NAME

       uniq - report or omit repeated lines

SYNOPSIS

       uniq [OPTION]... [INPUT [OUTPUT]]

DESCRIPTION

       Filter  adjacent  matching  lines  from  INPUT  (or standard input), writing to OUTPUT (or
       standard output).

       With no options, matching lines are merged to the first occurrence.

       Mandatory arguments to long options are mandatory for short options too.

       -c, --count
              prefix lines by the number of occurrences

       -d, --repeated
              only print duplicate lines, one for each group

       -D     print all duplicate lines

       --all-repeated[=METHOD]
              like    -D,    but    allow    separating    groups    with    an    empty    line;
              METHOD={none(default),prepend,separate}

       -f, --skip-fields=N
              avoid comparing the first N fields

       --group[=METHOD]
              show     all     items,     separating     groups     with     an    empty    line;
              METHOD={separate(default),prepend,append,both}

       -i, --ignore-case
              ignore differences in case when comparing

       -s, --skip-chars=N
              avoid comparing the first N characters

       -u, --unique
              only print unique lines

       -z, --zero-terminated
              line delimiter is NUL, not newline

       -w, --check-chars=N
              compare no more than N characters in lines

       --help display this help and exit

       --version
              output version information and exit

       A field is a run of blanks  (usually  spaces  and/or  TABs),  then  non-blank  characters.
       Fields are skipped before chars.

       Note:  'uniq'  does  not  detect repeated lines unless they are adjacent.  You may want to
       sort the input first, or use 'sort -u' without 'uniq'.

AUTHOR

       Written by Richard M. Stallman and David MacKenzie.

REPORTING BUGS

       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT

       Copyright © 2023 Free Software Foundation, Inc.  License GPLv3+:  GNU  GPL  version  3  or
       later <https://gnu.org/licenses/gpl.html>.
       This  is free software: you are free to change and redistribute it.  There is NO WARRANTY,
       to the extent permitted by law.

SEE ALSO

       comm(1), join(1), sort(1)

       Full documentation <https://www.gnu.org/software/coreutils/uniq>
       or available locally via: info '(coreutils) uniq invocation'