shcompgen - Generate shell completion scripts
This document describes version 0.325 of shcompgen (from Perl distribution App-shcompgen), released on 2022-10-07.
Initialize (this will create completion scripts directory, create shell script to initialize completion system):
% shcompgen init
Generate shell completion scripts for all detectable programs in PATH:
% shcompgen generate
Note that this distribution automatically runs 'init' and 'generate' the first time it is installed, or when you upgrade from an older version. So normally you don't have to do this manually.
Generate some programs only, replace if previously already exists, be verbose:
% shcompgen generate --verbose --replace prog1 prog2 ./bin/prog3
List all shell completion scripts generated by us:
% shcompgen list
% shcompgen list --detail
Remove some shell completion scripts:
% shcompgen remove prog1 prog2
Remove all generated shell completion scripts:
% shcompgen remove
Some shells, like bash/fish/zsh/tcsh, supports tab completion for programs. They are usually activated by issuing one or more complete (zsh uses compctl) internal shell commands. The completion scripts which contain these commands are usually put in (e.g., for fish) /etc/fish/completion/PROGNAME.fish (if one wants to install globally) or ~/.config/fish/completions/PROGNAME.fish (if one wants to install per-user).
This utility, shcompgen, can detect how to generate shell completion scripts for some programs and then install the completion scripts into the abovementioned location (the default is to per-user directory, but if running as root or with --global switch will install to the global directory).
It can also list all completion scripts generated by it, and be instructed to uninstall them again.
It supports several shells, currently: bash, fish, zsh, and tcsh. Shell-specific information can be found below.
This script can work with the bash-completion package (and uses the same global completion directory: /etc/bash_completion.d). At the time of this writing, bash-completion (at version 2.1) does not yet look at per-user completion scripts directory. This script picks ~/.config/bash/completions/PROGNAME as location for per-user completion scripts. If later on bash-completion package decides on a different per-user location, this script will probably be adjusted too.
Known issues include proper escaping of completion answer (e.g. when an answer contains a whitespace). To demonstrate this problem, try peri-eg-complete-fruits-any and type:
% peri-eg-complete-fruits-any --fruit <tab>
The answer butternut squash is returned as butternut\\\ squash.
So far I couldn't get fallback (a.k.a catch-all) completion mechanism to work in tcsh. For example if I do:
complete '*' 'p/*/`helper`/'
then it will eclipse the other existing completion definitions.
So in tcsh, activating (or deactivating) completion is currently less convenient compared to the other shells. Instead of the complete definitions being put on a per-command basis in ~/.config/tcsh/completions/ directory, the init script ~/.config/shcompgen.tcsh will directly contain all the complete definitions. This script must be sourced to update the definitions. So after you
% shcompgen generate foo
you will need to re-source the init script (or logout from + login back to the shell). And after you remove a completion script, you will need to uncomplete + re-source the init script (or logout from + login back to the shell).
The answer butternut squash is only returned as butternut\\ .
Another known issue is still having to compinit after shcompgen generate or shcompgen remove.
And yet another known issue is having to compinit in the init script (~/.config/shcompgen.zsh) which is slowing down the shell startup.
Below are the types/kinds of programs that can be detected. Expect the list to expand as more methods are added.
Scripts which are tagged with hints of what completion program to use
You can put this line in a script, e.g. in a script called foo:
# FRAGMENT id=shcompgen-hint command=bar
The above line tells shcompgen that the script should be completed using an external program called bar. This will construct this completion script, e.g. for bash:
complete -C bar foo
Completion programs which are tagged with hints of what programs they complete
You can create a completion script in Perl (or other language, actually), e.g. _foo and tag it with hints of what programs they complete, e.g.
# FRAGMENT id=shcompgen-hint completer=1 for=foo,foo-this-host
This will add completion script for foo:
complete -C _foo foo
as well as for foo-this-host:
complete -C _foo foo-this-host
Getopt::Long::Complete-based CLI scripts
If a script foo is detected as a Perl script using Getopt::Long::Complete, we know that it can complete itself. Thus, shcompgen will generate this completion script (e.g. for bash):
complete -C foo foo
Getopt::Long::Subcommand-based CLI scripts
If a script foo is detected as a Perl script using Getopt::Long::Subcommand, we know that it can complete itself. Thus, shcompgen will generate this completion script (e.g. for bash):
Getopt::Long-based CLI scripts
If a script foo is detected as a Perl script using Getopt::Long, shcompgen will try to extract the Getopt::Long spec specified by GetOptions, which can then tell it what options a script accepts. The completion script cannot complete option values or arguments though, as there is not enough information to do that. If you write the script, you might want to switch to Getopt::Long::Complete or Getopt::Long::Subcommand for better tab completion support.
