PARCAT

Section: parallel (1)
Updated: 2019-03-09
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NAME

parcat - cat files or fifos in parallel  

SYNOPSIS

parcat [--rm] [-#] file(s) [-#] file(s)  

DESCRIPTION

GNU parcat reads files or fifos in parallel. It writes full lines so there will be no problem with mixed-half-lines which you risk if you use:

   (cat file1 & cat file2 &) | ...

Arguments can be given on the command line or passed in on stdin (standard input).  

OPTIONS

-#
Arguments following this will be sent to the file descriptor #. E.g.

  parcat -1 stdout1 stdout2 -2 stderr1 stderr2

will send stdout1 and stdout2 to stdout (standard output = file descriptor 1), and send stderr1 and stderr2 to stderr (standard error = file descriptor 2).

--rm
Remove files after opening. As soon as the files are opened, unlink the files.
 

EXAMPLES

 

Simple line buffered output

GNU parallel saves output to tempfiles. If the amount of data is bigger than the free disk space, then you can use this technique to do line buffering without saving to disk:

  mkfifo slot-{1..5}
  seq 10000000 | parallel -j5 --round --pipe 'cat > slot-{%}' &
  parcat slot-{1..5} | wc

 

REPORTING BUGS

GNU parcat is part of GNU parallel. Report bugs to <bug-parallel@gnu.org>.  

AUTHOR

Copyright (C) 2016-2019 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 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

GNU parcat uses Perl.  

SEE ALSO

cat(1), parallel(1)


 

Index

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
Simple line buffered output
REPORTING BUGS
AUTHOR
LICENSE
Documentation license I
Documentation license II
DEPENDENCIES
SEE ALSO
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