Programmable completion specification (compspec) for the bash shell to support the ipset program (netfilter.org).
Programmable completion allows the user, while working in an interactive shell, to retrieve and auto-complete commands, their options, filenames, etc. Pressing [TAB] will complete on the current word, if only one match is found. If multiple completions are possible, they will be listed by hitting [TAB] again.
This completion specification follows the logic of ipset and will show commands and options only when they are available for the current context (combination of commands and/or options). Providing some kind of interactive help.
Put it into ~/.bash_completion or /etc/bash_completion.d/.
Tip: To make tab completion more handsome put the following into either /etc/inputrc or ~/.inputrc:
set show-all-if-ambiguous on
This will allow single tab completion as opposed to requiring a double tab.
set page-completions off
This turns off the use of the internal pager when returning long completion lists.
Type -[TAB] to start option completion. Sets named - (hyphen) or starting with it, are supported, excluded are option names (i.e. -exist).
Type [TAB] to complete on anything available at the current context.
Depending on the environment variable _IPSET_COMPL_OPT_FORMAT, either the long, short or both forms of options are shown for completion. By default (empty _IPSET_COMPL_OPT_FORMAT) the long versions of options are displayed (_IPSET_COMPL_OPT_FORMAT=long also does the same). Setting it to ‘short’ will cause completion to show only the short form. Setting it to any other value, will result in both version being displayed and completed.
To complete named port ranges, enter the hypen after the first completed service (port) name, hit [TAB] again to start completion on the second named port (the brackets [] for service names containing a - (hyphen) are already surrounding the name in the completion list).
The environment variable HOSTFILE controls how hostname completion is performed. Taking the description from the bash man-page:
Contains the name of a file in the same format as /etc/hosts that should be read when the shell needs to complete a hostname. The list of possible hostname completions may be changed while the shell is running the next time hostname completion is attempted after the value is changed, bash adds the contents of the new file to the existing list. If HOSTFILE is set, but has no value, or does not name a readable file, bash attempts to read /etc/hosts to obtain the list of possible hostname completions. When HOSTFILE is unset, the hostname list is cleared.
As it is impossible to distinguish between IPv4 and IPv6 hostnames without resolving them, it is considered best practice to seperate IPv4 hosts from IPv6 hosts in different files.
If the bash-completion package is available hostname completion is extended the following way (description from bash-completion source):
Helper function for completing _known_hosts. This function performs host completion based on ssh config and known_hosts files, as well as hostnames reported by avahi-browse if COMP_KNOWN_HOSTS_WITH_AVAHI is set to a non-empty value. Also hosts from HOSTFILE (compgen -A hostname) are added, unless COMP_KNOWN_HOSTS_WITH_HOSTFILE is set to an empty value.
Also the environment variable _IPSET_SSH_CONFIGS controls which files are taken as ssh_config files, in order to retrieve the global and user known_host files, which will be used for hostname completion.
For all net type of sets and the hash:ip,mark set type, if hostname completion is attempted, if the environment variable _IPSET_COMP_NETWORKS is set to a non-empty value, networks are retrieved from /etc/networks.
Also a list of ip addresses can be supplied using the environment variable _IPSET_IPLIST_FILE. Which should point to a file containing an ip address per line. They can be ipv4 and/or ipv6. Detection which type should be included is done automatically based on the set header.
When deleting elements from any but list:set set types: the environment variable _IPSET_COMPL_DEL_MODE is queried to decide how to complete. If it is set to ‘members’ it will list the members of the set. If it is set to ‘spec’ it will follow the format of a port specification ([proto:]port). If it is set to any other value both methods are used to generate the list of possible completions (this is the default).
When testing elements from any but list:set set types: the environment variable _IPSET_COMPL_TEST_MODE is queried to decide how to complete. If it is set to ‘members’ it will list the members of the set. If it is set to ‘spec’ it will follow the format of a port specification ([proto:]port). If it is set to any other value both methods are used to generate the list of possible completions (this is the default).
When adding elements to a bitmap:ip,mac type of set, the environment variable _IPSET_MACLIST_FILE will be queried for a file containing a list of mac addresses. The file should contain one mac address per line. Empty lines and comments (also after the address) are supported. If the variable is unset mac addresses are fetched from arp cache, /etc/ethers and the output of ip link show.
When adding elements to one of the following set types: hash:ip,port hash:ip,port,ip hash:ip,port,net hash:net,port hash:net,port,net and completion is attempted on the port specification, the list of possible completions may become quite long. Especially if no characters are given to match on. This behaviour is because of the many different values such a port specification can possibly have.
At any time completion on variable names (starting with ‘$’ or ‘${’), or command substitution (starting with ‘$(’) is available. Using this with values validated by input validation, will stop further completion. In that case it is recommended to disable input validation (see below).
If the environment variable _IPSET_VALIDATE_INPUT is set to a non empty value validation of users input is disabled.
If the environment variable _DEBUG_NF_COMPLETION is defined (any value) debugging information is displayed.
Compatible with ipset versions 6+.
Tested with ipset v6.20.1.
bash v4+ is required.
Compatibility for future ipset versions cannot be promised, as new options may appear, which of course are currently unpredictable.
The bash-completion (v2.0+) package is highly recommended, though not mandatory.
http://bash-completion.alioth.debian.org/
Some things might not be that reliable or feature rich without it. Also the colon (if there) is removed from COMP_WORDBREAKS. This alteration is globally, which might affect other completions, if they do not take care of it themselves.
The iproute program (ip) is needed to display information about the local system.
https://github.com/AllKind/ipset-bash-completion
http://sourceforge.net/projects/ipset-bashcompl/
Please report bugs!