uniq - remove duplicate lines from a sorted file

SYNOPSIS

       uniq  [-cdu]  [-f  skip-fields] [-s skip-chars] [-w check-
       chars]    [-#skip-fields]     [+#skip-chars]     [--count]
       [--repeated]     [--unique]    [--skip-fields=skip-fields]
       [--skip-chars=skip-chars]      [--check-chars=check-chars]
       [--help] [--version] [infile] [outfile]

DESCRIPTION

       This  manual page documents the GNU version of uniq.  uniq
       prints the unique lines in a sorted file,  discarding  all
       but  one  of  a  run of matching lines.  It can optionally
       show only lines that appear exactly once,  or  lines  that
       appear more than once.  uniq requires sorted input because
       it compares only consecutive lines.

       If the output file is not specified, uniq  writes  to  the
       standard  output.   If the input file is not specified, it
       reads from the standard input.

   OPTIONS
       -u, --unique
              Only print unique lines.

       -d, --repeated
              Only print duplicate lines.

       -c, --count
              Print the number of times each line occurred  along
              with the line.

       -number, -f, --skip-fields=number
              In  this  option, number is an integer representing
              the number of fields to skip over  before  checking
              for  uniqueness.   The  first  number fields, along
              with any  blanks  found  before  number  fields  is
              reached,  are skipped over and not counted.  Fields
              are defined as  a  strings  of  non-space,  non-tab
              characters,  that  are separated from each other by
              spaces and tabs.

       +number, -s, --skip-chars=number
              In this option, number is an  integer  representing
              the number of characters to skip over before check-
              ing for uniqueness.  The first  number  characters,
              along  with  any blanks found before number charac-
              ters is reached, are skipped over and not  counted.
              If  you  use  both the field and character skipping
              options, fields are skipped over first.

       -w, --check-chars=number
              characters.  Normally the entire rest of the  lines
              are compared.

       --help Print  a  usage message and exit with a status code
              indicating success.

       --version
              Print version information on standard  output  then
              exit.