PARSET(1)

NAME
parset - set shell variables in parallel

SYNOPSIS
parset variablename [options for GNU Parallel]

env_parset variablename [options for GNU Parallel]

DESCRIPTION
parset is a shell function that puts the output from GNU parallel into shell variables.

env_parset is a shell function that puts the output from env_parallel into shell variables.

The parset and env_parset functions are defined as part of env_parallel.

If variablename is a single variable name, this will be treated as the destination variable. If the variable is defined as an associative array (using typeset -A myassoc), this will be used. Otherwise the variable will be made into a normal array.

If variablename contains multiple names separated by ',' or space, the names will be the destination variables. The number of names must be at least the number of jobs.

OPTIONS
Same as GNU parallel, but they are put after the destination variable.

SUPPORTED SHELLS

  Bash/Zsh/Ksh/Mksh
Examples

Put output into myarray:

  parset myarray seq 3 ::: 4 5 6
  echo "${myarray[1]}"

Put output into vars $seq, $pwd, $ls:

  parset "seq pwd ls" ::: "seq 10" pwd ls
  echo "$ls"

Put output into vars $seq, $pwd, $ls:

  into_vars=(seq pwd ls)
  parset "${into_vars[*]}" ::: "seq 10" pwd ls
  echo "$ls"

Put output into associative array myassoc (not supported for mksh):

  typeset -A myassoc
  parset myassoc seq ::: 4 5 ::: 6 7
  echo "${myassoc[4 7]}"

The commands to run can be an array:

  cmd=("echo first" "echo '<<joe  \"double  space\"  cartoon>>'" "pwd")
  parset data ::: "${cmd[@]}"
  echo "${data[1]}"
  echo "${data[2]}"

parset can read from stdin (standard input) if it is a file:

  parset res echo < parallel_input_file

but parset can not be part of a pipe. In particular this means it cannot read from a pipe or write to a pipe:

  seq 10 | parset res echo Does not work

but must instead use a tempfile:

  seq 10 > parallel_input
  parset res echo :::: parallel_input
  echo "${res[1]}"
  echo "${res[9]}"

or a FIFO:

  mkfifo input_fifo
  seq 30 > input_fifo &
  parset res echo :::: input_fifo
  echo "${res[1]}"
  echo "${res[29]}"

or Bash/Zsh/Ksh process substitution:

  parset res echo :::: <(seq 100)
  echo "${res[1]}"
  echo "${res[99]}"

Installation

Put this in the relevant $HOME/.bashrc or $HOME/.zshenv or $HOME/.kshrc:

  . `which env_parallel.bash`
  . `which env_parallel.zsh`
  source `which env_parallel.ksh`

E.g. by doing:

  echo '. `which env_parallel.bash`' >> $HOME/.bashrc
  echo '. `which env_parallel.zsh`' >> $HOME/.zshenv
  echo 'source `which env_parallel.ksh`' >> $HOME/.kshrc

or by doing:

  env_parallel --install

  ash/dash (FreeBSD's /bin/sh)
Examples

ash does not support arrays.

Put output into vars $seq, $pwd, $ls:

  parset "seq pwd ls" ::: "seq 10" pwd ls
  echo "$ls"

parset can read from stdin (standard input) if it is a file:

  parset res1,res2,res3 echo < parallel_input_file

but parset can not be part of a pipe. In particular this means it cannot read from a pipe or write to a pipe:

  seq 3 | parset res1,res2,res3 echo Does not work

but must instead use a tempfile:

  seq 3 > parallel_input
  parset res1,res2,res3 echo :::: parallel_input
  echo "$res1"
  echo "$res2"
  echo "$res3"

or a FIFO:

  mkfifo input_fifo
  seq 3 > input_fifo &
  parset res1,res2,res3 echo :::: input_fifo
  echo "$res1"
  echo "$res2"
  echo "$res3"

Installation

Put the relevant one of these into $HOME/.profile:

  . `which env_parallel.sh`
  . `which env_parallel.ash`
  . `which env_parallel.dash`

E.g. by doing:

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

or by doing:

  env_parallel --install

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) 2008-2010 Ole Tange, http://ole.tange.dk

Copyright (C) 2010-2023 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
parset uses GNU parallel.

SEE ALSO
parallel(1), env_parallel(1), bash(1).