env_parallel - Man Page
export environment to GNU parallel
Synopsis
env_parallel [--record-env|--session|--end-session]
[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 100 ms slower at startup than pure GNU parallel, and takes up to 30% longer to start a job (typically 15 ms).
Due to the problem with environment space (see below) you are recommended only to transfer the environment that you need.
To help you do that, you can mark names that should not be transferred. This can be done with either --session or --record-env.
# Record the "clean" environment (this only needs to be run once) env_parallel --record-env # Optionally edit ~/.parallel/ignored_vars (only needed once) # Define whatever you want to use myfunc() { myalias and functions $myvar work. $1.; } alias myalias='echo Aliases' myvar='and variables' # Use --env _ to only transfer the names not in the "empty" environment env_parallel --env _ -S localhost myfunc ::: Hooray
Or:
# Do --record-env into $PARALLEL_IGNORED_NAMES env_parallel --session # Define whatever you want to use myfunc() { myalias and functions $myvar work. $1.; } alias myalias='echo Aliases' myvar='and variables' # env_parallel will not export names in $PARALLEL_IGNORED_NAMES env_parallel -S localhost myfunc ::: Hooray # Optionally env_parallel --end-session
In csh --session is not supported:
# Record the "clean" environment - this only needs to be run once env_parallel --record-env # Optionally edit ~/.parallel/ignored_vars - only needed once # Define whatever you want to use alias myalias 'echo Aliases $myvar \!*.' set myvar='and variables' # Use --env _ to only transfer the names not in the "empty" environment env_parallel --env _ -S localhost myalias ::: work
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. Or follow the recommended usage in shown in DESCRIPTION.
Options
Same as GNU parallel in addition to these:
- --end-session
Undo last --session
- --record-env
Record all names currently defined to be ignored every time running env_parallel in the future.
- --session
Ignore all names currently defined. Aliases, variables, arrays, and functions currently defined will not be transferred.
But names defined after running parallel --session will be transferred.
This is only valid in the running shell, and can be undone with parallel --end-session.
You can run multiple --session inside each other:
env_parallel --session var=not # var is transferred env_parallel -Slocalhost 'echo var is $var' ::: ignored env_parallel --session # var is not transferred env_parallel -Slocalhost 'echo var is $var' ::: ignored env_parallel --end-session # var is transferred again env_parallel -Slocalhost 'echo var is $var' ::: ignored
Supported Shells
Ash
Installation
Put this in $HOME
/.profile:
. env_parallel.ash
E.g. by doing:
echo '. env_parallel.ash' >> $HOME/.profile
Supported use
--env is supported to export only the variable, or alias with the given name. Multiple --envs can be given.
--session is supported.
- aliases
alias myecho='echo aliases' env_parallel myecho ::: work env_parallel -S server myecho ::: work env_parallel --env myecho myecho ::: work env_parallel --env myecho -S server myecho ::: work alias multiline='echo multiline echo aliases' env_parallel multiline ::: work env_parallel -S server multiline ::: work env_parallel --env multiline multiline ::: work env_parallel --env multiline -S server multiline ::: work
- functions
ash cannot list defined functions - thus is not supported.
- variables
myvar=variables env_parallel echo '$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
Arrays are not supported by Ash.
Bash
Installation
Put this in $HOME
/.bashrc:
. env_parallel.bash
E.g. by doing:
echo '. env_parallel.bash' >> $HOME/.bashrc
Supported use
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.
--session is supported.
- 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 alias multiline='echo multiline echo aliases' env_parallel 'multiline {}; echo but only when followed by a newline' ::: work env_parallel -S server 'multiline {}; echo but only when followed by a newline' ::: work env_parallel --env multiline 'multiline {}; echo but only when followed by a newline' ::: work env_parallel --env multiline -S server 'multiline {}; echo but only when followed by a newline' ::: 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
BUGS
Due to a bug in Bash, aliases containing newlines must be followed by a newline in the command. Some systems are not affected by this bug, but will print a warning anyway.
csh (beta testing)
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`' >> $HOME/.cshrc
Supported use
--env is supported to export only the variable, alias, or array with the given name. Multiple --envs can be given.
- aliases
alias myecho 'echo aliases' env_parallel myecho ::: work env_parallel -S server myecho ::: work env_parallel --env myecho myecho ::: work env_parallel --env myecho -S server myecho ::: work
- functions
Not supported by csh.
