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 &) | ...

       It is faster than doing:

          parallel -j0 --lb cat ::: file*

       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
       traceroute will often print half a line. If run in parallel, two instances may half-lines
       of their output. This can be avoided by saving the output to a fifo and then using parcat
       to read the two fifos in parallel:

         mkfifo freenetproject.org.fifo tange.dk.fifo
         traceroute freenetproject.org > freenetproject.org.fifo &
         traceroute tange.dk > tange.dk.fifo &
         parcat --rm *fifo

REPORTING BUGS

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

AUTHOR

       Copyright (C) 2016-2024 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

       GNU parcat uses Perl.

SEE ALSO

       cat(1), parallel(1)