uniq - report repeated lines in a file
uniq [-udc [-f fields] [-s chars] [input_file [output_file]]
uniq reads the input text file input_file, comparing adjacent lines,
and copies the result to output_file. If input_file is not specified,
the standard input and standard output are used. If input_file is
specified, but output_file is not, results are printed to standard
output. input_file and output_file must not be the same file.
uniq recognizes the following options when comparing adjacent lines:
-u Print only those lines that are not repeated in the
-d Print one copy only of each repeated line in the input
-c Generate an output report in default style except that
each line is preceded by a count of the number of times
it occurred. If this option is specified, the -u and -d
options are ignored if either or both are also present.
If none of the options u, d, or c are present, uniq prints the results
of the union of the -u and -d options, producing a copy of the
original input file with the second and succeeding copies of any
repeated lines removed. (Note that repeated lines must be adjacent in
order to be found - see sort(1)).
Two options are provided for skipping an initial portion of each line
when making comparisons:
-f fields Ignore the first fields fields, together with any
blanks before each. fields is a positive decimal
integer. A field is defined as a string of non-
space, non-tab characters separated by tabs and/or
spaces from its neighbors.
-s chars Ignore the first chars characters. chars is a
positive decimal integer. Each line in the input
is assumed to be terminated with a new line
character for purposes of comparison. Fields are
skipped before characters.
Hewlett-Packard Company - 1 - HP-UX Release 11i: November 2000
LC_COLLATE must be equal to the value it had when the input files were
LC_CTYPE determines the interpretation of text within files as single-
and/or multi-byte characters, and defines a space character when the
-f or -s option is used.
LC_MESSAGES determines the language in which messages are displayed.
If LC_COLLATE, LC_CTYPE or LC_MESSAGES is not specified in the
environment or is set to the empty string, the value of LANG is used
as a default for each unspecified or empty variable. If LANG is not
specified 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, uniq behaves as if all
internationalization variables are set to "C". See environ(5).
International Code Set Support
Single- and multi-byte character code sets are supported.
Exit values are:
0 Successful completion.
>>>>0 Error condition occurred.
uniq was developed by OSF and HP.
uniq: SVID2, SVID3, XPG2, XPG3, XPG4, POSIX.2
Hewlett-Packard Company - 2 - HP-UX Release 11i: November 2000