| <html lang="en"> |
| <head> |
| <title>Missing Pieces - The GNU C Library</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="The GNU C Library"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="Implementing-a-Shell.html#Implementing-a-Shell" title="Implementing a Shell"> |
| <link rel="prev" href="Continuing-Stopped-Jobs.html#Continuing-Stopped-Jobs" title="Continuing Stopped Jobs"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| This file documents the GNU C library. |
| |
| This is Edition 0.12, last updated 2007-10-27, |
| of `The GNU C Library Reference Manual', for version |
| 2.8 (Sourcery G++ Lite 2011.03-41). |
| |
| Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002, |
| 2003, 2007, 2008, 2010 Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.3 or |
| any later version published by the Free Software Foundation; with the |
| Invariant Sections being ``Free Software Needs Free Documentation'' |
| and ``GNU Lesser General Public License'', the Front-Cover texts being |
| ``A GNU Manual'', and with the Back-Cover Texts as in (a) below. A |
| copy of the license is included in the section entitled "GNU Free |
| Documentation License". |
| |
| (a) The FSF's Back-Cover Text is: ``You have the freedom to |
| copy and modify this GNU manual. Buying copies from the FSF |
| supports it in developing GNU and promoting software freedom.''--> |
| <meta http-equiv="Content-Style-Type" content="text/css"> |
| <style type="text/css"><!-- |
| pre.display { font-family:inherit } |
| pre.format { font-family:inherit } |
| pre.smalldisplay { font-family:inherit; font-size:smaller } |
| pre.smallformat { font-family:inherit; font-size:smaller } |
| pre.smallexample { font-size:smaller } |
| pre.smalllisp { font-size:smaller } |
| span.sc { font-variant:small-caps } |
| span.roman { font-family:serif; font-weight:normal; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="Missing-Pieces"></a> |
| <p> |
| Previous: <a rel="previous" accesskey="p" href="Continuing-Stopped-Jobs.html#Continuing-Stopped-Jobs">Continuing Stopped Jobs</a>, |
| Up: <a rel="up" accesskey="u" href="Implementing-a-Shell.html#Implementing-a-Shell">Implementing a Shell</a> |
| <hr> |
| </div> |
| |
| <h4 class="subsection">27.6.7 The Missing Pieces</h4> |
| |
| <p>The code extracts for the sample shell included in this chapter are only |
| a part of the entire shell program. In particular, nothing at all has |
| been said about how <code>job</code> and <code>program</code> data structures are |
| allocated and initialized. |
| |
| <p>Most real shells provide a complex user interface that has support for |
| a command language; variables; abbreviations, substitutions, and pattern |
| matching on file names; and the like. All of this is far too complicated |
| to explain here! Instead, we have concentrated on showing how to |
| implement the core process creation and job control functions that can |
| be called from such a shell. |
| |
| <p>Here is a table summarizing the major entry points we have presented: |
| |
| <dl> |
| <dt><code>void init_shell (void)</code><dd>Initialize the shell's internal state. See <a href="Initializing-the-Shell.html#Initializing-the-Shell">Initializing the Shell</a>. |
| |
| <br><dt><code>void launch_job (job *</code><var>j</var><code>, int </code><var>foreground</var><code>)</code><dd>Launch the job <var>j</var> as either a foreground or background job. |
| See <a href="Launching-Jobs.html#Launching-Jobs">Launching Jobs</a>. |
| |
| <br><dt><code>void do_job_notification (void)</code><dd>Check for and report any jobs that have terminated or stopped. Can be |
| called synchronously or within a handler for <code>SIGCHLD</code> signals. |
| See <a href="Stopped-and-Terminated-Jobs.html#Stopped-and-Terminated-Jobs">Stopped and Terminated Jobs</a>. |
| |
| <br><dt><code>void continue_job (job *</code><var>j</var><code>, int </code><var>foreground</var><code>)</code><dd>Continue the job <var>j</var>. See <a href="Continuing-Stopped-Jobs.html#Continuing-Stopped-Jobs">Continuing Stopped Jobs</a>. |
| </dl> |
| |
| <p>Of course, a real shell would also want to provide other functions for |
| managing jobs. For example, it would be useful to have commands to list |
| all active jobs or to send a signal (such as <code>SIGKILL</code>) to a job. |
| |
| </body></html> |
| |