Getopt::Long::EvenLess-based CLI scripts
Basically the same as Getopt::Long-based scripts.
Getopt::Long::Descriptive-based CLI scripts
Getopt::Std-based CLI scripts
Perinci::CmdLine-based CLI scripts
If a script like foo is detected as a Perl script using Perinci::CmdLine (or its variant like Perinci::CmdLine::Lite or Perinci::CmdLine::Any) we know that it can complete itself. Thus, shcompgen will add this completion script e.g. for bash:
Other methods will be added in the future, e.g. by parsing manpage or POD, and so on.
(Utility) Guess running shell.
Generate shell completion scripts for detectable programs.
(Utility) detect a program.
This subcommand creates the completion directories and initialization shell script, as well as run generate.
List all shell completion scripts generated by this script.
Remove shell completion scripts generated by this script.
* marks required options.
Set path to configuration file.
Can actually be specified multiple times to instruct application to read from multiple configuration files (and merge them).
Set configuration profile to use.
A single configuration file can contain profiles, i.e. alternative sets of values that can be selected. For example:
When you specify --config-profile=dev, username will be set to foo and password to beaver. When you specify --config-profile=production, username will be set to bar and password to honey.
Shortcut for --log-level=debug.
Shortcut for --shell=fish.
Choose output format, e.g. json, text.
Output can be displayed in multiple formats, and a suitable default format is chosen depending on the application and/or whether output destination is interactive terminal (i.e. whether output is piped). This option specifically chooses an output format.
Display help message and exit.
Set output format to json.
Set log level.
By default, these log levels are available (in order of increasing level of importance, from least important to most): trace, debug, info, warn/warning, error, fatal. By default, the level is usually set to warn, which means that log statements with level info and less important levels will not be shown. To increase verbosity, choose info, debug, or trace.
For more details on log level and logging, as well as how new logging levels can be defined or existing ones modified, see Log::ger.
When outputing as JSON, strip result envelope.
By default, when outputing as JSON, the full enveloped result is returned, e.g.:
The reason is so you can get the status (1st element), status message (2nd element) as well as result metadata/extra result (4th element) instead of just the result (3rd element). However, sometimes you want just the result, e.g. when you want to pipe the result for more post-processing. In this case you can use --naked-res so you just get:
Do not use any configuration file.
If you specify --no-config, the application will not read any configuration file.
Do not read environment for default options.
If you specify --no-env, the application wil not read any environment variable.
Filter output through a pager.
This option will pipe the output to a specified pager program. If pager program is not specified, a suitable default e.g. less is chosen.
Shortcut for --log-level=error.
Override guessing and select shell manually.
List available subcommands.
Shortcut for --shell=tcsh.
Shortcut for --log-level=trace.
Shortcut for --log-level=info.
Display program's version and exit.
View output using a viewer.
This option will first save the output to a temporary file, then open a viewer program to view the temporary file. If a viewer program is not chosen, a suitable default, e.g. the browser, is chosen.
Shortcut for --shell=zsh.
Can also be specified as the 1st command-line argument.
Create per-option completion script if possible.
If set to true, then attempt to create completion script that register each option. This creates nicer completion in some shells, e.g. fish and zsh. For example, option description can be shown.
This is possible for only some types of scripts, e.g. Perinci::CmdLine- (that does not have subcommands) or Getopt::Long::Descriptive-based ones.
Program(s) to generate completion for (JSON-encoded).
Can also be specified as the 1st command-line argument and onwards.
Program(s) to generate completion for.
Can contain path (e.g. ../foo) or a plain word (foo) in which case will be searched from PATH.
Can be specified multiple times.
Remove completion for script that (now) is not detected to have completion.
The default behavior is to simply ignore existing completion script if the program is not detected to have completion. When the remove setting is enabled, however, such existing completion script will be removed.
Replace existing script.
The default behavior is to skip if an existing completion script exists.
Output completion script to STDOUT.
Program(s) to remove completion script of (JSON-encoded).
