comm(1) | comm(1) |
NAME
comm - select or reject lines common to two sorted ®les
SYNOPSIS
comm
DESCRIPTION
comm reads ®le1 and ®le2, which should be ordered in increasing collating sequence (see sort(1) and Environment Variables below), and produces a
Column 1: Lines that appear only in ®le1,
Column 2: Lines that appear only in ®le2,
Column 3: Lines that appear in both ®les.
If - is used for ®le1 or ®le2, the standard input is used.
Options 1, 2, or 3 suppress printing of the corresponding column. Thus comm
EXTERNAL INFLUENCES
Environment Variables
LC_COLLATE determines the collating sequence comm expects from the input ®les.
LC_MESSAGES determines the language in which messages are displayed.
If LC_MESSAGES is not speci®ed in the environment or is set to the empty string, the value of LANG determines the language in which messages are displayed. If LC_COLLATE is not speci®ed in the environment or is set to the empty string, the value of LANG is used as a default. If LANG is not speci®ed or is set to the empty string, a default of ``C'' (see lang(5)) is used instead of LANG. If any internationalization variable contains an invalid setting, comm behaves as if all internationalization variables are set to ``C''. See environ(5).
International Code Set Support
Single- and
EXAMPLES
The following examples assume that file1 and file2 have been ordered in the collating sequence de®ned by the LC_COLLATE or LANG environment variable.
Print all lines common to file1 and file2 (in other words, print column 3):
comm
Print all lines that appear in file1 but not in file2 (in other words, print column 1):
comm
Print all lines that appear in file2 but not in file1 (in other words, print column 2):
comm
SEE ALSO
cmp(1), diff(1), sdiff(1), sort(1), uniq(1).
STANDARDS CONFORMANCE
comm: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
c
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