ENV_PARALLEL(1)

NAME
env_parallel - export environment to GNU parallel

SYNOPSIS
env_parallel [options for GNU Parallel]

DESCRIPTION
env_parallel is a shell function that exports the current environment to GNU parallel.

If the shell function is not loaded, a dummy script will be run instead that explains how to install the function.

env_parallel is beta quality and not production ready, but please use it for everyday use and report bugs.

env_parallel is 0.1 sec slower at startup than pure GNU parallel, and takes up to 15 ms to start a job.

Due to the problem with environment space (see below) the recommended usage is:

  # Run once to record the "empty" environment
  env_parallel --record-env

  # Define whatever you want to use
  alias myalias=echo
  myvar=it
  myfunc() { myalias $1 $myvar works.; }

  # Use --env _ to only transfer the names not in the "empty" environment
  env_parallel --env _ -S localhost myfunc ::: Yay,

In csh:

  # Run once to record the "empty" environment
  env_parallel --record-env

  # Define whatever you want to use
  alias myalias 'echo \!* $myvar works.'
  set myvar=it

  # Use --env _ to only transfer the names not in the "empty" environment
  env_parallel --env _ -S localhost myalias ::: Yay,

  Environment space
By default env_parallel will export all environment variables, arrays, aliases, functions and shell options (see details for the individual shells below).

But this only works if the size of the current environment is smaller than the maximal length of a command and smaller than half of the max if running remotely. E.g. The max size of Bash's command is 128 KB, so env_parallel will fail if set | wc -c is bigger than 128 KB. Technically the limit is in execve(1) which IPC::open3 uses.

Bash completion functions are well-known for taking up well over 128 KB of environment space and the primary reason for causing env_parallel to fail.

Instead you can use --env to specify which variables, arrays, aliases and functions to export as this will only export those with the given name.

OPTIONS
Same as GNU parallel.

SUPPORTED SHELLS

  Bash
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.

Installation

Put this in $HOME/.bashrc:

  . `which env_parallel.bash`

E.g. by doing:

  echo '. `which env_parallel.bash`' >> $HOME/.bashrc

aliases
      alias myecho='echo aliases'
      env_parallel myecho ::: work
      env_parallel -S server myecho ::: work
      env_parallel --env myecho myecho ::: work
      env_parallel --env myecho -S server myecho ::: work

functions
      myfunc() { echo functions $*; }
      env_parallel myfunc ::: work
      env_parallel -S server myfunc ::: work
      env_parallel --env myfunc myfunc ::: work
      env_parallel --env myfunc -S server myfunc ::: work

variables
      myvar=variables
      env_parallel echo '$myvar' ::: work
      env_parallel -S server echo '$myvar' ::: work
      env_parallel --env myvar echo '$myvar' ::: work
      env_parallel --env myvar -S server echo '$myvar' ::: work

arrays
      myarray=(arrays work, too)
      env_parallel -k echo '${myarray[{}]}' ::: 0 1 2
      env_parallel -k -S server echo '${myarray[{}]}' ::: 0 1 2
      env_parallel -k --env myarray echo '${myarray[{}]}' ::: 0 1 2
      env_parallel -k --env myarray -S server echo '${myarray[{}]}' ::: 0 1 2

  csh
--env is supported to export only the variable, alias, or array with the given name. Multiple --envs can be given.

env_parallel for csh breaks $PARALLEL, so do not use $PARALLEL.

Installation

Put this in $HOME/.cshrc:

  source `which env_parallel.csh`

E.g. by doing:

  echo 'source `which env_parallel.csh`' >> $HOME/.cshrc

aliases
      alias myecho 'echo aliases'
      env_parallel myecho ::: work
      env_parallel -S server myecho ::: work
      env_parallel --env myecho myecho ::: work
      env_parallel --env myecho -S server myecho ::: work

functions
    Not supported by csh.

variables
      set myvar=variables
      env_parallel echo '$myvar' ::: work
      env_parallel -S server echo '$myvar' ::: work
      env_parallel --env myvar echo '$myvar' ::: work
      env_parallel --env myvar -S server echo '$myvar' ::: work

arrays with no special chars
      set myarray=(arrays work, too)
      env_parallel -k echo \$'{myarray[{}]}' ::: 1 2 3
      env_parallel -k -S server echo \$'{myarray[{}]}' ::: 1 2 3
      env_parallel -k --env myarray echo \$'{myarray[{}]}' ::: 1 2 3
      env_parallel -k --env myarray -S server echo \$'{myarray[{}]}' ::: 1 2 3

  fish
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.