Program(s) to remove completion script of.
This script has shell tab completion capability with support for several shells.
To activate bash completion for this script, put:
complete -C shcompgen shcompgen
in your bash startup (e.g. ~/.bashrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.
It is recommended, however, that you install modules using cpanm-shcompgen which can activate shell completion for scripts immediately.
To activate tcsh completion for this script, put:
complete shcompgen 'p/*/`shcompgen`/'
in your tcsh startup (e.g. ~/.tcshrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.
It is also recommended to install shcompgen (see above).
For fish and zsh, install shcompgen as described above.
This script can read configuration files. Configuration files are in the format of IOD, which is basically INI with some extra features.
By default, these names are searched for configuration filenames (can be changed using --config-path): /home/u1/.config/shcompgen.conf, /home/u1/shcompgen.conf, or /etc/shcompgen.conf.
All found files will be read and merged.
To disable searching for configuration files, pass --no-config.
To put configuration for a certain subcommand only, use a section name like [subcommand=NAME] or [SOMESECTION subcommand=NAME].
You can put multiple profiles in a single file by using section names like [profile=SOMENAME] or [SOMESECTION profile=SOMENAME] or [subcommand=SUBCOMMAND_NAME profile=SOMENAME] or [SOMESECTION subcommand=SUBCOMMAND_NAME profile=SOMENAME]. Those sections will only be read if you specify the matching --config-profile SOMENAME.
[SOMESECTION subcommand=SUBCOMMAND_NAME profile=SOMENAME]
You can also put configuration for multiple programs inside a single file, and use filter program=NAME in section names, e.g. [program=NAME ...] or [SOMESECTION program=NAME]. The section will then only be used when the reading program matches.
You can also filter a section by environment variable using the filter env=CONDITION in section names. For example if you only want a section to be read if a certain environment variable is true: [env=SOMEVAR ...] or [SOMESECTION env=SOMEVAR ...]. If you only want a section to be read when the value of an environment variable equals some string: [env=HOSTNAME=blink ...] or [SOMESECTION env=HOSTNAME=blink ...]. If you only want a section to be read when the value of an environment variable does not equal some string: [env=HOSTNAME!=blink ...] or [SOMESECTION env=HOSTNAME!=blink ...]. If you only want a section to be read when the value of an environment variable includes some string: [env=HOSTNAME*=server ...] or [SOMESECTION env=HOSTNAME*=server ...]. If you only want a section to be read when the value of an environment variable does not include some string: [env=HOSTNAME!*=server ...] or [SOMESECTION env=HOSTNAME!*=server ...]. Note that currently due to simplistic parsing, there must not be any whitespace in the value being compared because it marks the beginning of a new section filter or section name.
[SOMESECTION env=SOMEVAR ...]
[SOMESECTION env=HOSTNAME=blink ...]
[SOMESECTION env=HOSTNAME!=blink ...]
[SOMESECTION env=HOSTNAME*=server ...]
[SOMESECTION env=HOSTNAME!*=server ...]
To load and configure plugins, you can use either the -plugins parameter (e.g. -plugins=DumpArgs or -plugins=DumpArgs@before_validate_args), or use the [plugin=NAME ...] sections, for example:
which is equivalent to setting -plugins=-DumpArgs@before_validate_args@99,-Foo@after_validate_args,arg1,val1,arg2,val2.
List of available configuration parameters:
format (see --format)
log_level (see --log-level)
naked_res (see --naked-res)
shell (see --shell)
prog (see --prog)
per_option (see --per-option)
prog (see --prog)
remove (see --remove)
replace (see --replace)
stdout (see --stdout)
per_option (see --per-option)
detail (see --detail)
per_option (see --per-option)
per_option (see --per-option)
prog (see --prog)
String. Specify additional command-line options.
Please visit the project's homepage at https://metacpan.org/release/App-shcompgen.
Source repository is at https://github.com/perlancar/perl-App-shcompgen.
To contribute, you can send patches by email/via RT, or send pull requests on GitHub.
Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:
% prove -l
If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.
This software is copyright (c) 2022, 2020, 2018, 2017, 2016, 2015, 2014 by perlancar <email@example.com>.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=App-shcompgen
When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.
To install App::shcompgen, copy and paste the appropriate command in to your terminal.
perl -MCPAN -e shell
For more information on module installation, please visit the detailed CPAN module installation guide.