific information. A lot of it. Unlike most
other packages, C-Kermit tries very hard to be portable to every Unix
variety (and every release of each one) known to exist, including many
that are quite old, as well as to other platforms like VMS, AOS/VS,
VOS, OS-9, the BeBox, the Amiga, etc.
Since C-Kermit gets so deeply into the file system, i/o system, and
other areas that differ radically from one Unix platform to the next,
this means that a lot can go wrong when you try to install C-Kermit on
(for example) a new release of a particular variety of Unix, in which
certain things might have changed that C-Kermit depended upon.
This file concentrates on installation. For a description of general
configuration options for C-Kermit, please read the [26]Configurations
Options document. For troubleshooting after installation, see the
[27]General Hints and Tips and [28]Unix-Specific Hints and Tips
documents. The latter, in particular, contains lots of information on
lots of specific Unix platforms. If you want to work on the source
code, see the [29]C-Kermit Program Logic Manual
You may install C-Kermit:
* From an "[30]install package", if one is available.
* As a [31]prebuilt binary, if available, plus accompanying text
* By building from [32]source code.
[ [33]Top ] [ [34]Contents ] [ [35]Next ] [ [36]Previous ]
If your Unix computer is on the Internet and it has a C compiler,
here's how to download, build, and install C-Kermit directly from the
"tarballs" or Zip archives:
1. Make a fresh directory and cd to it.
2. Download the C-Kermit source code:
(compress format) or
(gunzip format).
3. Uncompress the compressed tar file with "uncompress" or "gunzip",
according to which type of compressed file you downloaded. (If you
don't understand this, you could download a (much larger)
uncompressed tar archive directly:
4. Now type "tar xvf cku211.tar" to unpack the individual files from
the tar archive.
5. Type "rm cku211.tar" to get rid of the tar archive, which is no
longer needed.
6. Read the comments at the top of the makefile to find out which
target to use and then type the appropriate "make" command, such
as "make linux", "make solaris8", etc.
7. This produces a binary in your current directory called "wermit".
Start it by typing "./wermit" and [40]try it out to make sure it
works. Then read [41]Section 5 for how to install it, or simply
copy the wermit binary to the desired public directory, rename it
to kermit, and give it the needed permissions (and, if it is going
to be used to dial out, give it the same group and owner and
permissions as the cu, tip, or minicom program).
For secure installations, see [42]Sections 5 and [43]16.
[ [44]Top ] [ [45]Contents ] [ [46]Next ] [ [47]Previous ]
Various Unix varieties -- Linux, Solaris, AIX, etc -- now incorporate
the idea of "install packages", and many users expect to find all new
applications in this format. A selection of install packages might be
available for any given release of C-Kermit, but there is a tradeoff
between convenience and safety. Unix presents several notable problems
to the builder of install packages:
a. Since C-Kermit is portable to many non-Unix platforms (VMS, VOS,
AOS/VS, etc), some of the files in the C-Kermit distribution do
not fit into the Unix application model. In particular, C-Kermit
includes some plain text files (described in [48]Section 5) and
Unix has no standard place to put such files. Typical Unix package
managers do not allow for them. Where should they go, and how will
the user know where to find them?
b. Installation of any program that will be used to make modem calls
requires some important decisions from the installer regarding
security and privilege.
Item (b) is discussed at length in [49]Sections 10 and [50]11 of this
document, but the package-related aspects are also given here. The
basic problem is that Unix dialout devices and the UUCP "lock files"
that regulate contention for them (described in [51]Section 10) are
usually protected against "world". Therefore, the install procedure
must either run as root in order to give the Kermit binary the
required permissions, group, and/or owner, or else the dialout devices
and associated directories must be open for group or world reading and
writing. Otherwise, the Kermit program just installed WILL NOT WORK
for dialing out.
Thus, a well-crafted installation procedure should present the options
and allow the installer to choose the method, if any, for regulating
access to the dialout devices:
a. Check the permissions of the lockfile directory and the dialout
devices. If they do not allow group or world R/W access, then:
b. "Your UUCP lockfile directory and/or dialout devices require
privilege to access. You must either change their permissions or
install Kermit with privileges."
c. "If you wish to install Kermit with privileges, it will be given
the same owner, group, and permissions as the cu program so it can
use the dialout devices."
d. If they choose (c) but the user is not root, give a message that
the install procedure can be run only by root and then quit.
It should go without saying, of course, that any binaries that are to
be included in an install package should be built fresh on the exact
platform (e.g. Red Hat 8.0 on Intel) for which the package is
targeted; prebuilt binaries ([52]next section) from other sites are
likely to have library mismatches. [53]CLICK HERE for more about
building C-Kermit install packages.
The Kermit Project does not have the resources or the expertise to
make install packages for every platform. Most install packages,
therefore, are contributed by others, and they do not necessarily
follow the guidelines given above. Pay attention to what they do.
If you are an end user who has obtained a C-Kermit install package for
a particular platform, you should be aware that some additional steps
might needed if you want to use Kermit to dial out. Read [54]Section
10 for details.
[ [55]Top ] [ [56]Contents ] [ [57]Next ] [ [58]Previous ]
Hundreds of prebuilt C-Kermit binaries are available on the CDROM in
the BINARY tree [NOTE: The C-Kermit CDROM is still for version 7.0],
and at our ftp site in the [59]kermit/bin area (with names starting
with "ck"), also accessible on the [60]C-Kermit website. To install a
prebuilt binary:
a. Rename the binary to "wermit".
b. Make sure it works; some tests are suggested in [61]Section 7.
c. Follow steps (b) through (e) in [62]Section 4.
d. Install related files as described in [63]Section 5.
But first... Please heed the following cautions:
a. If you pick the wrong binary, it won't work (or worse).
b. Even when you pick the appropriate binary, it still might not work
due to shared-library mismatches, etc. (see [64]Section 4.0).
c. Don't expect a binary built on or for version n of your OS to work
on version n - x (where x > 0). However, it is usually safe to run
a binary built on (or for) an older OS release on a newer one.
Therefore, it is better to build your own binary from source code
([65]next section) if you can. But since it is increasingly for Unix
systems (not to mention VMS and other OS's) to be delivered without C
compilers, it is often impractical. In such cases, try the most
appropriate prebuilt binary or binaries, and if none of them work,
[66]contact us and we'll see what we can do to help.
[ [67]Top ] [ [68]Contents ] [ [69]Next ] [ [70]Previous ]
Also see: [71]Section 8 and [72]Section 9.
C-Kermit is designed to be built and used on as many platforms as
possible: Unix and non-Unix, old and new (and ancient), ANSI C and
K&R. The Unix version does not use or depend on any external tools for
building except the "make" utility, the C compiler, and the linker. It
does not use any automated configuration tools such as configure,
autoconf, automake, libtool, etc. Everything in C-Kermit has been
built by hand based on direct experience or reports or contributions
from users of each platform.
The [73]C-Kermit makefile contains the rules for building the program
for each of the hundreds of different kinds of Unix systems that
C-Kermit attempts to support. It covers all Unix variations since
about 1980 -- pretty much everything after Unix V6. Separate makefiles
are used for [74]Plan 9 and [75]2.x BSD.
* The C compiler, linker, and make program must be installed.
* The C libraries and header files must be installed (*).
* The C-Kermit source code and makefile in your current directory.
* The C-Kermit text files ([76]Section 5) in your current directory.
* This is becoming problematic in this new age of "selective
installs" e.g. of Linux packages. C-Kermit builds will often fail
because replying "no" to some obscure Linux installation option
will result in missing libraries or header files. Ditto on
platforms like AIX and Solaris that don't come with C compilers,
and then later have gcc installed, but are still missing crucial
libraries, like libm (math).
* For TCP/IP networking support, the sockets library and related
header files must be installed.
* The math library for floating-point arithmetic support (can be
deselected by adding -DNOFLOAT to CFLAGS and removing -lm from
* Many and varied security libraries for building a secure version
(Kerberos, SSL/TLS, SRP, Zlib,...) These are required only if you
select a secure target.
* For the curses-based fullscreen file-ransfer display, the curses
or ncurses header file(s) and library, and probably also the
termcap and/or termlib library. Note that the names and locations
of these files and libraries are likely to change capriciously
with every new release of your Unix product. If you discover that
the C-Kermit build procedure fails because your curses and/or
termxxx headers or libraries are not named or located as expected,
please [77]let us know. In the meantime, work around by installing
* IMPORTANT: Modern Linux distributions might give you the choice
during installation of whether to install the "ncurses development
package" (perhaps called "ncurses-devel"). If you did not install
it, you won't be able to build C-Kermit with curses support
included. In this case, either go back and install ncurses, or
else choose (or create) a non-curses makefile target for your
platform. To install the ncurses developers tools in Red Hat
Linux, do:
mount redhat cdrom
goto RedHat/RPMS
rpm -ivh ncurses-devel*.rpm
or to have the exact name ls ncurse* and load as
rpm -ivh filename
then leave the cdrom and unmount it.
* In AIX you might have to go back and install any or all of:
from the first installation CD.
The makefile might need to be renamed from ckuker.mak to makefile.
a. Type "make xxx" where xxx is the name of the makefile target most
appropriate to your platform, e.g. "make linux", "make aix43",
etc. Read the [78]comments at the top of the makefile for a
complete list of available targets (it's a long list).
b. Test the resulting 'wermit' file (see [79]Section 7 for
suggestions). If it's OK, proceed; otherwise [80]notify us.
NOTE: steps (c) through (e) can be accomplished using the
[81]makefile 'install' target as described in [82]Section 5.4.
c. Rename the 'wermit' file to 'kermit', copy it to the desired
binary directory (such as /usr/local/bin or /opt/something), and
if it is to be used for dialing out, give it the same owner,
group, and permissions as the 'cu' program (IMPORTANT: read
[83]Sections 10 and [84]11 for details).
d. Install the man page,, with your other man pages.
e. Install the accompanying text files (see [85]Section 5).
f. If you want C-Kermit to also offer a Telnet command-line
personality, make a symbolic link as follows:
cd directory-where-kermit-binary-is
ln -s kermit telnet
If you want C-Kermit to be the default Telnet client, make sure
the directory in which you created the symlink is in the PATH
ahead of the where the regular Telnet client is.
g. If you want C-Kermit to also offer an FTP command-line
personality, make a symlink called "ftp" as in (f).
h. If you want C-Kermit to also offer an FTTP command-line
personality, make a symlink called "http" as in (f).
i. If you want to offer an Internet Kermit Service, follow the
directions in the [86]IKSD Administrator's Guide.
4.0. Special Considerations for C-Kermit 8.0
[ [87]Top ] [ [88]Contents ] [ [89]Next ]
Also see: [90]C-Kermit Configuration Options
4.1. [91]The Unix Makefile
4.2. [92]The C-Kermit Initialization File
4.3. [93]The 2.x BSD Makefile
4.4. [94]The Plan 9 Makefile
4.5. [95]Makefile Failures
(Also see the [96]Configurations Options document, [97]Section 8).
Lots of new features have been added in versions 7.0 and 8.0 that
require access to new symbols, APIs, libraries, etc, and this will no
doubt cause problems in compiling, linking, or execution on platforms
where 6.0 and earlier built without incident. This section contains
what we know as of the date of this file.
The first category concerns the new Kermit Service Daemon (IKSD; see
the [98]IKSD Administrator's Guide for details):
The wtmp File
When C-Kermit is started as an IKSD (under inetd), it makes
syslog and wtmp entries, and also keeps its own ftpd-like log.
The code assumes the wtmp log is /var/log/wtmp on Linux and
/usr/adm/wtmp elsewhere. No doubt this assumption will need
adjustment. Use -DWTMPFILE=path to override at compile time
(there is also a runtime override). See [99]iksd.html for
UTMP, utsname(), etc
C-Kermit 7.0 gets as much info as it can about its job --
mainly for IKSD logging -- from utmp. But of course utmp
formats and fields differ, and for that matter, there can be
two different header files, <utmp.h> and <utmpx.h>. Look for
HAVEUTMPX and HAVEUTHOST in [100]ckufio.c and let me know of
any needed adjustments.
Password lookup
IKSD needs to authenticate incoming users against the password
list. In some cases, this requires the addition of -lcrypt
(e.g. in Unixware 2.x). In most others, the crypt functions are
in the regular C library. If you get "crypt" as an unresolved
symbol at link time, add -lcrypt to LIBS. If your site has
local replacement libraries for authentication, you might need
a special LIBS clause such as "LIBS=-L/usr/local/lib -lpwent".
These days most Unix systems take advantage of shadow password
files or Plugable Authentication Modules (PAM). If your system
uses shadow passwords you must add -DCK_SHADOW to the CFLAGS
list. If your system requires PAM you must add -DCK_PAM to the
CFLAGS and -lpam -ldl to LIBS.
This is called by the IKSD at login time to see if a user has
been "turned off". But many Unix platforms lack this function.
In that case, you will get unresolved symbol reports at link
time for _getusershell, _endusershell; to work around, add
This is called by IKSD after successful authentication. But
some platforms do not have this function, so obviously it can't
be called there, in which case add -DNOINITGROUPS.
setreuid(), setreuid(), setregid() not found or "deprecated"
Find out what your Unix variety wants you to use instead, and
make appropriate substitutions in routine zvpass(), module
[101]ckufio.c, and [102]let us know.
IKSD installs a printf() substitute to allow redirection of
printf-like output to the connection. However, this can
conflict with some curses libraries. In this case, separate
binaries must be built for IKSD and non-IKSD use.
If you encounter difficulties with any of the above, and you are not
interested in running C-Kermit as an IKSD, then simply add NOIKSD to
CFLAGS and rebuild. Example:
make sco286
(get lots of errors)
make clean
make sco286 "KFLAGS=-DNOIKSD"
Some non-IKSD things to watch out for:
Return type of main()
The main() routine is in [103]ckcmai.c. If you get complaints
about "main: return type is not blah", define MAINTYPE on the
CC command line, e.g.:
make xxx "KFLAGS=-DMAINTYPE=blah
(where blah is int, long, or whatever). If the complaint is
"Attempt to return a value from a function of type void" then
make xxx "KFLAGS=-DMAINISVOID=blah
DNS Service Records
This feature allows a remote host to redirect C-Kermit to the
appropriate socket for the requested service; e.g. if C-Kermit
requests service "telnet" and the host offers Telnet service on
port 999 rather than the customary port 23. If you get
compile-time complaints about not being able to find
<resolv.h>, <netdb.h>, or <arpa/nameser.h>, add -DNO_DNS_SRV to
CFLAGS. If you get link-time complaints about unresolved
symbols res_search or dn_expand, try adding -lresolve to LIBS.
