uniq(1) User Commands uniq(1)NAMEuniq - report or filter out repeated lines in a file
SYNOPSISuniq [-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 suc‐
ceeding copies of repeated adjacent input lines will not be written.
Repeated lines in the input will not be detected if they are not adja‐
cent.
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 compar‐
isons, 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 com‐
parison.
-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 out‐
put_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 out‐
puts 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 attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWesu │
├─────────────────────────────┼─────────────────────────────┤
│CSI │Enabled │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOcomm(1), pack(1), pcat(1), sort(1), uncompress(1), attributes(5), envi‐
ron(5), standards(5)SunOS 5.10 20 Dec 1996 uniq(1)