- variables
set myvar=variables env_parallel echo '$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
Dash
Installation
Put this in $HOME
/.profile:
. env_parallel.dash
E.g. by doing:
echo '. env_parallel.dash' >> $HOME/.profile
Supported use
--env is supported to export only the variable, or alias with the given name. Multiple --envs can be given.
--session is supported.
- aliases
alias myecho='echo aliases' env_parallel myecho ::: work env_parallel -S server myecho ::: work env_parallel --env myecho myecho ::: work env_parallel --env myecho -S server myecho ::: work alias multiline='echo multiline echo aliases' env_parallel multiline ::: work env_parallel -S server multiline ::: work env_parallel --env multiline multiline ::: work env_parallel --env multiline -S server multiline ::: work
- functions
dash cannot list defined functions - thus is not supported.
- variables
myvar=variables env_parallel echo '$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
dash does not support arrays.
fish
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
Supported use
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.
--session is supported.
- 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 '$myvar' ::: work
- arrays
Arrays normally work, but fail intermitently.
set myarray arrays work, too env_parallel -k echo '$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
Installation
Put this in $HOME
/.kshrc:
source env_parallel.ksh
E.g. by doing:
echo 'source env_parallel.ksh' >> $HOME/.kshrc
Supported use
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.
--session is supported.
- 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 alias multiline='echo multiline echo aliases' env_parallel multiline ::: work env_parallel -S server multiline ::: work env_parallel --env multiline multiline ::: work env_parallel --env multiline -S server multiline ::: 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
mksh
Installation
Put this in $HOME
/.mkshrc:
source env_parallel.mksh
E.g. by doing:
echo 'source env_parallel.mksh' >> $HOME/.mkshrc
Supported use
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.
--session is supported.
- 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 alias multiline='echo multiline echo aliases' env_parallel multiline ::: work env_parallel -S server multiline ::: work env_parallel --env multiline multiline ::: work env_parallel --env multiline -S server multiline ::: 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
Installation
Put this in $HOME
/.profile:
source env_parallel.pdksh
E.g. by doing:
echo 'source env_parallel.pdksh' >> $HOME/.profile
Supported use
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.
--session is supported.
- 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
sh
Installation
Put this in $HOME
/.profile:
. env_parallel.sh
E.g. by doing:
echo '. env_parallel.sh' >> $HOME/.profile
Supported use
--env is supported to export only the variable, or alias with the given name. Multiple --envs can be given.
--session is supported.
- aliases
sh does not support aliases.
- 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
sh does not support arrays.
tcsh (beta testing)
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`' >> $HOME/.tcshrc
Supported use
--env is supported to export only the variable, alias, or array with the given name. Multiple --envs can be given.
- aliases
alias myecho 'echo aliases' env_parallel myecho ::: work env_parallel -S server myecho ::: work env_parallel --env myecho myecho ::: work env_parallel --env myecho -S server myecho ::: work
- functions
Not supported by tcsh.
- variables
set myvar=variables env_parallel echo '$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
Installation
Put this in $HOME
/.zshrc:
. env_parallel.zsh
E.g. by doing:
echo '. env_parallel.zsh' >> $HOME/.zshenv
Supported use
--env is supported to export only the variable, alias, function, or array with the given name. Multiple --envs can be given.
--session is supported.
- 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 alias multiline='echo multiline echo aliases' env_parallel multiline ::: work env_parallel -S server multiline ::: work env_parallel --env multiline multiline ::: work env_parallel --env multiline -S server multiline ::: 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 env_parallel for a publication please cite:
O. Tange (2018): GNU Parallel 2018, March 2018, ISBN 9781387509881, DOI: 10.5281/zenodo.1146014.
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) 2008-2010 Ole Tange, http://ole.tange.dk
Copyright (C) 2010-2024 Ole Tange, http://ole.tange.dk and Free Software Foundation, Inc.
License
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 LICENSES/GFDL-1.3-or-later.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 LICENCES/CC-BY-SA-4.0.txt
Dependencies
env_parallel uses GNU parallel.
See Also
parallel(1), ash(1), bash(1), csh(1), dash(1), fish(1), ksh(1), pdksh(1) tcsh(1), zsh(1).
Referenced By
parallel(1), parallel_examples(7), parset(1).