If "echo \v(ipaddress)" shows an empty string rather than your
local IP address, add -DCKGHNLHOST to CFLAGS and rebuild.
If this file can't be found at compile time, add -DNOREDIRECT
to CFLAGS. This disables the REDIRECT and PIPE commands and
anything else that needs the wait() system service.
C-Kermit can now write syslog records. Some older platforms
might not have the syslog facility. In that case, add
-DNOSYSLOG. Others might have it, but require addition of
-lsocket to LIBS (SCO OSR5 is an example). See [104]Section 15.
If "_putenv" comes up as an undefined symbol, add -DNOPUTENV to
CFLAGS and rebuild.
"Passing arg1 of 'time' from incompatible pointer"
This is a mess. See the mass of #ifdefs in the appropriate
module, [105]ckutio.c or [106]ckufio.c.
Wrong number of arguments. On most platforms, gettimeofday()
takes two arguments, but on a handful of others (e.g. Motorola
System V/88 V4, SNI Reliant UNIX 5.43, etc) it takes one. If
your version of gettimeofday() is being called with two args
but wants one, add -DGTODONEARG.
"Assignment makes pointer from integer without a cast"
This warning might appear in [107]ckutio.c or [108]ckufio.c.
(or elsewhere), and usually can be traced to the use of a
system or library function that returns a pointer but that is
not declared in the system header files even though it should
be. Several functions are commonly associated with this error:
+ getcwd(): Add -DDCLGETCWD to CFLAGS and rebuild.
+ popen() : Add -DDCLPOPEN to CFLAGS and rebuild.
+ fdopen(): Add -DDCLFDOPEN to CFLAGS and rebuild.
"Operands of = have incompatible types"
"Incompatible types in assignment"
If this comes from [109]ckcnet.c and comes from a statement
involving inet_addr(), try adding -DINADDRX to CFLAGS. If that
doesn't help, then try adding -DNOMHHOST.
Complaints about args to get/setsockopt(), getpeername(),
These are all in [110]ckcnet.c. Different platforms and OS's
and versions of the same OS change this all the time: int,
size_t, unsigned long, etc. All the affected variables are
declared according to #ifdefs within ckcnet.c, so find the
declarations and adjust the #ifdefs accordingly.
In case of complaints about "unknown type size_t", add
-DSIZE_T=int (or other appropriate type) to CFLAGS.
'tz' undefined
Use of undefined enum/struct/union 'timezone'
Left of 'tv_sec' specifies undefined struct/union 'timeval' And
similar complaints in [111]ckutio.c: Add -DNOGFTIMER and/or
The new built-in DIRECTORY command should show symlinks like
"ls -l" does. If it does not, check to see if your platform has
the lstat() and readlink() functions. If so, add -DUSE_LSTAT
and -DCKSYMLINK to CFLAGS and rebuild. On the other hand, if
lstat() is unresolved at link time, add -DNOLSTAT to CFLAGS. If
readlink() is also unresolved, add -DNOSYMLINK.
Link-time complains about realpath() -- find the library in
which it resides and add it to LIBS (example for Unixware 7.1:
"-lcudk70") or add -DNOREALPATH to CFLAGS and rebuild. If built
with realpath() but debug log file is truncated or mangled,
ditto (some realpath() implementations behave differently from
others). If built with realpath() and seemingly random core
dumps occur during file path resolution, ditto.
Failure to locate header file <term.h>
Usually happens on Linux systems that have the C compiler
installed, but not the ncurses package (see comments about
selective installs above). Go back and install ncurses, or use
"make linuxnc" (Linux No Curses).
"Can't find shared library"
"Can't find shared library", etc...
You are trying to run a binary that was built on a computer
that has different library versions than your computer, and
your computer's loader is picky about library version numbers.
Rebuild from source on your computer.
Time (struct tm) related difficulties:
Errors like the following:
"ckutio.c", line 11994: incomplete struct/union/enum tm: _tm
"ckutio.c", line 11995: error: cannot dereference non-pointer type
"ckutio.c", line 11995: error: assignment type mismatch
"ckutio.c", line 11997: warning: using out of scope declaration: localtime
"ckutio.c", line 11997: error: unknown operand size: op "="
"ckutio.c", line 11997: error: assignment type mismatch
"ckutio.c", line 11998: error: undefined struct/union member: tm_year
"ckutio.c", line 12000: error: undefined struct/union member: tm_mon
"ckutio.c", line 12001: error: undefined struct/union member: tm_mday
"ckutio.c", line 12002: error: undefined struct/union member: tm_hour
"ckutio.c", line 12003: error: undefined struct/union member: tm_min
"ckutio.c", line 12004: error: undefined struct/union member: tm_sec
are due to failure to include the appropriate time.h header
files. Unix platforms generally have one or more of the
following: <time.h>, <sys/time.h>, and <sys/timeb.h>. Any
combination of these might be required. Defaults are set up for
each makefile target. The defaults can be corrected on the CC
command line by adding the appropriate definition from the
following list to CFLAGS:
-DTIMEH Include <time.h>
-DNOTIMEH Don't include <time.h>
-DSYSTIMEH Include <sys/time.h>
-DNOSYSTIMEH Don't include <sys/time.h>
-DSYSTIMEBH Include <sys/timeb.h>
-DNOSYSTIMEBH Don't include <sys/timeb.h>
Note that <sys/timeb.h> is relatively scarce in the System V
and POSIX environments; the only platform of recent vintage
where it was/is used is OSF/1 and its derivatives (Digital Unix
and Tru64 Unix).
Struct timeval and/or timezone not declared:
In some cases, merely including the appropriate time.h header
files is still not enough. POSIX.1 does not define the timeval
struct, and so the items we need from the header are protected
against us by #ifndef _POSIX_SOURCE or somesuch. In this case,
we have to declare the timeval (and timezone) structs
ourselves. To force this, include -DDCLTIMEVAL in CFLAGS.
Warnings about dn_expand() Argument #4
WARNING: argument is incompatible with prototyp. It's the old
char versus unsigned char stupidity again. Try to find a
compiler switch like GCC's "-funsigned-char". Failing that, add
-DCKQUERYTYPE=xxx to CFLAGS, where xxx is whatever 'man
dn_expand' tells you the type of the 4th argument should be
(presumably either char or unsigned char; in the latter case
use CHAR to avoid confusion caused by multiple words.
Switch Table Overflow (in [112]ckcuni.c)
Compile-time warnings about ck_out() or tgetstr() or tputs():
Easy solution: Add -DNOTERMCAP to CFLAGS. But then you lose the
SCREEN function. Real solution: Try all different combinations
of the following CFLAGS:
Until the warnings go away, except maybe "ck_outc: return with
a value in a function returning void", and in that case also
"Passing arg 1 of to tputs() makes pointer from integer without a
"Undefined symbol: dup2"
"header file 'termcap.h' not found"
Other difficulties are generally of the "where is curses.h and what is
it called this week?" variety (most easily solved by making symlinks
in the include and lib directories), or overzealous complaints
regarding type mismatches in function calls because of the totally
needless and silly signed versus unsigned char conflict (*), etc. In
any case, please send any compilation or linking warnings or errors to
the author, preferably along with fixes.
* C-Kermit does not use the signed property of chars at all
anywhere, ever. So if all chars and char *'s can be made unsigned
at compile time, as they can in gcc with "-funsigned-char", they
should be.
IMPORTANT: If you find any of these hints necessary for a particular
make target (or you hit upon others not listed here), PLEASE SEND A
4.1. The Unix Makefile
[ [114]Top ] [ [115]Contents ] [ [116]Section Contents ] [ [117]Next ]
[ [118]Previous ]
If your distribution does not contain a file with the name "makefile"
or "Makefile", then rename the file called ckuker.mak to makefile:
mv ckuker.mak makefile
Then type "make xxx", where xxx is the platform you want to build
C-Kermit for. These are listed in the [119]comments at the top of the
makefile. For example, to build C-Kermit for Linux, type:
make linux
Here are some typical examples:
Target Description
linux Linux, any version on any hardware platform
openbsd OpenBSD, any version on any hardware platform
aix43 AIX 4.3
aix43g AIX 4.3, built with gcc
solaris9 Solaris 9
solaris9g Solaris 9 built with gcc
hpux1100 HP-UX 11-point-anything
The makefile is quite long, and at least two versions of Unix, SCO
Xenix/286 and 2.x BSD, cannot cope with its length. An attempt to
"make sco286" gives the message "Make: Cannot alloc mem for env..
Stop". Solution: edit away some or all of the nonrelevant material
from the makefile. (A separate version of the makefile is provided for
BSD 2.x: ckubs2.mak but C-Kermit 8.0 can't be built for BSD 2.x -- it
has simply grown too large.)
Some make programs reportedly cannot handle continued lines (lines
ending in backslash (\)). If you have a problem with the makefile, try
editing the makefile to join the continued lines (remove the
backslashes and the following linefeed).
Other makefile troubles may occur because tabs in the makefile have
somehow been converted to spaces. Spaces and tabs are distinct in Unix
Similarly, carriage returns might have been added to the end of each
line, which also proves confusing to most Unix versions of make.
Check to see if there are comments about your particular version in
its makefile target itself. In a text editor such as EMACS or VI,
search for the make entry name followed by a colon, e.g. "linux:" (if
you really are building C-Kermit for Linux, do this now).
Check to see if there are comments about your particular version in
the [120]ckubwr.txt file ([121]CLICK HERE for the Web version).
If you have trouble with building [122]ckwart.c, or running the
resulting wart preprocessor program on [123]ckcpro.w:
1. Just "touch" the [124]ckcpro.c file that comes in the distribution
and then give the "make" command again, or:
2. Compile ckwart.c "by hand": cc -o wart ckwart.c, or:
3. Try various other tricks. E.g. one Linux user reported that that
adding the "static" switch to the rule for building wart fixed
wart: ckwart.$(EXT)
$(CC) -static -o wart ckwart.$(EXT) $(LIBS)
If your compiler supports a compile-time option to treat ALL chars
(and char *'s, etc) as unsigned, by all means use it -- and send me
email to let me know what it is (I already know about gcc
To add compilation options (which are explained later in this
document) to your makefile target without editing the makefile,
include "KFLAGS=..." on the make command line, for example:
Multiple options must be separated by spaces. Quotes are necessary if
the KFLAGS= clause includes spaces. The KFLAGS are added to the end of
the CFLAGS that are defined in the selected makefile target. For
example, the "bsd" entry includes -DBSD4 -DTCPSOCKET, so the second
example above compiles Kermit with the following options:
(Notice how "-UTCPSOCKET" is used to negate the effect of the
"-DTCPSOCKET" option that is included in the makefile target.)
WARNING: Be careful with KFLAGS. If you build C-Kermit, change some
files, and then run make again using the same make entry but
specifying different KFLAGS than last time, make won't detect it and
you could easily wind up with inconsistent object modules, e.g. some
of them built with a certain option, others not. When in doubt, "make
clean" first to make sure all your object files are consistent.
Similarly, if you change CFLAGS, LIBS, or any other items in the
makefile, or you rebuild using a different makefile target, "make
clean" first.
If you create a new makefile target, use static linking if possible.
Even though this makes your C-Kermit binary bigger, the resulting
binary will be more portable. Dynamically linked binaries tend to run
only on the exact configuration and version where they were built; on
others, invocation tends to fail with a message like:
Can't find shared library ""
4.2. The C-Kermit Initialization File
[ [125]Top ] [ [126]Contents ] [ [127]Section Contents ] [ [128]Next ]
[ [129]Previous ]
(This section is obsolete.) Read [130]Section 5 about the
initialization file.
4.3. The 2.x BSD Makefile
[ [131]Top ] [ [132]Contents ] [ [133]Section Contents ] [ [134]Next ]
[ [135]Previous ]
This section is obsolete. C-Kermit 6.0 was the last release that
could be built on PDP-11 based BSD versions.
4.4. The Plan 9 Makefile
[ [136]Top ] [ [137]Contents ] [ [138]Section Contents ] [ [139]Next ]
[ [140]Previous ]
Use the separate makefile [141] NOTE: The Plan 9 version of
C-Kermit 8.0 has not yet been built. There should be no impediment to
building it. However, even when built successfully, certain key
features are missing, notably TCP/IP networking.
4.5. Makefile Failures
[ [142]Top ] [ [143]Contents ] [ [144]Section Contents ] [
[145]Previous ]
First, be sure the source files are stored on your current disk and
directory with the right names (in lowercase). Second, make sure that
the makefile itself does not contain any lines with leading spaces:
indented lines must all start with horizontal TAB, and no spaces.
Then make sure that your Unix PATH is defined to find the appropriate
compiler for your makefile target. For example, on SunOS systems,
"make sunos41" builds C-Kermit for the BSD environment, and assumes
that /usr/ucb/cc will be used for compilation and linking. If your
PATH has /usr/5bin ahead of /usr/ucb, you can have problems at compile
or link time (a commonly reported symptom is the inability to find
"ftime" during linking). Fix such problems by redefining your Unix
PATH, or by specifying the appropriate "cc" in CC= and CC2= statements
in your makefile target.
During edits 166-167, considerable effort went into making C-Kermit
compilable by ANSI C compilers. This includes prototyping all of
C-Kermit's functions, and including the ANSI-defined system header
files for system and library functions, as defined in K&R, second
edition: <string.h>, <stdlib.h>, <unistd.h> (except in NeXTSTEP this
is <libc.h>), and <sys/stdtypes.h>. If you get warnings about any of
these header files not being found, or about argument mismatches
involving pid_t, uid_t, or gid_t, look in ckcdeb.h and make
amendments. C-Kermit assumes it is being compiled by an ANSI-compliant
C compiler if __STDC__ is defined, normally defined by the compiler
itself. You can force ANSI compilation without defining __STDC__
(which some compilers won't let you define) by including -DCK_ANSIC on
the cc command line.
On the other hand, if your compiler defines __STDC__ but still
complains about the syntax of Kermit's function prototypes, you can
disable the ANSI-style function prototyping by including -DNOANSI on
the command line.
For SCO OpenServer, UNIX, ODT, and XENIX compilations, be sure to pick
the most appropriate [146]makefile target, and be sure you have
installed an SCO development system that is keyed to your exact SCO
operating system release, down to the minor version (like 2.3.1).
Also note that SCO distributes some of its libraries in encrypted
form, and they must be decrypted before C-Kermit can be linked with
them. If not, you might see a message like:
ld: file /usr/lib/libsocket.a is of unknown type: magic number = 6365
To decrypt, you must supply a key (password) that came with your
license. Call SCO for further info.
If your compiler uses something other than int for the pid (process
id) data type, put -DPID_T=pid_t or whatever in your CFLAGS.
