parcat - cat files or fifos in parallel
parcat [--rm] [-#] file(s) [-#] file(s)
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).
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).
Remove files after opening. As soon as the files are opened, unlink the files.
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
GNU parcat is part of GNU parallel. Report bugs to <firstname.lastname@example.org>.
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GNU parcat uses Perl.