
****
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:


.. code-block:: perl

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


It is faster than doing:


.. code-block:: perl

    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.
 
 
 .. code-block:: perl
 
    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:


.. code-block:: perl

   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) 2016-2021 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
 


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- \ **Attribution**\ 
 
 You must attribute the work in the manner specified by the author or
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 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
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- \ **Other Rights**\ 
 
 In no way are any of the following rights affected by the license:
 
 
 - \*
  
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 - \*
  
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- \ **Notice**\ 
 
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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)