If you get complaints about unknown data types uid_t and gid_t, put
-DUID_T=xxx -DGID_T=yyy in your CFLAGS, where xxx and yyy are the
appropriate types.
If your compilation fails because of conflicting or duplicate
declarations for sys_errlist, add -DUSE_STRERROR or -DNDSYSERRLIST to
If your compilation dies because getpwnam() is being redeclared (or
because of "conflicting types for getwpnam"), add -DNDGPWNAM to your
CFLAGS. If that doesn't work, then add -DDCGPWNAM to your CFLAGS (see
ckufio.c around line 440).
If the compiler complains about the declaration of getpwnam() during
an ANSI C compilation, remove the declaration from ckufio.c or change
the argument in the prototype from (char *) to (const char *).
If you get complaints that getpwuid() is being called with an improper
type, put -DPWID_T=xx in your CFLAGS.
If you get compile-time warnings that t_brkc or t_eofc (tchars
structure members, used in BSD-based versions) are undefined, or
structure-member- related warnings that might be traced to this fact,
If you get a linker message to the effect that _setreuid or _setregid
is not defined, add -DNOSETREU to CFLAGS, or add -DCKTYP_H=blah to
CFLAGS to make C-Kermit read the right <types.h>-kind-of-file to pick
up these definitions.
If you get a message that _popen is undefined, add -DNOPOPEN to
If you get a complaint at compile time about an illegal
pointer-integer combination in ckufio.c involving popen(), or at link
time that _popen is an undefined symbol, add the declaration "FILE
*popen();" to the function zxcmd() in ckufio.c (this declaration is
supposed to be in <stdio.h>). If making this change does not help,
then apparently your Unix does not have the popen() function, so you
should add -DNOPOPEN to your make entry, in which case certain
functions involving "file" i/o to the standard input and output of
subprocesses will not be available.
If your linker complains that _getcwd is undefined, you can add a
getcwd() function to ckufio.c, or add it to your libc.a library using
#include <stdio.h>
char *
getcwd(buf,size) char *buf; int size; {
#ifndef NOPOPEN
FILE *popen();
FILE *pfp;
if (!buf) return(NULL);
if (!(pfp = popen("pwd","r"))) return(NULL);
buf[strlen(buf)-1] = '\0';
return((char *)buf);
buf[0] = '\0';
#endif /* NOPOPEN */
#ifdef NOPOPEN
FILE *popen(s,t) char *s,*t; {
#endif /* NOPOPEN */
If you get complaints about NPROC having an invalid value, add a valid
definition for it (depends on your system), as in the cray entry.
If you get some symbol that's multiply defined, it probably means that
a variable name used by Kermit is also used in one of your system
libraries that Kermit is linked with. For example, under PC/IX some
library has a variable or function called "data", and the variable
"data" is also used extensively by Kermit. Rather than edit the Kermit
source files, just put a -D in the make entry CFLAGS to change the
Kermit symbol at compile time. In this example, it might be
Some symbol is defined in your system's header files, but it produces
conflicts with, or undesired results from, Kermit. Try undefining the
symbol in the makefile target's CFLAGS, for example -UFIONREAD.
Some well-known symbol is missing from your system header files. Try
defining in the makefile target's CFLAGS, for example -DFREAD=1.
You get many warnings about pointer mismatches. This probably means
that Kermit is assuming an int type for signal() when it should be
void, or vice-versa. Try adding -DSIG_I (for integer signal()) or
-DSIG_V (for void) to CFLAGS. Or just include KFLAGS=-DSIG_V (or
whatever) in your "make" command, for example:
make bsd KFLAGS=-DSIG_V
You get many messages about variables that are declared and/or set but
never used. It is difficult to avoid these because of all the
conditional compilation in the program. Ignore these messages.
Some of C-Kermit's modules are so large, or contain so many character
string constants, or are so offensive in some other way, that some C
compilers give up and refuse to compile them. This is usually because
the -O (optimize) option is included in the make entry. If this
happens to you, you can (a) remove the -O option from the make entry,
which will turn off the optimizer for ALL modules; or (b) compile the
offending module(s) by hand, including all the switches from make
entry except for -O, and then give the appropriate "make" command
again; or (c) increase the value of the -Olimit option, if your
compiler supports this option; or (d) change the [147]makefile target
to first compile each offending module explicitly without
optimization, then compile the others normally (with optimization),
for example:
#Fortune 32:16, For:Pro 2.1 (mostly like 4.1bsd)
@echo 'Making C-Kermit $(CKVER) for Fortune 32:16 For:Pro 2.1...'
"LNKFLAGS= -n -s" "LIBS= -lcurses -ltermcap -lv -lnet"
As an extreme example, some compilers (e.g. gcc on the DG AViiON) have
been known to dump core when trying to compile ckwart.c with
optimization. So just do this one "by hand":
cc -o wart ckwart.c
touch ckcpro.c
and then give the "make" command again.
Speaking of wart, it is unavoidable that some picky compilers might
generate "statement unreachable" messages when compiling ckcpro.c.
Unreachable statements can be generated by the wart program, which
generates ckcpro.c automatically from [148]ckcpro.w, which translates
lex-like state/input constructions into a big switch/case
Some function in Kermit wreaks havoc when it is called. Change all
invocations of the function into a macro that evaluates to the
appropriate return code that would have been returned by the function
had it been called and failed, for example: -Dzkself()=0. Obviously
not a good idea if the function is really needed.
If you have just installed SunOS 4.1.2 or 4.1.3, you might find that
C-Kermit (and any other C program) fails to link because of unresolved
references from within libc. This is because of a mistake in Sun's
/usr/lib/shlib.etc files for building the new libc. Change the libc
Makefile so that the "ld" lines have "-ldl" at the end. Change the
README file to say "mv xccs.multibyte. xccs.multibyte.o" and follow
that instruction.
[ [149]Top ] [ [150]Contents ] [ [151]Next ] [ [152]Previous ]
5.1. [153]The C-Kermit Initialization File
5.2. [154]Text Files
5.3. [155]Installing the Kermit Files
5.4. [156]The Makefile Install Target
The C-Kermit executable does not need any external files to run.
Unlike, say, the cu program, which on most platforms is useless unless
you (as root) edit the /usr/spool/uucp/Systems and
/usr/spool/uucp/Devices files to supply whatever obscure and
undocumented syntax is required to match some supposedly user-friendly
mnemonic to the real pathname of whatever device you want to use,
Kermit runs on its own without needing any external configuration
files, and lets you refer to device (and network hosts and services)
by their own natural undisguised names.
Nevertheless, a number of external files can be installed along with
the C-Kermit executable if you wish. These include configuration and
customization files that are read by Kermit as well as documentation
files to be read by people. All of this material is (a) optional, and
(b) available on the Kermit website:
and usually in a more pleasant form, perhaps also with updated
content. So if your computer is on the Internet, there is no need to
install anything but the Kermit executable if users know how to find
the Kermit website (and if they don't, Kermit's "help" command tells
5.1. The C-Kermit Initialization File
In C-Kermit 7.0 and earlier, the standard initialization file was a
key C-Kermit component because:
a. It "loaded" the dialing and network directories.
b. It defined all the macros and variables for the services
c. It defined macros for quickly changing Kermit's file-transfer
performance tuning.
The standard initialization file is quite long (more than 600 lines)
and requires noticeable processing time (the slower the computer, the
more noticeable), yet few people actually use the services directory,
whose definition takes up most of its bulk. Meanwhile, in C-Kermit
8.0, many of the remaining functions of the standard initialization
file are now built in; for example, the FAST, CAUTIOUS, and ROBUST
More to the point, many of the settings that could be made only in the
initialization and customization files can now be picked up from
environment variables. The first group identifies initialization and
directory files:
The path of your Kermit initialization file, if any. This
overrides the built-in search for $HOME/.kermrc.
The character set used for encoding local text files.
The full pathname of one or more Kermit dialing directory
files. Equivalent to SET DIAL DIRECTORY.
The full pathname of one or more Kermit network directory
files. Equivalent to SET NETWORK DIRECTORY.
The full pathname of a directory containing Kermit (if any)
containing ckubwr.txt and other Kermit text files. Overrides
Kermit's built-in search for this directory.
The next group is related to dialing modems:
The telephonic numeric country code for this location, e.g. 1
for North America or 39 for Italy. It is recommended that this
one be set for all users, system-wide. Not only is it used to
process portable-format dialing directory entries, but it is
also compared against Kermit's built-in list of "tone
countries" to see if tone dialing can be used. Equivalent to
Kermit's SET DIAL COUNTRY-CODE command.
The telephonic numeric area code for this location, e.g. 212
for Manhattan, New York, USA. Recommend this one also be set
system-wide, so shared portable-format dialing directories will
work automatically for everybody. Equivalent to Kermit's SET
TONE or PULSE. Equivalent to Kermit's SET DIAL METHOD command.
If a dial method is not set explicitly (or implicitly from the
country code), Kermit does not specify a dialing method, and
uses the modem's default method, which tends to be pulse.
The telephonic numeric international dialing prefix for this
location. Equivalent to Kermit's SET DIAL INTL-PREFIX command.
The telephonic numeric long-distance dialing prefix for this
location. Equivalent to Kermit's SET DIAL LD-PREFIX command.
The telephonic numeric PBX internal call prefix for this
location. Equivalent to Kermit's SET DIAL PBX-INSIDE-PREFIX
The telephonic numeric PBX external call prefix for this
location. Equivalent to Kermit's SET DIAL PBX-OUTSIDE-PREFIX
The telephonic numeric PBX exchange (first part of the
subscriber number). Equivalent to Kermit's SET DIAL
A list of one or more telephonic numeric toll-free area codes.
The telephonic numeric toll-free dialing prefix, in case it is
different from the long-distance prefix. Equivalent to Kermit's
The final group includes well-known environment variables that are
also used by Kermit:
Where the CD command should look for relative directory names.
The path of your Unix shell. Used by the RUN (!) command to
choose the shell to execute its arguments.
Your Unix username.
The name or path of your preferred editor (used by the EDIT
command). Equivalent to SET EDITOR.
The name or path of your preferred web browser (used by the
BROWSE command). Equivalent to Kermit's SET BROWSER command.
Does this mean the initialization file can be abolished? I think so.
Here's why:
* Kermit already does everything most people want it to do without
* Important site-specific customizations can be done with global
environment variables.
* There is no longer any need for everybody to have to use the
standard initialization file.
* This means that your initialization file, if you want one, can
contain your own personal settings, definitions, and preferences,
rather than 600 lines of "standard" setups.
* If you still want the services directory, you can either TAKE the
standard initialization file (which must be named anything other
than $HOME/.kermrc to avoid being executed automatically every
time you start Kermit), or you can make it a kerbang script and
execute it "directly" (the [158]makefile install target does this
for you by putting ckermit.ini in the same directory as the Kermit
binary, adding the appropriate Kerbang line to the top, and giving
it execute permission).
In fact, you can put any number of kerbang scripts in your PATH to
start up C-Kermit in different ways, to have it adopt certain
settings, make particular connections, execute complicated scripts,
whatever you want.
5.2. Text Files
These are entirely optional. Many of them are to be found at the
Kermit website in HTML form (i.e. as Web pages with clickable links,
etc), and very likely also more up to date. Plain-text files that
correspond to Web pages were simply "dumped" by Lynx from the website
to plain ASCII text. The format is whatever Lynx uses for this
purpose. If you wish, you can install them on your computer as
described in the [159]next section.
Copyright notice, permissions, and disclaimer.
The standard initialization file, intended more for reference
(in most cases) than actual use; see [162]Section 5.1.
A sample customization file.
Supplement to [165]Using C-Kermit for version 7.0. Available on
the Kermit website as:
Supplement to [168]Using C-Kermit for version 8.0. Available on
the Kermit website as:
The general C-Kermit hints and tips ("beware") file. Available
on the Kermit website as:
The Unix-specific C-Kermit hints and tips file. Available on
the Kermit website as:
Unix C-Kermit Installation Instructions (this file). Available
on the Kermit website as:
C-Kermit compile-time configuration options. Available on the
Kermit website as:
The C-Kermit program logic manual. Available on the Kermit
website as:
Certificate Authority certificates for secure connections (see
[181]Section 16).
5.3. Installing the Kermit Files
There is an "install" target in the [182]makefile that you can use if
you wish. However, since every site has its own layout and
requirements, it is often better to install the Kermit files by hand.
You don't have to use the makefile install target to install C-Kermit.
This is especially true since not all sites build C-Kermit from
source, and therefore might not even have the makefile. But you should
read this section in any case.
If your computer already has an older version of C-Kermit
installed, you should rename it (e.g. to "kermit6" or "kermit7") so
in case you have any trouble with the new version, the old one is
still available.
In most cases, you need to be root to install C-Kermit, if only to
gain write access to directories in which the binary and manual page
are to be copied. The C-Kermit binary should be installed in a
directory that is in the users' PATH, but that is not likely to be
overwritten when you install a new version of the operating system. A
good candidate would be the /usr/local/bin/ directory, but the
specific choice is site dependent. Example (assuming the appropriate
Kermit binary is stored in your current directory as "wermit", e.g.
because you just built it from source and that's the name the makefile
gave it):
mv wermit /usr/local/bin/kermit
chmod 755 /usr/local/bin/kermit
or (only after you finish reading this section!) simply:
make install
something to give it access to the dialout devices and lockfile
directories. The 'install' target does not attempt to set Kermit's
owner, group, and permissions to allow dialing out. This requires
privileges, open eyes, and human decision-making. Please read
[183]Sections 10 and [184]11 below, make the necessary decisions, and
then implement them by hand as described in those sections.
You should also install the man page, which is called, in
the man page directory for local commands, such as /usr/man/man1/,
renamed appropriately, e.g. to kermit.1. This is also taken care of by
"make install".
Optionally, the text files listed in the [185]previous section can be
placed in a publicly readable directory. Suggested directory names
(or any of these without the "/kermit"). Upon startup, C-Kermit checks
the following environment variables whose purpose is to specify the
directory where the C-Kermit text files are, in the following order:
If either of these is defined, C-Kermit checks for the existence of
the ckubwr.txt file (Unix C-Kermit Hints and Tips). If not found, it
checks the directories listed above (both with and without the
"/kermit") plus several others to see if they contain the ckubwr.txt
file. If found, various C-Kermit messages can refer the user to this
Finally, if you want to put the source code files somewhere for people
to look at, you can do that too.
