parcat(1)

1PARCAT(1)                          parallel                          PARCAT(1)
2
3
4

NAME

6       parcat - cat files or fifos in parallel
7

SYNOPSIS

9       parcat [--rm] [-#] file(s) [-#] file(s)
10

DESCRIPTION

12       GNU parcat reads files or fifos in parallel. It writes full lines so
13       there will be no problem with mixed-half-lines which you risk if you
14       use:
15
16          (cat file1 & cat file2 &) | ...
17
18       It is faster than doing:
19
20          parallel -j0 --lb cat ::: file*
21
22       Arguments can be given on the command line or passed in on stdin
23       (standard input).
24

OPTIONS

26       -#       Arguments following this will be sent to the file descriptor
27                #. E.g.
28
29                  parcat -1 stdout1 stdout2 -2 stderr1 stderr2
30
31                will send stdout1 and stdout2 to stdout (standard output =
32                file descriptor 1), and send stderr1 and stderr2 to stderr
33                (standard error = file descriptor 2).
34
35       --rm     Remove files after opening. As soon as the files are opened,
36                unlink the files.
37

EXAMPLES

39   Simple line buffered output
40       traceroute will often print half a line. If run in parallel, two
41       instances may half-lines of their output. This can be avoided by saving
42       the output to a fifo and then using parcat to read the two fifos in
43       parallel:
44
45         mkfifo freenetproject.org.fifo tange.dk.fifo
46         traceroute freenetproject.org > freenetproject.org.fifo &
47         traceroute tange.dk > tange.dk.fifo &
48         parcat --rm *fifo
49

REPORTING BUGS

51       GNU parcat is part of GNU parallel. Report bugs to
52       <bug-parallel@gnu.org>.
53

AUTHOR

55       Copyright (C) 2016-2020 Ole Tange, http://ole.tange.dk and Free
56       Software Foundation, Inc.
57

LICENSE

59       This program is free software; you can redistribute it and/or modify it
60       under the terms of the GNU General Public License as published by the
61       Free Software Foundation; either version 3 of the License, or at your
62       option any later version.
63
64       This program is distributed in the hope that it will be useful, but
65       WITHOUT ANY WARRANTY; without even the implied warranty of
66       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
67       General Public License for more details.
68
69       You should have received a copy of the GNU General Public License along
70       with this program.  If not, see <http://www.gnu.org/licenses/>.
71
72   Documentation license I
73       Permission is granted to copy, distribute and/or modify this
74       documentation under the terms of the GNU Free Documentation License,
75       Version 1.3 or any later version published by the Free Software
76       Foundation; with no Invariant Sections, with no Front-Cover Texts, and
77       with no Back-Cover Texts.  A copy of the license is included in the
78       file fdl.txt.
79
80   Documentation license II
81       You are free:
82
83       to Share to copy, distribute and transmit the work
84
85       to Remix to adapt the work
86
87       Under the following conditions:
88
89       Attribution
90                You must attribute the work in the manner specified by the
91                author or licensor (but not in any way that suggests that they
92                endorse you or your use of the work).
93
94       Share Alike
95                If you alter, transform, or build upon this work, you may
96                distribute the resulting work only under the same, similar or
97                a compatible license.
98
99       With the understanding that:
100
101       Waiver   Any of the above conditions can be waived if you get
102                permission from the copyright holder.
103
104       Public Domain
105                Where the work or any of its elements is in the public domain
106                under applicable law, that status is in no way affected by the
107                license.
108
109       Other Rights
110                In no way are any of the following rights affected by the
111                license:
112
113                •        Your fair dealing or fair use rights, or other
114                         applicable copyright exceptions and limitations;
115
116                •        The author's moral rights;
117
118                •        Rights other persons may have either in the work
119                         itself or in how the work is used, such as publicity
120                         or privacy rights.
121
122       Notice   For any reuse or distribution, you must make clear to others
123                the license terms of this work.
124
125       A copy of the full license is included in the file as cc-by-sa.txt.
126

DEPENDENCIES

128       GNU parcat uses Perl.
129