Installation

Put this in $HOME/.config/fish/config.fish:

  source (which env_parallel.fish)

E.g. by doing:

  echo 'source (which env_parallel.fish)' >> $HOME/.config/fish/config.fish

aliases
      alias myecho 'echo aliases'
      env_parallel myecho ::: work
      env_parallel -S server myecho ::: work
      env_parallel --env myecho myecho ::: work
      env_parallel --env myecho -S server myecho ::: work

functions
      function myfunc
        echo functions $argv
      end
      env_parallel myfunc ::: work
      env_parallel -S server myfunc ::: work
      env_parallel --env myfunc myfunc ::: work
      env_parallel --env myfunc -S server myfunc ::: work

variables
      set myvar variables
      env_parallel echo '$myvar' ::: work
      env_parallel -S server echo '$myvar' ::: work
      env_parallel --env myvar echo '$myvar' ::: work
      env_parallel --env myvar -S server echo '$myvar' ::: work

arrays
      set myarray arrays work, too
      env_parallel -k echo '$myarray[{}]' ::: 1 2 3
      env_parallel -k -S server echo '$myarray[{}]' ::: 1 2 3
      env_parallel -k --env myarray echo '$myarray[{}]' ::: 1 2 3
      env_parallel -k --env myarray -S server echo '$myarray[{}]' ::: 1 2 3

  ksh
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.

Installation

Put this in $HOME/.kshrc:

  source `which env_parallel.ksh`

E.g. by doing:

  echo 'source `which env_parallel.ksh`' >> $HOME/.kshrc

aliases
      alias myecho='echo aliases'
      env_parallel myecho ::: work
      env_parallel -S server myecho ::: work
      env_parallel --env myecho myecho ::: work
      env_parallel --env myecho -S server myecho ::: work

functions
      myfunc() { echo functions $*; }
      env_parallel myfunc ::: work
      env_parallel -S server myfunc ::: work
      env_parallel --env myfunc myfunc ::: work
      env_parallel --env myfunc -S server myfunc ::: work

variables
      myvar=variables
      env_parallel echo '$myvar' ::: work
      env_parallel -S server echo '$myvar' ::: work
      env_parallel --env myvar echo '$myvar' ::: work
      env_parallel --env myvar -S server echo '$myvar' ::: work

arrays
      myarray=(arrays work, too)
      env_parallel -k echo '${myarray[{}]}' ::: 0 1 2
      env_parallel -k -S server echo '${myarray[{}]}' ::: 0 1 2
      env_parallel -k --env myarray echo '${myarray[{}]}' ::: 0 1 2
      env_parallel -k --env myarray -S server echo '${myarray[{}]}' ::: 0 1 2

  pdksh
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.

Installation

Put this in $HOME/.profile:

  source `which env_parallel.pdksh`

E.g. by doing:

  echo 'source `which env_parallel.pdksh`' >> $HOME/.profile

aliases
      alias myecho="echo aliases";
      env_parallel myecho ::: work;
      env_parallel -S server myecho ::: work;
      env_parallel --env myecho myecho ::: work;
      env_parallel --env myecho -S server myecho ::: work

functions
      myfunc() { echo functions $*; };
      env_parallel myfunc ::: work;
      env_parallel -S server myfunc ::: work;
      env_parallel --env myfunc myfunc ::: work;
      env_parallel --env myfunc -S server myfunc ::: work

variables
      myvar=variables;
      env_parallel echo "\$myvar" ::: work;
      env_parallel -S server echo "\$myvar" ::: work;
      env_parallel --env myvar echo "\$myvar" ::: work;
      env_parallel --env myvar -S server echo "\$myvar" ::: work

arrays
      myarray=(arrays work, too);
      env_parallel -k echo "\${myarray[{}]}" ::: 0 1 2;
      env_parallel -k -S server echo "\${myarray[{}]}" ::: 0 1 2;
      env_parallel -k --env myarray echo "\${myarray[{}]}" ::: 0 1 2;
      env_parallel -k --env myarray -S server echo "\${myarray[{}]}" ::: 0 1 2

  tcsh
--env is supported to export only the variable, alias, or array with the given name. Multiple --envs can be given.

env_parallel for tcsh breaks $PARALLEL, so do not use $PARALLEL.

