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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