5.4. The Makefile Install Target
The makefile "install" target does almost everything for you if you
give it the information it needs by setting the variables described
below. You can use this target if:
* You downloaded the [186]complete C-Kermit archive and built
C-Kermit from source; or:
* You downloaded an [187]individual C-Kermit binary and the
[188]C-Kermit text-file archive, and your computer has a "make"
Here are the parameters you need to know:
Name of the binary you want to install as "kermit". Default:
(lower case) If you define this variable, its value is
prepended to all the following xxxDIR variables (8.0.211 and
If you want to install the Kermit files in a directory
structure like /opt/kermit/bin/, /opt/kermit/doc/,
/opt/kermit/src/, then define DESTIR as the root of this
structure; for example, /opt/kermit. The DESTDIR string should
not end with a slash. By default, DESTDIR is not defined. If it
is defined, but the directory does not exist, the makefile
attempts to create it, which might require you to be root. Even
so, this can fail if any segments in the path except the last
one do not already exist. WARNING: If the makefile creates any
directories, it gives them a mode of 755, and the default owner
and group. Modify these by hand if necessary.
Directory in which to install the Kermit binary (and the
standard C-Kermit initialization file, if it is found, as a
Kerbang script). If DESTDIR is defined, BINDIR must start with
a slash. BINDIR must not end with a slash. If DESTDIR is
defined, BINDIR is a subdirectory of DESTDIR. If BINDIR does
not exist, the makefile attempts to create it as with DESTDIR.
Default: /usr/local/bin.
Directory in which to install the C-Kermit manual page as
"kermit" followed by the manual-chapter extension (next item).
Default: /usr/man/man1. If MANDIR is defined, the directory
must already exist.
Extension for the manual page. Default: 1 (digit one).
Directory in which to install the C-Kermit source code. If
DESTDIR is defined, this is a subdirectory of DESTDIR. Default:
For secure builds only: Directory in which to install the
ca_certs.pem file. This must be the verification directory used
by programs that use the SSL libraries at your site. Default:
none. Possibilities include: /usr/local/ssl, /opt/ssl,
/usr/lib/ssl, . . . If CERTDIR is defined, the directory
must already exist.
Directory in which to install the C-Kermit text files. If
DESTDIR is defined, this is a subdirectory of DESTDIR. Default:
None. If INFODIR is defined but does not exist, the makefile
attempts to create it, as with DESTDIR.
make install
Installs "wermit" as /usr/local/bin/kermit with permissions
755, the default owner and group, and no special privileges.
The manual page is installed as /usr/man/man1/kermit.1. Text
files are not copied anywhere, nor are the sources.
make MANDIR= install
Just like "make install" but does not attempt to install the
manual page.
make DESTDIR=/opt/kermit BINDIR=/bin SRCDIR=/src INFODIR=/doc install
Installs the Kermit binary "wermit" as /opt/kermit/bin/kermit,
puts the source code in /opt/kermit/src, and puts the text
files in /opt/kermit/doc, creating the directories if they
don't already exist, and puts the man page in the default
make BINDIR=/usr/local/bin CERTDIR=/usr/local/ssl install
Installs the Kerberized Kermit binary "wermit" as
/usr/local/bin/kermit, puts the CA Certificates file in
/usr/local/ssl/, and the man page in the normal place.
For definitive information, see the makefile. The following is
excerpted from the 8.0.211 makefile:
# The following symbols are used to specify library and header file locations
# Redefine them to the values used on your system by:
# . editing this file
# . defining the values on the command line
# . defining the values in the environment and use the -e option
prefix = /usr/local
srproot = $(prefix)
sslroot = $(prefix)
manroot = $(prefix)
WERMIT = makewhat
BINARY = wermit
BINDIR = $(prefix)/bin
MANDIR = $(manroot)/man/man1
[ [189]Top ] [ [190]Contents ] [ [191]Next ] [ [192]Previous ]
This section is obsolete. We don't distribute C-Kermit on diskettes
any more because (a)there is no demand, and (b) it no longer fits.
If you received a DOS-format diskette containing a binary executable
C-Kermit program plus supporting text files, be sure to chmod +x the
executable before attempting to run it.
In version 5A(190) and later, all the text files on the C-Kermit
DOS-format diskettes are in Unix format: LF at the end of each line
rather than CRLF. This means that no conversions are necessary when
copying to your Unix file system, and that all the files on the
diskette, text and binary, can be copied together. The following
comments apply to the DOS-format diskettes furnished with version
5A(189) and earlier or to other DOS-format diskettes you might have
obtained from other sources.
If you have received C-Kermit on MS-DOS format diskettes (such as
those distributed by Columbia University), you should make sure that
your DOS-to-Unix conversion utility (such as "dosread") both: (1)
changes line terminators in all files from carriage-return linefeed
(CRLF) to just linefeed (LF) (such as "dosread -a") and remove any
Ctrl-Z's, and (2) that all filenames are converted from uppercase to
lowercase. If these conversions were not done, you can use the
following shell script on your Unix system to do them:
---(cut here)---
# Shell script to convert C-Kermit DOS-format files into Unix format.
# Lowercases the filenames, strips out carriage returns and Ctrl-Z's.
x=$1 # the name of the source directory
y=$2 # the name of the target directory if [ $# -lt 2 ]; then
echo "usage: $0 source-directory target-directory"
exit 1
if cd $1 ; then
echo "Converting files from $1 to $2"
echo "$0: cannot cd to $1"
exit 1
for i in *; do
j=`echo $i | tr 'A-Z' 'a-z'`
echo $x/$i =\> $y/$j
tr -d '\015\032' < $i > $y/$j
---(cut here)---
Cut out this shell script, save it as "" (or any other name
you prefer), then "chmod +x". Then, create a new, empty
directory to put the converted files in, and then " /xxx
/yyy" where /xxx is the name of the directory where the PC-format
files are, and /yyy is the name of the new, empty directory. The
converted files will appear in the new directory.
[ [193]Top ] [ [194]Contents ] [ [195]Next ] [ [196]Previous ]
First some quick checks for problems that can be easily corrected by
recompiling with different options:
DIRECTORY listing is garbage
Permissions, size, and date are random garbage (but the
filenames are correct) in a C-Kermit DIRECTORY listing. On some
platforms, the lstat() function is present but simply doesn't
work; try adding -DNOLSTAT to CFLAGS and rebuild. If that
doesn't fix it, also add -DNOLINKBITS. If it's still not fixed,
When you make a connection with C-Kermit and transfer files
using the fullscreen (curses) file-transfer display, and then
get the C-Kermit> prompt back afterwards, do characters echo
when you type them? If not, the curses library has altered the
buffering of /dev/tty. Try rebuilding with KFLAGS=-DCK_NEWTERM.
If it already has -DCK_NEWTERM in CFLAGS, try removing it. If
that doesn't help, then rebuild with -DNONOSETBUF (yes, two
NO's). If none of this works (and you can't fix the code), then
either don't use the fullscreen display, or rebuild with
Ctrl-L or any SCREEN command crashes C-Kermit:
Rebuild with -DNOTERMCAP.
No prompt after CONNECT:
After escaping back from CONNECT mode, does your C-Kermit>
prompt disappear? (Yet, typing "?" still produces a command
list, etc) In that case, add -DCKCONINTB4CB to CFLAGS and
Here is a more thorough checklist can use to tell whether your version
of C-Kermit was built correctly for your Unix system, with hints on
how to fix or work around problems:
a. Start C-Kermit (usually by typing "./wermit" in the directory
where you ran the makefile). Do you see the C-Kermit> prompt? If
not, C-Kermit incorrectly deduced that it was running in the
background. The test is in conbgt() in [197]ckutio.c. If you can
fix it for your system, please send in the fix (Hint: read about
"PID_T" below). Otherwise, you can force C-Kermit to foreground
mode by starting it with the -z command line option, as in "kermit
-z", or giving the interactive command SET BACKGROUND OFF.
b. When you type characters at the C-Kermit prompt, do they echo
immediately? If not, something is wrong with concb() and probably
the other terminal mode settings routines in [198]ckutio.c. Be
sure you have used the most appropriate make entry.
c. At the C-Kermit> prompt, type "send ./?". C-Kermit should list all
the files in the current directory. If not, it was built for the
wrong type of Unix file system. Details below. In the meantime,
d. CD to a directory that contains a variety of files, symlinks, and
subdirectories and give a DIRECTORY command at the C-Kermit>
prompt. Do the permissions, size, and date appear correct? If not
see [199]Section 4.0.
e. Assuming your platform supports long file names, create a file
with a long name in your current directory, e.g.:
$ touch thisisafilewithaveryveryveryveryveryveryveryverylooooooooongname
(you might need to make it longer than this, perhaps as long as
257 or even 1025 characters).
Check with ls to see if your version of Unix truncated the name.
Now start C-Kermit and type "send thisis<ESC>". Does Kermit
complete the name, showing the same name as ls did? If not, wrong
filesystem. Read on.
f. Make sure that Kermit has the maximum path length right. Just type
SHOW FILE and see what it says about this. If it is too short,
there could be some problems at runtime. To correct, look in
[200]ckcdeb.h to see how the symbol CKMAXPATH is set and make any
needed adjustments.
g. Send a file to your new Kermit program from a different Kermit
program that is known to work. Is the date/timestamp of the new
file identical to the original? If not, adjustments are needed in
zstrdt() in [201]ckufio.c.
h. Go to another computer (Computer B) from which you can send files
to C-Kermit. Connect Computer B to the computer (A) where you are
testing C-Kermit. Then:
i. Send a file from B to A. Make sure it transferred OK and was
created with the the right name.
j. Send a file from B to A, specifying an "as-name" that is very,
very long (longer than the maximum name length on computer A).
Check to make sure that the file was received OK and that its name
was truncated to Computer A's maximum length. If not, check the
MAXNAMLEN definition in [202]ckufio.c.
k. Tell C-Kermit on Computer A to "set receive pathnames relative"
and then send it a file from Computer B specifying an as-name that
contains several directory segments:
send foo dir1/dir2/dir3/foo
Check to make sure that dir1/dir2/dir3/foo was created in Computer
A's current directory (i.e. that three levels of directories were
l. Repeat step k, but make each path segment in the pathname longer
than Computer A's maximum name length. Make sure each directory
name, and the final filename, were truncated properly.
m. Type Ctrl-C (or whatever your Unix interrupt character is) at the
prompt. Do you get "^C..." and a new prompt? If instead, you get a
core dump (this shouldn't happen any more) "rm core" and then
rebuild with -DNOCCTRAP added to your CFLAGS. If it did work, then
type another Ctrl-C. If this does the same thing as the first one,
then Ctrl-C handling is OK. Otherwise, the SIGINT signal is either
not getting re-armed (shouldn't happen) or is being masked off
after the first time it is caught, in which case, if your Unix is
POSIX-based, try rebuilding C-Kermit with -DCK_POSIX_SIG.
n. Type Ctrl-Z (or whatever your Unix suspend character is) to put
C-Kermit in the background. Did it work? If nothing happened, then
(a)your version of Unix does not support job control, or (b) your
version of C-Kermit was probably built with -DNOJC. If your
session became totally frozen, then you are probably running
C-Kermit on a Unix version that supports job control, but under a
shell that doesn't. If that's not the case, look in the congm()
and psuspend() routines in [203]ckutio.c and see if you can figure
out what's wrong. If you can't, rebuild with -DNOJC.
o. Give a SET LINE command for a dialout device, e.g. "set line
/dev/tty00". If you got some kind of permission or access denied
message, go read [204]Section 10 and then come back here.
p. After giving a successful SET LINE command, type "show comm" to
see the communication parameters. Do they make sense?
q. Type "set speed ?" and observe the list of available speeds. Is it
what you expected? If not, see [205]Section 2) of the
[206]Configurations Options document.
r. Give a SET SPEED command to change the device's speed. Did it
work? (Type "show comm" again to check.)
s. Try dialing out: SET MODEM TYPE , SET LINE , SET SPEED , DIAL . If
it doesn't work, keep reading. After dialing, can you REDIAL?
t. If your version was built with TCP/IP network support, try the
TELNET command.
u. Transfer some files in remote mode on incoming asynchronous serial
(direct or modem) connections, and on incoming network (telnet,
rlogin, terminal server) connections. If you get lots of errors,
try different SET FLOW settings on the remote Kermit program.
v. Establish a serial connection from C-Kermit to another computer
(direct or dialed) and transfer some files. If you have network
support, do the same with a network connection.
w. If your version was built with fullscreen file transfer display
support, check that it works during local-mode file transfer.
Also, check C-Kermit's operation afterwards: is the echoing funny?
etc etc. If there are problems, see [207]Section 4.
x. If your version was built with script programming language
support, TAKE the ckedemo.ksc file to give it a workout.
y. Does C-Kermit interlock correctly with UUCP-family programs (cu,
tip, uucp, etc)? If not, read the section [208]DIALING OUT AND
z. Modem signals... Give a SET LINE command to a serial device and
then type the SHOW MODEM command. If it says "Modem signals
unavailable in this version of Kermit", then you might want to
look at the ttgmdm() routine in [209]ckutio.c and add the needed
code -- if indeed your version of Unix provides a way to get modem
signals (some don't; e.g. modem signals are a foreign concept to
POSIX, requiring politically incorrect workarounds).
aa. If it says "Modem signals unavailable", then it is likely that the
API for getting modem signals is provided, but it doesn't actually
do anything (e.g. ioctl(ttyfd,TIOCMGET,&x) returns EINVAL).
ab. In any case, it still should be able to manipulate the DTR signal.
To test, SET LINE , SET MODEM NONE, and HANGUP. The DTR light
should go out momentarily. If it doesn't, see if you can add the
needed code for your system to the tthang() routine in
ac. If your version of Kermit has the SET FLOW RTS/CTS command, check
to see if it works: give Kermit this command, set your modem for
RTS/CTS, transfer some files (using big packet and window sizes)
and watch the RTS and CTS lights on the modem. If they go on and
off (and Kermit does not get packet errors), then it works. If
your version of Kermit does not have this command, but your
version of Unix does support hardware flow control, take a look at
the tthflow() command in [211]ckutio.c and see if you can add the
needed code (see the section on [212]HARDWARE FLOW CONTROL below).
(And please [213]send back any added code, so that others can
benefit from it and it can be carried forward into future
ad. If C-Kermit starts normally and issues its prompt, echoing is
normal, etc, but then after returning from a CONNECT session, the
prompt no longer appears, try rebuilding with -DCKCONINTB4CB.
ae. (8.0.206 or later) Type some commands at the C-Kermit prompt. Can
you use the Up-arrow and Down-arrow keys on your keyboard to
access Kermit's command history? If not, and you're a programmer,
take a look at the USE_ARROWKEYS sections of ckucmd.c.
