uniq(1)
NAME
uniq - report or filter out repeated lines in a file
SYNOPSIS
uniq [-c | -d | -u] [-f fields] [-s char] [ input_file
[output_file]]
uniq [-c | -d | -u] [-n] [ + m] [ input_file
[output_file]]
DESCRIPTION
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.
OPTIONS
The following options are supported:
-c Precedes each output line with a count of the number
of times the line occurred in the input.
-d Suppresses the writing of lines that are not repeated
in the input.
-f fields
Ignores 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
Ignores the first chars characters when doing com-
parisons, 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 Suppresses 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.
OPERANDS
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.
EXAMPLES
Example 1: Using the uniq command
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%
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment
variables that affect the execution of uniq: LANG, LC_ALL,
LC_CTYPE, LC_MESSAGES, and NLSPATH.
EXIT STATUS
The following exit values are returned:
0 Successful completion.
>0 An error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWesu |
|_____________________________|_____________________________|
| CSI | Enabled |
|_____________________________|_____________________________|
| Interface Stability | Standard |
|_____________________________|_____________________________|
SEE ALSO
comm(1), pack(1), pcat(1), sort(1), uncompress(1), attri-
butes(5), environ(5), standards(5)
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