Installation

Put this in $HOME/.tcshrc:

  source `which env_parallel.tcsh`

E.g. by doing:

  echo 'source `which env_parallel.tcsh`' >> $HOME/.tcshrc

aliases
      alias myecho 'echo aliases'
      env_parallel myecho ::: work
      env_parallel -S server myecho ::: work
      env_parallel --env myecho myecho ::: work
      env_parallel --env myecho -S server myecho ::: work

functions
    Not supported by tcsh.

variables
      set myvar=variables
      env_parallel echo '$myvar' ::: work
      env_parallel -S server echo '$myvar' ::: work
      env_parallel --env myvar echo '$myvar' ::: work
      env_parallel --env myvar -S server echo '$myvar' ::: work

arrays with no special chars
      set myarray=(arrays work, too)
      env_parallel -k echo \$'{myarray[{}]}' ::: 1 2 3
      env_parallel -k -S server echo \$'{myarray[{}]}' ::: 1 2 3
      env_parallel -k --env myarray echo \$'{myarray[{}]}' ::: 1 2 3
      env_parallel -k --env myarray -S server echo \$'{myarray[{}]}' ::: 1 2 3

  Zsh
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.

Installation

Put this in $HOME/.zshrc:

  . `which env_parallel.zsh`

E.g. by doing:

  echo '. `which env_parallel.zsh`' >> $HOME/.zshenv

aliases
      alias myecho='echo aliases'
      env_parallel myecho ::: work
      env_parallel -S server myecho ::: work
      env_parallel --env myecho myecho ::: work
      env_parallel --env myecho -S server myecho ::: work

functions
      myfunc() { echo functions $*; }
      env_parallel myfunc ::: work
      env_parallel -S server myfunc ::: work
      env_parallel --env myfunc myfunc ::: work
      env_parallel --env myfunc -S server myfunc ::: work

variables
      myvar=variables
      env_parallel echo '$myvar' ::: work
      env_parallel -S server echo '$myvar' ::: work
      env_parallel --env myvar echo '$myvar' ::: work
      env_parallel --env myvar -S server echo '$myvar' ::: work

arrays
      myarray=(arrays work, too)
      env_parallel -k echo '${myarray[{}]}' ::: 1 2 3
      env_parallel -k -S server echo '${myarray[{}]}' ::: 1 2 3
      env_parallel -k --env myarray echo '${myarray[{}]}' ::: 1 2 3
      env_parallel -k --env myarray -S server echo '${myarray[{}]}' ::: 1 2 3

EXIT STATUS
Same as GNU parallel.

AUTHOR
When using GNU parallel for a publication please cite:

O. Tange (2011): GNU Parallel - The Command-Line Power Tool, ;login: The USENIX Magazine, February 2011:42-47.

This helps funding further development; and it won't cost you a cent. If you pay 10000 EUR you should feel free to use GNU Parallel without citing.

Copyright (C) 2007-10-18 Ole Tange, http://ole.tange.dk

Copyright (C) 2008,2009,2010 Ole Tange, http://ole.tange.dk

Copyright (C) 2010,2011,2012,2013,2014,2015,2016,2017 Ole Tange, http://ole.tange.dk and Free Software Foundation, Inc.

Parts of the manual concerning xargs compatibility is inspired by the manual of xargs from GNU findutils 4.4.2.

LICENSE
Copyright (C) 2016 Ole Tange and Free Software Foundation, Inc.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or at your option any later version.

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 the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

  Documentation license I
Permission is granted to copy, distribute and/or modify this documentation under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the file fdl.txt.

  Documentation license II
You are free:

to Share
    to copy, distribute and transmit the work

to Remix
    to adapt the work

Under the following conditions:

Attribution
    You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).

Share Alike
    If you alter, transform, or build upon this work, you may distribute the resulting work only under the same, similar or a compatible license.

With the understanding that:

Waiver
    Any of the above conditions can be waived if you get permission from the copyright holder.

Public Domain
    Where the work or any of its elements is in the public domain under applicable law, that status is in no way affected by the license.

Other Rights
    In no way are any of the following rights affected by the license:

    •   Your fair dealing or fair use rights, or other applicable copyright exceptions and limitations;

    •   The author's moral rights;

    •   Rights other persons may have either in the work itself or in how the work is used, such as publicity or privacy rights.

Notice
    For any reuse or distribution, you must make clear to others the license terms of this work.

A copy of the full license is included in the file as cc-by-sa.txt.

DEPENDENCIES
env_parallel uses GNU parallel.

SEE ALSO
parallel(1),

bash(1), csh(1), fish(1), ksh(1), pdksh(1) tcsh(1), zsh(1).