[ [214]Top ] [ [215]Contents ] [ [216]Next ] [ [217]Previous ]
Also see: [218]C-Kermit Configuration Options
a. Many of C-Kermit's options and features can be deselected at
compile time. The greatest savings at the least sacrifice in
functionality is to disable the logging of debug information by
defining NODEBUG during compilation. See the [219]Configurations
Options document for further information.
b. Use shared libraries rather than static linking. This is the
default on many Unix systems anyway. However, executables built
for dynamic linking with shared libraries are generally not
portable away from the machine they were built on, so this is
recommended if the binary is for your use only.
c. Most Unix systems have a "strip" command to remove symbol table
information from an executable program image. "man strip" for
further information. The same effect can be achieved by including
"-s" among the link flags when building C-Kermit.
d. SCO, Interactive, and some other Unix versions have an "mcs"
command. "mcs -d wermit" can be used to delete the contents of the
".comment" section from the executable program image.
e. Many modern optimizers can be instructed to optimize for space
rather than execution efficiency. Check the CFLAGS in the makefile
target, adjust as desired.
[ [220]Top ] [ [221]Contents ] [ [222]Next ] [ [223]Previous ]
9.1 [224]Standards
9.1.1. [225]POSIX
9.1.2. [226]ANSI C
9.1.3. [227]Other Standards
9.2. [228]Library Issues
9.3. [229]Unix File System Peculiarities
9.4. [230]Hardware Flow Control
9.5. [231]Terminal Speeds
9.6. [232]Millisecond Sleeps
9.7. [233]Nondestructive Input Buffer Peeking
9.8. [234]Other System-Dependent Features
9.9. [235]Terminal Interruption
There are several major varieties of Unix: Bell Laboratories Seventh
Edition, AT&T System V, Berkeley Standard Distribution (BSD), and
POSIX. Each has many, many subvarieties and descendents, and there are
also hybrids that exhibit symptoms of two or more varieties, plus
special quirks of their own.
Seventh edition versions of C-Kermit include the compile-time option
-DV7 in the CFLAGS string in the makefile target. Various V7-based
implementations are also supported: -DCOHERENT, -DMINIX, etc.
AT&T-based versions of Unix Kermit include the compile-time option
-DATTSV (standing for AT&mp;T Unix System V). This applies to System
III and to System V up to and including Release 2. For System V
Release 3, the flag -DSVR3 should be used instead (which also implies
-DATTSV). This is because the data type of signal() and several other
functions was changed between SVR2 and SVR3. For System V Release 4,
include -DSVR4 because of changes in UUCP lockfile conventions; this
also implies -DSVR3 and -DATTSV.
For BSD, the flag -BSDxx must be included, where xx is the BSD version
number, for example BSD4 (for version 4.2 or later, using only 4.2
features), -DBSD41 (for BSD 4.1 only), -DBSD43 (for 4.3), -DBSD29 (BSD
2.9 for DEC PDP-11s). -DBSD44 is for 4.4BSD, which is the basis of
FreeBSD, NetBSD, OpenBSD, BSDI, and Mac OS X, and which contains many
POSIX features, and has little relation to 4.3BSD and earlier.
For POSIX, include the flag -DPOSIX. POSIX defines a whole new set of
terminal i/o functions that are not found in traditional AT&T or
Berkeley implementations, and also defines the symbol _POSIX_SOURCE,
which is used in many system and library header files, mainly to
disable non-POSIX (i.e. useful) features.
Note (circa 1997): In order to enable serial speeds higher than 38400
bps, it is generally necessary to add -DPOSIX (among other things),
since the older terminal APIs can not accommodate the new speeds --
out o' bits. But this often also means wholesale conversion to POSIX
APIs. In general, just try adding -DPOSIX and then see what goes
wrong. Be wary of features disappearing: when _POSIX_SOURCE is
defined, all sorts of things that were perfectly OK before suddenly
become politically incorrect -- like reading modem signals, doing
hardware flow control, etc. POSIX was evidently not designed with
serial communication in mind!
Case in point: In UnixWare 7.0, #define'ing POSIX causes strictness
clauses in the header files to take effect. These prevent <sys/time.h>
from defining the timeval and timezone structs, which are needed for
all sorts of things (like select()). Thus, if we want the high serial
speeds, we have to circumvent the POSIX clauses.
Similarly in SCO OpenServer R5.0.4 where, again, we must use the POSIX
APIs to get at serial speeds higher than 38400, but then doing so
removes hardware flow control -- just when we need it most! In cases
like this, dirty tricks are the only recourse (search for SCO_OSR504
in [236]ckutio.c for examples).
For reasons like this, Unix implementations tend to be neither pure
AT&T nor pure BSD nor pure POSIX, but a mixture of two or more of
these, with "compatibility features" allowing different varieties of
programs to be built on the same computer. In general, Kermit tries
not to mix and match but to keep a consistent repertoire throughout.
However, there are certain Unix implementations that only work when
you mix and match. For example, the Silicon Graphics IRIX operating
system (prior to version 3.3) is an AT&T Unix but with a BSD file
system. The only way you can build Kermit successfully for this
configuration is to include -DSVR3 plus the special option -DLONGFN,
meaning "pretend I was built with -DBSDxx when it's time to compile
file-related code". See the "iris" makefile target.
9.1. Standards
[ [237]Top ] [ [238]Section Contents ] [ [239]Contents ] [ [240]Next ]
9.1.1. [241]POSIX
9.1.2. [242]ANSI C
9.1.3. [243]Other Standards
In edits 166-167 (1988-89), C-Kermit was heavily modified to try to
keep abreast of new standards while still remaining compatible with
old versions of C and Unix. There are two new standards of interest:
ANSI C (as described in Kernighan and Ritchie, "The C Programming
Language", Second Edition, Prentice Hall, 1988) and POSIX.1 (IEEE
Standard 1003.1 and ISO/IEC 9945-1, 1990, "Portable Operating System
Interface"). These two standards have nothing to do with each other:
you can build C-Kermit with a non-ANSI compiler for a POSIX system, or
for a non-POSIX system with with an ANSI compiler.
9.1.1. POSIX
POSIX.1 defines a repertoire of system functions and header files for
use by C language programs. Most notably, the ioctl() function is not
allowed in POSIX; all ioctl() functions have been replaced by
device-specific functions like tcsetattr(), tcsendbreak(), etc.
Computer systems that claim some degree of POSIX compliance have made
some attempt to put their header files in the right places and give
them the right names, and to provide system library functions with the
right names and calling conventions. Within the header files,
POSIX-compliant functions are supposed to be within #ifdef
_POSIX_SOURCE..#endif conditionals, and non-POSIX items are not within
these conditionals.
If Kermit is built with neither -D_POSIX_SOURCE nor -DPOSIX, the
functions and header files of the selected version of Unix (or VMS,
etc) are used according to the CFLAGS Kermit was built with.
If Kermit is built with -D_POSIX_SOURCE but not -DPOSIX, then one of
the -DBSD or -DATTSV flags (or one that implies them) must also be
defined, but it still uses only the POSIX features in the system
header files. This allows C-Kermit to be built on BSD or AT&T systems
that have some degree of POSIX compliance, but still use BSD or AT&T
specific features.
The dilimma is this: it is often necessary to define _POSIX_SOURCE to
get at new or modern features, such as high serial speeds and the APIs
to deal with them. But defining _POSIX_SOURCE also hides other APIs
that Kermit needs, for example the ones dealing with modem signals
(others are listed just below). Thus all sorts of hideous contortions
are often required to get a full set of features.
The POSIX standard does not define anything about uucp lockfiles.
"make posix" uses NO (repeat, NO) lockfile conventions. If your
POSIX-compliant Unix version uses a lockfile convention such as
HDBUUCP (see below), use the "posix" entry, but include the
appropriate lockfile option in your KFLAGS on the "make" command line,
for example:
make posix "KFLAGS=-DHDBUUCP"
POSIX.1 also lacks certain other features that Kermit needs. For
* There is no defined way for an application to do wildcard matching
of filenames. Kermit uses the inode in the directory structure,
but POSIX.1 does not include this concept. (Later POSIX revisions
include functions named (I think) glob() and fnmatch(), but these
functions are not yet in Kermit, and might not be appropriate in
any case.)
* There is no POSIX mechanism for sensing or controlling modem
signals, nor to enable RTS/CTS or other hardware flow control.
* There is no select() for multiplexing i/o, and therefore no
* There is no way to check if characters are waiting in a
communications device (or console) input buffer, short of trying
to read them -- no select(), ioctl(fd,FIONREAD,blah), rdchk(),
etc. This is bad for CONNECT mode and bad for sliding windows.
* No way to do a millisecond sleep (no nap(), usleep(), select(),
* There is no popen().
So at this point, there cannot be one single fully functional POSIX
form of C-Kermit unless it also has "extensions", as do Linux, QNX,
More on POSIX (quoting from a newsgroup posting by Dave Butenhof):
Standards tend to look at themselves as "enabling". So POSIX
standards say that, in order to use POSIX functions, a program must
define some macro that will put the development environment in
"POSIX mode". For the ancient POSIX 1003.1-1990, the symbol is
_POSIX_SOURCE. For recent revisions, it's _POSIX_C_SOURCE with an
appropriate value. POSIX 1003.1-1996 says that, to use its features
in a portable manner, you must define _POSIX_C_SOURCE=199506L
before including any header files.
But for Solaris, or Digital Unix, the picture is different. POSIX
is one important but small part of the universe. Yet POSIX
unconditionally and unambiguously REQUIRES that, when
_POSIX_C_SOURCE=199506L, ALL of the functions and definitions
required by the standard, and NO others (except in specific
restricted namespaces, specifically "_" followed by an uppercase
letter or "__" followed by a lowercase letter) shall be visible.
That kinda puts a cramp on BSD and SVID support, because those
require names that are not in the "protected" POSIX namespaces.
It's ILLEGAL to make those symbols visible, unless you've done
something else that's beyond the scope of POSIX to allow the system
to infer that you didn't really mean it.
In most cases, you should just compile, with no standards-related
macros defined. The system will make available every interface and
definition that isn't incompatible with the "main stream". There
may indeed be cases where two standards cross, and you really can't
use both together. But, in general, they play nicely together as
long as you don't do anything rash -- like telling the system that
it's not allowed to let them.
In the area of threads, both Solaris and Digital Unix support
incompatible thread APIs. We have POSIX and DCE, they have POSIX
and UI. The nasty areas are in the _r routines and in some aspects
of signal behavior. You cannot compile a single source file that
uses both semantics. That's life. It sounds as if Solaris defaults
to the UI variants, but allows you to define this
_POSIX_THREAD_SEMANTICS to get around it. We default to POSIX, and
allow you to define _PTHREAD_USE_D4 (automatically defined by the
cc "-threads" switch) to select the DCE thread variants. That
default, because you're operating outside of any individual
standard, is really just a marketing decision.
9.1.2. ANSI C
[ [244]Top ] [ [245]Contents ] [ [246]Section Contents ] [
[247]Subsection Contents ] [ [248]Next ] [ [249]Previous ]
The major difference between ANSI C and earlier C compilers is
function prototyping. ANSI C allows function arguments to be checked
for type agreement, and (when possible) type coercion in the event of
a mismatch. For this to work, functions and their arguments must be
declared before they are called. The form for function declarations is
different in ANSI C and non-ANSI C (ANSI C also accepts the earlier
form, but then does not do type checking).
As of edit 167, C-Kermit tries to take full advantage of ANSI C
features, especially function prototyping. This removes many bugs
introduced by differing data types used or returned by the same
functions on different computers. ANSI C features are automatically
enabled when the symbol __STDC__ is defined. Most ANSI C compilers,
such as GNU CC and the new DEC C compiler define this symbol
On the downside, ANSI C compilation increases the
administrative/bureacratic burden, spewing out countless unneeded
warnings about mismatched types, especially when we are dealing with
signed and unsigned characters, requiring casts everywhere to shut up
the mindless complaints -- there is no use for signed chars in Kermit
(or probably anywhere else). Some compilers, mercifully, include a
"treat all chars as unsigned" option, and when available it should be
used -- not only to stop the warnings, but also to avoid unhelpful
sign extension on high-bit characters.
To force use of ANSI C prototypes, include -DCK_ANSIC on the cc
command line. To disable the use of ANSI prototypes, include -DNOANSI.
9.1.3. Other Standards
[ [250]Top ] [ [251]Contents ] [ [252]Section Contents ] [
[253]Subsection Contents ] [ [254]Next ] [ [255]Previous ]
As the years go by, standards with-which-all-must-comply continue to
pile up: AES, XPG2, XPG3, XPG4, FIPS 151-2, successive generations of
POSIX, OSF/1, X/Open, Spec 1170, UNIX95, Open Group UNIX98, ISO/IEC
9945 parts 1-4, ISO 9899, 88Open, OS 99, Single Unix Specification
(SUS, [256]IEEE 1003.1-2001, not to mention "mature standards" like
V7, 4.2/4.3BSD, System V R3 and R4 (SVID2 and SVID3), 4.4BSD (the
basis for BSDI, OpenBSD, NetBSD, FreeBSD, Mac OS X etc), /usr/group,
plus assorted seismic pronouncements of the neverending series of
ephemeral corporate consortia, not to mention the libc-vs-glibc
turmoil in the Linux arena and who knows what else.
None of these standards simplifies life for portable applications like
C-Kermit -- each one is simply one more environment to support (or
circumvent, as in many cases these standards do more harm than good by
denying access to facilities we need, e.g. as noted in above in
9.2. Library Issues
[ [258]Top ] [ [259]Contents ] [ [260]Section Contents ] [
[261]Subsection Contents ] [ [262]Next ] [ [263]Previous ]
On most modern platforms, applications are -- and often must be --
dynamically linked. This has numerous advantages (smaller executables,
ability to patch a library and thereby patch all applications that use
it, etc), but also causes some headaches: most commonly, the library
ID built into the executable at link time does not match the ID of the
corresponding library on the target system, and so the loader refuses
to let the application run.
This problem only gets worse over time. In the Linux and *BSD world,
we also have totally different libraries (each with their own names
and numbering systems) that cover the same territory; for example,
curses vs ncurses, libc versus glibc. Combinations proliferate and any
given Unix computer might have any combination. For this reason it is
becoming increasingly difficult to produce a "Linux binary" for a
given architecture (e.g. PC or Alpha). There has to be a separate
binary for (at least) every combination of curses vs ncurses and libc
vs glibc.
In such cases, the best advice is for every user to build C-Kermit
from source code on the system where it will run. Too bad most
commercial Unix vendors have stopped including C compilers with the
operating system!
9.3. Unix File System Peculiarities
[ [264]Top ] [ [265]Contents ] [ [266]Section Contents ] [ [267]Next ]
[ [268]Previous ]
Normally, including a BSD, System-V, POSIX, or DIRENT flag in the make
entry selects the right file system code. But some versions of Unix
are inconsistent in this regard, and building in the normal way either
gives compiler or linker errors, or results in problems at runtime,
typically failure to properly expand wildcard file specifications when
you do something like "send *.*", or failure to recognize long
filenames, as in "send filewithaveryveryveryveryverylongname".
