uniq(1) manual page
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uniq - report or filter out repeated lines in a file
uniq
[-c|-d|-u] [-f fields] [-s char] [input_file [output_file]]
uniq [-c|-d|-u] [-n] [+m] [input_file [output_file]]
SUNWesu
The uniq utility will read an input file comparing adjacent lines, and
write one copy of each input line on the output. The second and succeeding
copies of repeated adjacent input lines will not be written.
Repeated lines
in the input will not be detected if they are not adjacent.
The following
options are supported:
- -c
- Precede each output line with a count of the number
of times the line occurred in the input.
- -d
- Suppress the writing of lines
that are not repeated in the input.
- -f fields
- Ignore the first fields fields
on each input line when doing comparisons, where fields is a positive decimal
integer. A field is the maximal string matched by the basic regular expression:
[[:blank:]]*[^[:blank:]]*
If fields specifies more fields than appear on
an input line, a null string will be used for comparison.
- -s chars
- Ignore
the first chars characters when doing comparisons, where chars is a positive
decimal integer. If specified in conjunction with the -f option, the first
chars characters after the first fields fields will be ignored. If chars
specifies more characters than remain on an input line, a null string will
be used for comparison.
- -u
- Suppress the writing of lines that are repeated
in the input.
- -n
- Equivalent to -f fields with fields set to n.
- +m
- Equivalent
to -s chars with chars set to m.
The following operands are supported:
- input_file
- A path name of the input file. If input_file is not specified,
or if the input_file is -, the standard input will be used.
- output_file
- A
path name of the output file. If output_file is not specified, the standard
output will be used. The results are unspecified if the file named by output_file
is the file named by input_file.
The following example lists the contents of the uniq.test file
and outputs a copy of the repeated lines.
example% cat uniq.test
This is a test.
This is a test.
TEST.
Computer.
TEST.
TEST.
Software.
example% uniq -d uniq.test
This is a test.
TEST.
example%
The next example outputs just those lines that are not repeated in the
uniq.test file.
example% uniq -u uniq.test
TEST.
Computer.
Software.
example%
The last example outputs a report with each line preceded by a count of
the number of times each line occurred in the file.
example% uniq -c uniq.test
2 This is a test.
1 TEST.
1 Computer.
2 TEST.
1 Software.
example%
See environ(5)
for descriptions of the following environment
variables that affect the execution of uniq: LC_CTYPE, LC_MESSAGES, and
NLSPATH.
The following exit values are returned:
- Successful completion.
- >0
- An error occurred.
comm(1)
, pack(1)
, pcat(1)
, uncompress(1)
, sort(1)
,
environ(5)
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