zoid - a modular perl shell


zoid [options] [-] [files]


Zoidberg provides a modular Perl shell written, configured, and operated entirely in Perl. It aspires to be a fully operational login shell with all the features one normally expects. But it also gives direct access to Perl objects and data structures from the command line, and allows you to run Perl code within the scope of your commandline. Although Zoidberg does not do the language interpreting itself -- it uses perl to do this -- it supplies powerful language extensions aimed at creating an easy to use interface.

By default zoid runs an interactive commandline when both STDIN and STDOUT are terminal devices, or reads from STDIN till End Of Line and execute each line like it was entered interactively. When an action is specified by one of the commandline options this will suppress the default behavior and exit after executing that action. If any file names are given, these will be interpreted as source scripts and suppress default behavior. Be aware that these source scripts are expected to be Perl scripts and are NOT interpreted or executed the same way as normal input.

This document only describes the commandline script zoid, see zoiduser(1) and zoidfaq(1) for help on using the zoidberg shell.


-e command, --exec=command

Execute a string as interpreted by zoidberg. If non-interactive exits with exit status of command string. Multiple commands may be given to build up a multi-line script. Make sure to use semicolons where you would in a normal multi-line script.

-C, --config

Print a list of configuration variable of this installation and exit. Most importantly this tells you where zoid will search for it's configuration and data files.

-c command, --command=command

Does the same as --exec but this is bound to change.

-D, -DClass --debug

Set either the global debug bit or set the debug bit for the given class. Using the global variant makes zoid output a lot of debug information.

-h, --help
-u, --usage

Print a help message and exits.

-Idir[,dir, ...]

The specified directories are added to the module search path @INC.

-i, --interactive

Start an interactive shell. This is the default if no other options are supplied.

-l, --login

Force login behavior, this will reset your current working directory. This variable is also available to plugins and scripts, which might act on it.

-Mmodule=args[,arg, ...]

Import module into the eval namespace. With -m explicit import empty list, with -M default arguments or specified arguments. Details like the equivalent perl option, see perlrun(1).

-o setting
-o setting=value
+o setting

Set (-o) or unset (+o) one or more settings.

-s, --stdin

Read input from stdin. This is the default if no other options are supplied and neither stdin or stdout are terminal devices.

-V, --version

Display version information.

-v, --verbose

Sets the shell in verbose mode. This will cause each command to be echoed to STDERR.


The variables $PWD, $HOME and $USER are set to default values if not yet set by the parent process.

The variable $ZOID will point to the location of the zoid executable, it is similar to $SHELL for POSIX compliant shells. zoid uses a different variable because some programs seem to expect $SHELL to point to a POSIX compliant shell.

To switch off ansi colours on the terminal set $CLICOLOR to 0 (null).


Zoidberg uses rc files, data files and plugin files, use the --config switch to check the search paths used.

Which rcfiles are loaded is controlled be the 'rcfiles' and 'norc' settings, try zoid -o norc to skip all rcfiles or zoid -o rcfiles=file1:file2:file3 to use files other then the default.

The runtime search path for plugins etc. can be controlled with the 'data_dirs' setting, try zoid -o data_dirs=dir1:dir2:dir3.


Error messages may be issued either by perl or by one any of the modules in use. The zoid utility itself will only complain when the commandline options are wrong. If the error was thrown by one of zoid's core modules, the error message will either start with the module name or the name of the command that went wrong.


Source files and command input are NOT interpreted the same way.

Use -e _or_ -c, do not mix them.


To submit bug reports visit or mail the author.


perl(1), zoiduser(1), zoidbuiltins(1), zoiddevel(1), zoidfaq(1), Zoidberg(3),


Jaap Karssenberg || Pardus [Larus] <>

R.L. Zwart, <>


Copyright (c) 2011 Jaap G Karssenberg and Joel Berger and RL Zwart. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See either the GNU General Public License or the Artistic License for more details.

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