C-Kermit is supposed to know about all the various styles of Unix file
systems, but it has to be told which one to use when you build it,
usually in the makefile target CFLAGS as shown below, but you might
also have to add something like -I/usr/include/bsd to CFLAGS, or
something like -lbsd to LIBS.
C-Kermit gives you the following CFLAGS switches to adapt to your file
system's peculiarities:
-DDIRENT - #include <dirent.h>
-DSDIRENT - #include <sys/dirent.h>
-DNDIR - #include <ndir.h>
-DXNDIR - #include <sys/ndir.h>
-DRTU - #include "/usr/lib/ndir.h", only if NDIR and XNDIR not defined.
-DSYSUTIMH - #include <sys/utime.h> for setting file creation dates.
-DUTIMEH - #include <utime.h> for setting file creation dates.
(Note, RTU should only be used for Masscomp RTU systems, because it
also selects certain other RTU-specific features.)
If none of these is defined, then <sys/dir.h> is used. IMPORTANT: If
your system has the file /usr/include/dirent.h then be sure to add
-DDIRENT to your makefile target's CFLAGS. "dirent" should be used in
preference to any of the others, because it supports all the features
of your file system, and the others probably don't.
Having selected the appropriate directory header file, you might also
need to tell Kermit how to declare the routines and variables it needs
to read the directory. This happens most commonly on AT&T System-V
based UNIXes, particularly System V R3 and earlier, that provide long
file and directory names (longer than 14 characters). Examples include
certain releases of HP-UX, DIAB DNIX, older versions of Silicon
Graphics IRIX, and perhaps also MIPS. In this case, try adding
-DLONGFN to your makefile target.
Another problem child is <sys/file.h>. Most Unix C-Kermit versions
need to #include this file from within [269]ckufio.c and
[270]ckutio.c, but some not only do not need to include it, but MUST
not include it because (a) it doesn't exist, or (b) it has already
been included by some other header file and it doesn't protect itself
against multiple inclusion, or (c) some other reason that prevents
successful compilation. If you have compilation problems that seem to
stem from including this file, then add the following switch to CFLAGS
in your makefile target:
There are a few odd cases where <sys/file.h> must be included in one
of the cku[ft]io.c files, but not the other. In that case, add the
aforementioned switch, but go into the file that needs <sys/file.h>
and add something like this:
#ifdef XXX /* (where XXX is a symbol unique to your system) */
#undef NOFILEH
#endif /* XXX */
before the section that includes <sys/file.h>.
Kermit's SEND command expands wildcard characters "?" and "*" itself.
Before version 5A, commands like "send *" would send all regular
(non-directory) files, including "hidden files" (whose names start
with "."). In version 5A, the default behavior is to match like the
Bourne shell or the ls command, and not include files whose names
start with dot. Such files can still be sent if the dot is included
explicitly in the SEND command: "send .oofa, send .*". To change back
to the old way and let leading wildcard characters match dot files,
include the following in your CFLAGS:
(In C-Kermit 6.0, there is also a command to control this at runtime.)
Complaints about data-type mismatches:
* If you get compile-time complaints about data type mismatches for
process-ID related functions like getpid(), add -DPID_T=pid_t.
* If you get compile-time complaints about data type mismatches for
user ID related functions like getuid(), add -DUID_T=uid_t.
* If you get compile-time complaints about data type mismatches for
user-ID related functions like getgid(), add -DGID_T=gid_t.
* If you get compile-time complaints about data type mismatches for
getpwuid(), add -DPWID_T=uid_t (or whatever it should be).
File creation dates: C-Kermit attempts to set the creation date/time
of an incoming file according to the date/time given in the file's
attribute packet, if any. If you find that the dates are set
incorrectly, you might need to build Kermit with the -DSYSUTIMEH flag,
to tell it to include <sys/utime.h>. If that doesn't help, look at the
code in zstrdt() in [271]ckufio.c.
9.4. Hardware Flow Control
[ [272]Top ] [ [273]Contents ] [ [274]Section Contents ] [ [275]Next ]
[ [276]Previous ]
Hardware flow control is a problematic concept in many popular Unix
implementations. Often it is lacking altogether, and when available,
the application program interface (API) to it is inconsistent from
system to system. Here are some examples:
a. POSIX does not support hardware flow control.
b. RTS/CTS flow control support MIGHT be available for System V R3
and later if /usr/include/termiox.h exists (its successful
operation also depends on the device driver, and the device
itself, not to mention the cable, etc, actually supporting it). If
your SVR3-or-later Unix system does have this file, add:
to your CFLAGS. If the file is in /usr/include/sys instead, add:
Note that the presence of this file does not guarantee that
RTS/CTS will actually work -- that depends on the device-driver
implementation (reportedly, many Unix versions treat
hardware-flow-control related ioctl's as no-ops).
c. Search ("grep -i") through /usr/include/*.h and
/usr/include/sys/*.h for RTS or CTS and see what turns up. For
example, in SunOS 4.x we find "CRTSCTS". Figuring out how to use
it is another question entirely! In IBM AIX RS/6000 3.x, we have
to "add" a new "line discipline" (and you won't find uppercase RTS
or CTS symbols in the header files).
d. NeXTSTEP and IRIX, and possibly others, support hardware flow
control, but do not furnish an API to control it, and thus on
these systems Kermit has no command to select it -- instead, a
special device name must be used. (NeXTSTEP: /dev/cufa instead of
/dev/cua; IRIX: /dev/ttyf00)
See the routine tthflow() in [277]ckutio.c for details. If you find
that your system offers hardware flow control selection under program
control, you can add this capability to C-Kermit as follows:
a. See if it agrees with one of the methods already used in
tthflow(). if not, add new code, appropriately #ifdef'd.
b. Add -DCK_RTSCTS to the compiler CFLAGS in your makefile target or
define this symbol within the appropriate #ifdefs in
To illustrate the difficulties with RTS/CTS, here is a tale from Jamie
Watson <>, who added the RTS/CTS code for the RS/6000,
about his attempts to do the same for DEC ULTRIX:
"The number and type of hardware signals available to/from a serial
port vary between different machines and different types of serial
interfaces on each machine. This means that, for example, there are
virtually no hardware signals in or out available on the DECsystem
3000/3100 series; on the DECsystem 5000/2xx series all modem
signals in/out are present on both built-in serial ports; on the
DECsystem 5100 some ports have all signals and some only have some;
and so on... It looks to me as if this pretty well rules out any
attempt to use hardware flow control on these platforms, even if we
could figure out how to do it. The confusion on the user level
about whether or not it should work for any given platform or port
would be tremendous. And then it isn't clear how to use the
hardware signals even in the cases where the device supports them."
9.5. Terminal Speeds
[ [279]Top ] [ [280]Contents ] [ [281]Section Contents ] [ [282]Next ]
[ [283]Previous ]
The allowable speeds for the SET SPEED command are defined in
[284]ckcdeb.h. If your system supports speeds that are not listed in
"set speed ?", you can add definitions for them to ckcdeb.h.
Then if the speed you are adding is one that was never used before in
Kermit, such as 921600, you'll also need to add the appropriate
keywords to spdtab[] in [285]ckuus3.c, and the corresponding case to
ttsspd() in [286]ckutio.c.
9.6. Millisecond Sleeps
[ [287]Top ] [ [288]Contents ] [ [289]Section Contents ] [ [290]Next ]
[ [291]Previous ]
There is no standard for millisecond sleeps, but at least five
different functions have appeared in various Unix versions that can be
used for this purpose: nap() (mostly in System V), usleep() (found at
least in SunOS and NeXT OS), select() (found in 4.2BSD and later, and
part of any TCP/IP sockets library), nanosleep(), and sginap(). If you
have any of these available, pick one (in this order of preference, if
you have more than one):
-DSELECT: Include this in CFLAGS if your system has the select() function.
-DNAP: Include this in CFLAGS if your system has the nap() function.
-USLEEP: Include this in CFLAGS if your system has the usleep() function.
NOTE: The nap() function is assumed to be a function that puts the
process to sleep for the given number of milliseconds. If your
system's nap() function does something else or uses some other units
of time (like the NCR Tower 32, which uses clock-ticks), do not
include -DNAP.
Reportedly, all versions of System V R4 for Intel-based computers, and
possibly also SVR3.2, include nap() as a kernel call, but it's not in
the library. To include code to use it via syscall(3112,x), without
having to include Xenix compatibility features, include the following
compile-time option:
9.7. Nondestructive Input Buffer Peeking
[ [292]Top ] [ [293]Contents ] [ [294]Section Contents ] [ [295]Next ]
[ [296]Previous ]
Some AT&T Unix versions have no way to check if input is waiting on a
tty device, but this is a very important feature for Kermit. Without
it, sliding windows might not work very well (or at all), and you also
have to type your escape character to get Kermit's attention in order
to interrupt a local-mode file transfer. If your system offers an
FIONREAD ioctl, the build procedure should pick that up automatically
and use it, which is ideal.
If your system lacks FIONREAD but has a select() function, this can be
used instead. If the build procedure fails to include it (SHOW
FEATURES will list SELECT), then you can add it to your CFLAGS:
Conversely, if the build procedure tries to use select() when it
really is not there, add:
Note: select() is not part of System V nor of POSIX, but it has been
added to various System-V- and POSIX-based systems as an extension.
Some System-V variations (SCO Xenix/UNIX/ODT and DIAB DNIX) include a
rdchk() function that can be used for buffer peeking. It returns 0 if
no characters are waiting and 1 if characters are waiting (but unlike
FIONREAD, it does not tell the actual number). If your system has
rdchk(), add:
-DRDCHK: Include this in CFLAGS if your system has the rdchk() function.
Otherwise, if your version of Unix has the poll() function (and the
/usr/include/poll.h file) -- which appears to be a standard part of
System V going back to at least SVR3, include:
9.8. Other System-Dependent Features
[ [297]Top ] [ [298]Contents ] [ [299]Section Contents ] [ [300]Next ]
[ [301]Previous ]
Systems with <termios.h> might have the symbol IEXTEN defined. This is
used to turn "extended features" in the tty device driver on and off,
such as Ctrl-O to toggle output flushing, Ctrl-V to quote input
characters, etc.
In most Unix implementations, it should be turned off during Kermit
operation, so if [302]ckutio.c finds this symbol, it uses it. This is
necessary, at least, on BSDI. On some systems, however, IEXTEN is
either misdefined or misimplemented. The symptom is that CR, when
typed to the command processor, is echoed as LF, rather than CRLF.
This happens (at least) on Convex/OS 9.1. The solution is to add the
following symbol to the makefile target's CFLACS:
However, in at least one Unix implementation, QNX 4.21, IEXTEN must be
set before hardware flow control can be used.
In edits 177 and earlier, workstation users noticed a "slow screen
writing" phenomenon during interactive command parsing. This was
traced to a setbuf() call in [303]ckutio.c that made console (stdout)
writes unbuffered. This setbuf() call has been there forever, and
could not be removed without some risk. Kermit's operation was tested
on the NeXT in edit 178 with the setbuf() call removed, and the
slow-writing symptom was cured, and everything else (command parsing,
proper wakeup on ?, ESC, Ctrl-U, and other editing characters,
terminal emulation, remote-mode and local-mode file transfer, etc)
seemed to work as well as or better than before. In subsequent edits,
this change was made to many other versions too, with no apparent ill
effects. To remove the setbuf() call for your version of Kermit, add:
Later reports indicate that adding -DNOSETBUF has other beneficial
effects, like cutting down on swapping when Kermit is run on
workstations with small memories. But BEWARE: on certain small Unix
systems, notably the AT&T 6300 and 3B1 (the very same ones that
benefit from NOSETBUF), NOSETBUF seems to conflict with CK_CURSES. The
program builds and runs OK, but after once using the curses display,
echoing is messed up. In this case, we use a System-V specific
variation in the curses code, using newterm() to prevent System V from
altering the buffering. See makefile entries for AT&T 6300 and 3B1.
The Unix version of C-Kermit includes code to switch to file
descriptor zero (stdin) for remote-mode file transfer. This code is
necessary to prevent Kermit from giving the impression that it is
"idle" during file transfers, which, at some sites, can result in the
job being logged out in the middle of an active file transfer by
idle-job monitors.
However, this feature can interfere with certain setups; for example,
there is a package which substitutes a pty/tty pair for /dev/tty and
sets file descriptor 0 to be read-only, preventing Kermit from sending
packets. Or... When a Unix shell is invoked under the PICK
environment, file descriptor 0 is inoperative.
To remove this feature and allow Kermit to work in such environments,
add the compile-time option:
On some versions of Unix, earlier releases of C-Kermit were reported
to render a tty device unusable after a hangup operation. Examples
include IBM AIX on the RT PC and RS/6000. A typical symptom of this
phenomenon is that the DIAL command doesn't work, but CONNECTing to
the device and dialing manually do work. A further test is to SET DIAL
HANGUP OFF, which should make dialing work once by skipping the
pre-dial hangup. However, after the connection is broken, it can't be
used any more: subsequent attempts to DIAL the same device don't work.
The cure is usually to close and reopen the device as part of the
hangup operation. To do this, include the following compile-time
Similarly, there is a section of code in ttopen(), which does another
close(open()) to force the O_NDELAY mode change. On some systems, the
close(open()) is required to make the mode change take effect, and
apparently on most others it does no harm. But reportedly on at least
one System V R4 implementation, and on SCO Xenix 3.2, the
close(open()) operation hangs if the device lacks carrier, EVEN THOUGH
the CLOCAL characteristic has just been set to avoid this very
problem. If this happens to you, add this to your CFLAGS:
or, equivalently, in your KFLAGS on the make command line. It stands
for NO Close(Open()) To Force Mode Change.
C-Kermit renames files when you give a RENAME command and also
according to the current SET FILE COLLISION option when receiving
files. The normal Unix way to rename a file is via two system calls:
link() and unlink(). But this leaves open a window of vulnerability.
Some Unix systems also offer an atomic rename(oldname,newname)
function. If your version of Unix has this function, add the following
to your CFLAGS:
C-Kermit predefines the RENAME for several Unix versions in
[304]ckcdeb.h (SVR4, SUNOS41, BSD44, AIXRS, etc). You can tell if
rename() is being used if the SHOW FEATURES command includes RENAME in
the compiler options list. If the predefined RENAME symbol causes
trouble, then add NORENAME to your CFLAGS. Trouble includes:
a. Linker complains that _rename is an unresolved symbol.
b. Linking works, but Kermit's RENAME command doesn't work (which
happens because older versions of rename() might have their
arguments reversed).
If rename() is not used, then Kermit uses link()/unlink(), which is
equivalent except it is not atomic: there is a tiny interval in which
some other process might "do something" to one of the files or links.
Some Unix systems (Olivetti X/OS, Amdahl UTS/V, ICL SVR3, etc) define
the S_ISREG and S_ISDIR macros incorrectly. This is compensated for
automatically in [305]ckufio.c. Other systems might have this same
problem. If you get a compile-time error message regarding S_ISREG
and/or S_ISDIR, add the following to your CFLAGS:
Finally, here's a symbol you should NEVER define:
It's used for commenting out blocks of code. If for some reason you
find that your compiler has COMMENT defined, then add -UCOMMENT to
CFLAGS or KFLAGS! Similarly, some header files have been known to
define COMMENT, in which case you must add "#undef COMMENT" to each
C-Kermit source module, after all the #includes.
9.9. Terminal Interruption
[ [306]Top ] [ [307]Contents ] [ [308]Section Contents ] [ [309]Next ]
[ [310]Previous ]
When C-Kermit enters interactive command mode, it sets a Control-C
(terminal keyboard interrupt = SIGINT) trap to allow it to return to
the command prompt whenever the user types Control-C (or whatever is
assigned to be the interrupt character). This is implemented using
setjmp() and longjmp(). On some systems, depending on the machine
architecture and C compiler and who knows what else, you might get
"Memory fault (coredump)" or "longjmp botch" instead of the desired
effect (this should not happen in 5A(190) and later). In that case,
add -DNOCCTRAP to your CFLAGS and rebuild the program.
Job control -- the ability to "suspend" C-Kermit on a Unix system by
typing the "susp" character (normally Ctrl-Z) and then resume
execution later (with the "fg" command) -- is a tricky business.
C-Kermit must trap suspend signals so it can put the terminal back
into normal mode when you suspend it (Kermit puts the terminal into
various strange modes during interactive command parsing, CONNECT, and
file transfer). Supporting code is compiled into C-Kermit
automatically if <signal.h> includes a definition for the SIGTSTP
signal. HOWEVER... some systems define this signal without supporting
job control correctly. You can build Kermit to ignore SIGTSTP signals
by including the -DNOJC option in CFLAGS. (You can also do this at
runtime by giving the command SET SUSPEND OFF.)
NOTE: As of version 5A(190), C-Kermit makes another safety check.
Even if job control is available in the operating system (according
to the numerous checks made in congm()), it will still disable the
catching of SIGTSTP signals if SIGTSTP was set to SIG_IGN at the
time C-Kermit was started.
System V R3 and earlier systems normally do not support job control.
If you have an SVR3 system that does, include the following option in
your CFLAGS:
On systems that correctly implement POSIX signal handling, signals can
be handled more reliably than in Bell, Berkeley, or AT&T Unixes. On
systems (such as QNX) that are "strictly POSIX", POSIX signal handling
*must* be used, otherwise no signal will work more than once. If you
have POSIX-based system and you find that your version of Kermit
responds to Ctrl-C (SIGINT) or Ctrl-Z (SIGTSTP) only once, then you
should add the following option to your CFLAGS:
But be careful; some POSIX implementations, notably 4.4BSD, include
POSIX signal handling symbols and functions as "stubs" only, which do
nothing. Look in <signal.h> for sigsetjmp and siglongjmp and read the
[ [311]Top ] [ [312]Contents ] [ [313]Next ] [ [314]Previous ]
NOTE: Red Hat Linux 7.2 and later include a new API that allows
serial-port arbitration by non-setuid/gid programs. This API has
not yet been added to C-Kermit. If C-Kermit is to be used for
dialing out on Red Hat 7.2 or later, it must still be installed as
described in this section and the next.
The short version:
In order for C-Kermit to be able to dial out from your Unix
computer, you need to give it the same owner, group, and
permissions as your other dialout programs, such as cu, tip,
minicom, uucp, seyon, etc.
The long version:
Make sure your dialout line is correctly configured for dialing out
(as opposed to login). The method for doing this is different for each
kind of Unix. Consult your system documentation for configuring lines
for dialing out (for example, Sun SPARCstation IPC users should read
the section "Setting up Modem Software" in the Desktop SPARC Sun
System and Network Manager's Guide, or the Terminals and Modems
section of the HP manual, "Configuring HP-UX for Peripherals" (e.g.
/usr/sbin/sam => Peripheral Devices => Terminals and Modems => Add
Unlike most other multiuser, multitasking operating systems, Unix
allows multiple users to access the same serial device at the same
time, even though there is no earthly reason why two users should do
this. When they do, user A will read some of the incoming characters,
and user B will read the others. In all likelihood, neither user will
see them all. Furthermore, User B can hang up User A's call, etc.
Rather than change Unix to enforce exclusive access to serial devices
such as ttys, Unix developers chose instead to use a "lock file". Any
process that wants to open a tty device should first check to see if a
file of a certain name exists, and if so, not to open the device. If
the file does not exist, the process creates the file and then opens
the device. When the process closes the device, it destroys the
lockfile. This procedure was originated for use with Unix's UUCP, CU,
and TIP programs, and so these lockfiles are commonly called "UUCP
lockfiles" (UUCP = Unix-to-Unix Copy Program).
As you can imagine, this method is riddled with pitfalls:
* If a process does not observe the prevailing lockfile convention,
then it can interfere with other "polite" processes. And in fact,
very few Unix applications or commands handle lockfiles at all; an
original design goal of Unix was that "everything is a file", and
countless utilities operate on files directly (by opening them) or
indirectly through redirection of standard i/o, without creating
or looking for lockfiles.
* If a process crashes while it has the device open, the lockfile is
left behind, preventing further processes from using the device.
* Various versions of Unix use different names for the lockfiles,
put them in different directories, with different owners and
groups and permissions, and specify their contents differently.
* On a given platform, the lockfile conventions may change from one
Unix release to the next (for example, SunOS 4.0 to 4.1) or, in
the case of Linux, across different distributions.
* The same tty device might have more than one name, and most
lockfile conventions don't allow for this. Similarly for symbolic
In an attempt to address the problem of "stale" lockfiles, most UUCP
implementations put the PID (Process ID) of the creating process in
the lockfile. Thus, another process that wants to open the
corresponding device can check not only for the lockfile itself, but
also can check the PID for validity. But this doesn't work well
* PIDs are stored in diverse formats that change with every new
release (short, integer, long, or string in any of various
formats). If the reading program does not follow the same
convention as the writing program, it can diagnose a valid PID to
be invalid, and therefore not honor the lock.
* PIDs recycle. If the lockfile was created by PID 1234, which later
crashed without removing the lockfile, and then a new process 1234
exists a the time the lockfile is checked, the lockfile will be
improperly taken as valid, and access to the device denied
Several techniques address the problem of multiple names for the same
* Multiple lockfiles. For example, if the user opens a device
through a symlink, a lockfile is created for both the symlink name
and the true name (obtained from readlink()). However, when
multiple drivers are installed for the same device (e.g. /dev/cua,
/dev/cufa, etc), this approach won't work unless all applications
*know* all the different names for the same device and make
lockfiles for all of them, which is obviously not practical.
* Lockfiles whose names are not based on the device name. These
lockfiles generally have names like LK.inode/major/minor, where
inode, major, and minor are numbers, which will always be the same
for any physical device, no matter what its name. This form of
lockfile is used in System V R4 and its derivatives, such as
Solaris, UnixWare, etc. If lockfiles must be used (as opposed to,
say, kernel-based locks), this would seem to be the most effective
Most versions of Unix were not designed to accommodate third-party
communications software; thus vendors of these Unix products feel no
compunction about changing lockfile conventions from release to
release, since they also change their versions of the cu, uucp, tip,
etc, programs at the same time to match. And since the source code to
these programs might not be published, it is difficult for makers of
third-party products like C-Kermit to find out what the new
conventions are. It also forces release of new versions of C-Kermit
whenever the OS vendor makes a change like this.
Some Unix vendors have taken a small step to simplify communications
application development for their products: the inclusion of lockfile
routines in the standard system C runtime libraries to shield the
application from the details of lockfile management (IBM AIX is an
example). When such routines are used, communications applications do
not need modification when lockfile conventions change (although they
will need recompiling if the routines are statically linked into the
application). In the AIX example, the simple function calls ttylock(),
ttyunlock(), and ttylocked() replace hundreds of lines of ugly code in
C-Kermit that attempts to keep pace with every release of every Unix
product over the last 20 years. Inclusion of ttylock() code occurs
is included in the CFLAGS.
If such routines are available, they should be used. The rest of this
section applies when they are not.
To fit in with UUCP and other Unix-based communication software,
C-Kermit must have the same idea as your system's uucp, cu, and tip
programs about what the UUCP lock directory is called, what the
lockfile itself is called, and what its contents should be. In most
cases, C-Kermit preprocessor flags create the appropriate
configuration at compile time if the appropriate makefile target was
used (see [315]ckutio.c). The following CFLAGS options can be used to
override the built-in configuration:
Tells Kermit that the UUCP lock directory is
Tells Kermit to use the BSD 4.3 acucntrl() program to turn off
getty (login) on the line before using it, and restore getty
when done.
Include this if your system uses Honey DanBer UUCP, in which
the lockfile directory and format are relatively standardized.
Gives the lock directory name explicitly. The triple quoting is
necessary. For example:
CFLAGS= -DBSD4 -DLOCK_DIR=\\\"/usr/local/locks\\\" -DNODEBUG
(NOTE: The triple quoting assumes this is a "top-level" make
entry, and not a make entry that calls another one.)
-DLFDEVNO The lockfile name uses the tty device inode and major and
numbers:, as in Sys V R4, e.g. LK.035.044.008.
When the LK.inode.major.minor form is used, a single lockfile is
enough. Otherwise, a single lockfile rarely suffices. For example, in
Linux, it is common to have a /dev/modem symbolic link to an actual
dialout device, like /dev/cua0 or /dev/ttyS0, whose purpose is to hide
the details of the actual driver from the user. So if one user opens
/dev/modem, a lockfile called LCK..modem is created, which does not
prevent another user from simulataneously opening the same device by
its real name.
On SCO Unix platforms, we have a slightly different problem: the same
device is, by convention, known by "lowercase" and "uppercase" names,
depending on whether it has modem control. So by convention,
communications programs are supposed to create the lockfiles based on
the lowercase name. But some programs don't follow this convention. In
HP-UX, we have several different names for each serial device. And so
For this reason, on platforms where the LK.inode.major.minor form is
not used, C-Kermit also creates a secondary lockfile (which is simply
a link to the first) if:
a. The given device name is a symbolic link. The secondary link is
based on the device's real name.
b. On SCO: The device name is not a symbolic link, but it contains
uppercase letters. The primary link is based on the lowercase
name; the secondary link is based on the name that was given.
c. On HP-UX: The device name starts with "cu". The primary link is
based on the name that was given; the secondary link is based on
the corresponding "ttyd" device, e.g. "LCK..cua0p0" and
NOTE: symlinks are not handled in HP-UX.
Honey DanBer (HDB) UUCP, which is becoming increasingly popular, has
two characteristics:
a. Lockfiles are kept in /usr/spool/locks/ (usually).
b. A lockfile contains the process id (pid) in ASCII, rather than as
an int.
Non-HDB selections assume the lockfile contains the pid in int form
(or, more precisely, in PID_T form, where PID_T is either int or
pid_t, depending on your system's C library and header files). (b), by
the way, is subject to interpretation: the numeric ASCII string may or
may not be terminated by a newline, it may or may not have leading
spaces (or zeros), and the number of leading spaces or zeros can
differ, and the differences can be significant.
Even if you build the program with the right lockfile option, you can
still have problems when you try to open the device. Here are the
error messages you can get from SET LINE, and what they mean:
a. "Timed out, no carrier." This one is not related to lockfiles. It
means that you have SET CARRIER ON xx, where xx is the number of
seconds to wait for carrier, and carrier did not appear within xx
seconds. Solution: SET CARRIER AUTO or OFF.
b. "Sorry, access to lock denied." Kermit has been configured to use
lockfiles, but (a)the lockfile directory is write-protected
against you, or (b) it does not exist. The "access to lock denied"
message will tell you the reason. If the directory does not exist,
check to make sure Kermit is using the right name. Just because
version n of your Unix used a certain lockfile directory is no
gurantee that version n.1 does not use a different one.
Workaround: ask the system administrator to install a symbolic
link from the old name to the new name. Other solutions: (see
c. "Sorry, access to tty device denied." The tty device that you
specified in your SET LINE command is read/write protected against
you. Solution: (see below)
d. "Sorry, device is in use." The tty device you have specified is
currently being used by another user. A prefatory message gives
you an "ls -l" listing of the lockfile, which should show the
username of the person who created it, plus a message "pid = nnn"
to show you the process id of the user's program. Solutions: try
another device, wait until the other user is finished, ask the
other user to hurry up, or ask the system manager for help.
e. "Sorry, can't open connection: reason". The device cannot be
opened for some other reason, which is listed.
f. "sh: /usr/lib/uucp/acucntrl: not found". This means your Kermit
program was built with the -DACUCNTRL switch, but your computer
system does not have the BSD 4.3 acucntrl program. Solution:
install the acucntrl program if you have it, or rebuild Kermit
without the -DACUCNTRL switch.
There are two solutions for problems (b) and (c), both of which
involve intervention by your Unix system administrator (superuser):
a. Have the superuser change the permission of the lockfile directory
and to the tty devices so that everyone on the system has
read/write permission.
su% chmod 777 /usr/spool/locks (or whatever the path is)
su% chmod 666 /dev/ttyXX
One risk here is that people can write lots of junk into the
lockfile directory, delete other people's files in the lockfile
directory, and intercept other people's data as it goes in and out
of the tty device. The major danger here would be intercepting a
privileged password. Of course, any user could write a short,
ordinary, unprivileged program to do exactly the same thing if the
tty device was world read/writeable. The other risk as that
telephone calls are not controlled -- anybody on your system can
make them, without having to belong to any particular group, and
this could run up your phone bill.
b. Use groups to regulate access. Normally the lockfile directory and
and the dialout devices will have the same group (such as uucp).
If so, then put everybody who's allowed to dial out into that
group, and make sure that the lockfile directory and the tty
devices have group read AND write permission. Example:
su% chmod 770 /usr/spool/locks (or whatever the path is)
su% chmod 660 /dev/ttyXX
User whatever tool is available on your platform to add users to
the appropropriate group (e.g. edit the /etc/group file).
c. Have the superuser change Kermit to run setuid and/or setgid to
the owner and/or group of the lockfile directory and the tty
devices if necessary), typically uucp (see [316]next section), but
NOT root. Example:
su% chown uucp kermit - or - chgrp uucp kermit
su% chmod u+s kermit (setuid) - or - chmod g+s kermit (setgid)
and then make sure the lockfile directory, and the tty devices,
have owner (setuid) and/or group (setgid) write permission. For
su% chmod o+rwx /usr/spool/uucp
su% chown uucp /dev/ttyXX ; chmod 600 /dev/ttyXX
In some cases, the owner and group must be distinct; the key point
is that read/write access is required to both the UUCP lockfile
directory and the tty itself.
If you make C-Kermit setuid or setgid to root, it refuses to run:
Fatal: C-Kermit setuid to root!
crw-r----- 1 uucp uucp 5, 67 Feb 11 06:23 /dev/cua3
drwxrwxr-x 3 root uucp 1024 Feb 11 06:22 /var/lock
requires suid uucp to get read/write access on /dev/cua3 and sgid to
get read/write access on /var/lock (since you can't set Kermit's uid
or gid to root).
The reason Kermit can't be setuid or setgid to root has to do with
the fact that some Unix OS's can't switch user or group IDs in that
case. Unfortunately, the prohibition against making Kermit setuid
or setgid to root means that Unix C-Kermit can't be used to make
rlogin connections by non-root users. (The rlogin port is
privileged, which is why the regular rlogin command is setuid root
-- which is safe because the rlogin program never has to create or
access files like Kermit does.)
For the lockfile mechanism to achieve its desired purpose --
prevention of access to the same tty device by more than one process
at a time -- ALL programs on a given computer that open, read or
write, and close tty devices must use the SAME lockfile conventions.
Unfortunately, this is often not the case. Here is a typical example
of how this can go wrong: In SunOS 4.0 and earler, the lockfile
directory was /usr/spool/uucp; in 4.1 it was changed to
/var/spool/locks in the quest for political correctness. Consequently,
any third-party programs (such as C-Kermit) that were not modified to
account for this change, recompiled, and reinstalled, did not use the
same lockfiles as uucp, tip, etc, and so the entire purpose of the
lockfile is defeated.
What if your Unix system does not have UUCP installed? For example,
you have a Unix workstation, and you do not use uucp, cu, or tip, or
UUCP was not even supplied with your version of Unix (QNX is an
example). In this case, you have two choices:
a. If there may be more than one person running Kermit at the same
time, competing for the same tty device, then create a special
lockfile directory just for Kermit, for example,
/usr/spool/kermit, and make sure you have read/write access to it.
Then add the following to your makefile target CFLAGS, as shown
b. If you are the only user on your workstation, and no other
processes will ever be competing with Kermit for the dialout tty
device, then add -DNOUUCP to your makefile target's CFLAGS and
rebuild Kermit.
[ [317]Top ] [ [318]Contents ] [ [319]Next ] [ [320]Previous ]
Even if you don't intend to run C-Kermit setuid, somebody else might
come along and chown and chmod it after it has been built. You should
be sure that it is built correctly to run setuid on your system. For
POSIX and AT&T Unix based versions, you don't have to do anything
For 4.2 and 4.3 BSD-based Unix versions, you normally need not add
anything special to the makefile. The program assumes that the
setreuid() and setregid() functions are available, without which we
cannot switch back and forth between real and effective uids. If
"make" complains that _setreuid or _setregid is/are not defined, add
-DNOSETREU to CFLAGS. In this case it is very likely (but not certain)
that you cannot protect ttys and lockfiles against people and have
them run Kermit setuid.
If make does not complain about this, you should find out whether your
BSD version (4.3 or other systems like SunOS 4.x that claim to include
BSD 4.3 compatibility) includes the saved-setuid feature (see long
notes under edit 146 in ckc178.upd). If it does, then add -DSAVEDUID
IMPORTANT NOTE: Most Unix system documentation will not give you
the required information. To determine whether your Unix system
supplies the the saved-original-effective-user/group-id feature,
use the ckuuid.c program. Read and follow the instructions in the
comments at the beginning.
C-Kermit for 4.4BSD-based systems automatically use sete[ug]id(). See
If you have a version of Unix that is not BSD-based, but which
supplies the setreuid() and setregid() functions, and these are the
only way to switch between real and effective uid, add -DSETREUID to
your makefile target.
WARNING: There are two calls to access() in [322]ckufio.c, by which
Kermit checks to see if it can create an output file. These calls
will not work correctly when (a)you have installed C-Kermit setuid
or setgid on a BSD-based Unix system, and (b) the
saved-original-effective-uid/gid feature is not present, and (c)
the access() function always checks what it believes to be the real
ID rather than the effective ID. This is the case, for example, in
Olivetti X/OS and in NeXTSTEP. In such cases, you can force correct
operation of access() calls by defining the symbol SW_ACC_ID at
compile time in CFLAGS.
If you have a version of Unix that does not allow a process to switch
back and forth between its effective and real user and group ids
multiple times, you probably should not attempt to run Kermit setuid,
because once having given up its effective uid or gid (which it must
do in order to transfer files, fork a shell, etc) it can never get it
back, and so it can not use the original effective uid or gid to
create or delete uucp lockfiles. In this case, you'll either have to
set the permissions on your lockfile directory to make them publicly
read/writable, or dispense with locking altogether.
MORAL: Are you thoroughly sickened and/or frightened by all that you
have just read? You should be. What is the real answer? Simple. Serial
devices -- such as ttys and magnetic tapes -- in Unix should be opened
with exclusive access only, enforced by the Unix kernel. Shared access
has no conceivable purpose, legitimate or otherwise, except by
privileged system programs such as getty. The original design dates
from the late 1960s, when Unix was developed for laboratory use under
a philosophy of trust by people within shouting distance of each other
-- but even then, no useful purpose was served by this particular form
of openness; it was probably more of a political statement. Since the
emergence of Unix from the laboratory into the commercial market, we
have seen every vestige of openness -- but this one -- stripped away.
I'd like to see some influential Unix maker take the bold step of
making the simple kernel change required to enforce exclusive access
to serial devices. (Well, perhaps not so simple when bidirectionality
must also be a goal -- but then other OS's like VMS solved this
problem decades ago.)
[ [323]Top ] [ [324]Contents ] [ [325]Next ] [ [326]Previous ]
On desktop workstations that are used by only the user at the console
keyboard, C-Kermit is always used in local mode. But as delivered,
C-Kermit runs in remote mode by default. To put it in local mode at
startup, you can put a SET LINE command in your .mykermrc.
You can also build C-Kermit to start up in local mode by default. To
do this, include the following in the CFLAGS in your makefile target:
where ttyxx is the name of the device you will be using for
communications. Presently there is no way of setting the default modem
type at compile time, so use this option only for direct lines.
C-Kermit does not work well on certain workstations if it is not run
from within a terminal window. For example, you cannot start C-Kermit
on a NeXT by launching it directly from NeXTstep. Similarly for Sun
workstations in the Open Windows environment. Run Kermit in a terminal
[ [327]Top ] [ [328]Contents ] [ [329]Next ] [ [330]Previous ]
See the "beware file",
[331]ckubwr.txt, for hints about runtime misbehavior. This section
lists some runtime problems that can be cured by rebuilding C-Kermit.
The program starts, but there is no prompt, and certain operations
don't work (you see error messages like "Kermit command error in
background execution"). This is because Kermit thinks it is running in
the background. See conbgt() in [332]ckutio.c. Try rebuilding Kermit
added to your CFLAGS. If that doesn't help, find out the actual data
type for pids (look in types.h or similar file) and use it in place of
"pid_t", for example:
Unexplainable and inappropriate error messages ("Sockets not supported
on this device", etc) have been traced in at least one case to a lack
of agreement between the system header files and the actual kernel.
This happened because the GNU C compiler (gcc) was being used. gcc
wants to have ANSI-C-compliant header files, and so part of the
installation procedure for gcc is (or was) to run a shell script
called "fixincludes", which translates the system's header files into
a separate set of headers that gcc likes. So far so good. Later, a new
version of the operating system is installed and nobody remembers to
run fixincludes again. From that point, any program compiled with gcc
that makes use of header files (particularly ioctl.h) is very likely
to misbehave. Solution: run fixincludes again, or use your system's
regular C compiler, libraries, and header files instead of gcc.
[ [333]Top ] [ [334]Contents ] [ [335]Next ] [ [336]Previous ]
If C-Kermit constitently dumps core at the beginning of a file
transfer, look in SHOW FEATURES for CKREALPATH. If found, rebuild with
-DNOREALPATH and see if that fixes the problem (some UNIXes have
realpath() but it doesn't work).
Total failure of the Kermit program can occur because of bad memory
references, bad system calls, or problems with dynamic memory
allocation. First, try to reproduce the problem with debugging turned
on: run Kermit with the -d command-line option (for example, "wermit
-d") and then examine the resulting debug.log file. The last entry
should be in the vicinity of the crash. In VMS, a crash automatically
produces a "stack dump" which shows the routine where the crash
occurs. In some versions of Unix, you can get a stack dump with "adb"
-- just type "adb wermit core" and then give the command "$c", then
Ctrl-D to quit (note: replace "wermit" by "kermit" or by the full
pathname of the executable that crashed if it is not in the current
directory). Or use gdb to get a backtrace, etc.
In edit 186, one implementation, UNISYS 5000/95 built with "make
sys5r3", has been reported to run out of memory very quickly (e.g.
while executing a short initialization file that contains a SET DIAL
DIRECTORY command). Debug logs show that malloc calls are failing,
reason unknown. For this and any other implementation that gives error
messages about "malloc failure" or "memory allocation failure",
rebuild the program *without* the -DDYNAMIC CFLAGS definition, for
make sys5r3 KFLAGS=-UDYNAMIC
As of edit 169, C-Kermit includes a malloc() debugging package which
you may link with the Kermit program to catch runtime malloc errors.
See the makefile entries for sunos41md and nextmd for examples of how
to select malloc debugging. Once you have linked Kermit with the
malloc debugger, it will halt with an informative message if a
malloc-related error occurs and, if possible, dump core. For this
reason, malloc-debugging versions of Kermit should be built without
the "-s" link option (which removes symbols, preventing analysis of
the core dump). You have several ways to track down the malloc error:
Analyze the core dump with adb. Or reproduce the problem with "log
debug" and then look at the code around the last debug.log entry. If
you have gcc, build the program with "-g" added to CFLAGS and then
debug it with gdb, e.g.
gdb wermit
break main
.. set other breakpoints or watchpoints
Watchpoints are especially useful for finding memory leaks, but they
make the program run about a thousand times slower than usual, so
don't set them until the last possible moment. When a watchpoint is
hit, you can use the "where" command to find out which C-Kermit source
statement triggered it.
If you have the Pure Software Inc "Purify" product, see the sunos41cp
makefile entry for an example of how to use it to debug C-Kermit.
[ [337]Top ] [ [338]Contents ] [ [339]Next ] [ [340]Previous ]
"Syslogging" means recording selected in the system log via the Unix
syslog() facility, which is available in most Unix versions.
Syslogging is not done unless C-Kermit is started with:
on the command-line, where n is a number greater than 0 to indicate
the level of syslogging. See [341]Section 4.2 of the [342]IKSD
Administrator's Guide for details.
Obviously you can't depend on users to include --syslog:3 (or
whatever) on the command line every time they start C-Kermit, so if
you want certain kinds of records to be recorded in the system log,
you can build C-Kermit with forced syslogging at the desired level,
Levels 2 and 3 are the most likely candidates for this treatment.
Level 2 forces logging of all successful dialout calls (e.g. for
checking against or phone bills), and level 3 records all connections
(SET LINE or SET HOST / TELNET / RLOGIN, etc) so you can see who is
connecting out from your system, and to where.
Level 2 and 3 records are equivalent to those in the connection log;
see the [343]C-Kermit 7.0 Supplement) for a detailed description of
the connection log.
[ [344]Top ] [ [345]Contents ] [ [346]Next ] [ [347]Previous ]
C-Kermit 7.0 and later may be built with Kerberos(TM) and/or SRP(TM)
(Secure Remote Password) and/or SSL/TLS security for strong
authentication and encryption of Internet connections. These security
methods require external libraries that, in their binary forms, are
restricted from export by USA law. See the [348]Kermit Security
Reference) for details. C-Kermit binaries themselves are likewise
restricted; the C-Kermit binaries that are available for public
download on the Internet are not allowed to contain the security
Sample makefile entries are provided for Linux and many other
operating systems. A list of secure makefile entries is included in
the Makefile. Complete instructions on building C-Kermit 8.0 with MIT
Kerberos; Secure Remote Password; and/or OpenSSL can be found in the
[349]Kermit Security Reference.
C-Kermit 8.0 comes with a current list of Certificate Authority
certificates, including one for the Kermit Project that can be used
for authentication to Columbia's [350]Internet Kermit Service (IKSD).
You can use C-Kermit 7.0 or later to access Columbia's IKSD securely
by installing the Kermit Project certificate in
/usr/local/ssl/cert.pem (or the appropriate location based upon the
installation of OpenSSL on your system). You can find a copy of the
certificates file at:
[ [352]Top ] [ [353]Contents ] [ [354]Previous ]
This requires C-Kermit 8.0.206 or later and an SSH v2 server. If you
list C-Kermit as a Subsystem in the SSH v2 server configuration file
(as, for example, SFTP is listed), users can make SSH connections
direct to a Kermit server as explained here:
The name and location of the SSH server configuration file depends on
your platform, which SSH product(s) you have, etc. C-Kermit itself
must be referred to in this file as "kermit-sshsub". On the host,
install the C-Kermit 8.0.211 binary in the normal way. Then, in the
same directory as the C-Kermit binary, make a symbolic link:
ln -s kermit kermit-sshsub
(Note: the "make install" makefile target does this for you.) Then in
the sshd configuration file, add a line:
Subsystem kermit /some/path/kermit-sshsub
(where /some/path is the fully specified directory where the symlink
is.) This is similar to the line that sets up the SFTP susbsystem.
Subsystem sftp /usr/local/libexec/sftp-server
Subsystem kermit /usr/local/bin/kermit-sshsub
The mechanics might vary for other SSH servers; "man sshd" for
details. The method shown here is used because the OpenSSH server does
not permit the subsystem invocation to include command-line options.
C-Kermit would have no way of knowing that it should enter Server mode
if it were not called by a special name.
[ [356]Top ] [ [357]Contents ] [ [358]C-Kermit Home ] [ [359]C-Kermit
8.0 Overview ] [ [360]Kermit Home ]
C-Kermit 8.0 Unix Installation Instructions / The Kermit Project /
Columbia University / 10 April 2004