unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (OSF1-V5.1-alpha)
Page:
Section:
Apropos / Subsearch:
optional field



uniq(1)								      uniq(1)



NAME

  uniq - Removes or lists repeated lines in a file

SYNOPSIS

  Current Syntax


  uniq [-cdu] [-f fields] [-s chars] [input-file [output-file]]

  Obsolescent Syntax


  uniq [-cdu] [-fields]	[+chars] [input-file [output-file]]

  The uniq command reads from the specified input_file,	compares adjacent
  lines, removes the second and	succeeding occurrences of a line, and writes
  to standard output.

STANDARDS

  Interfaces documented	on this	reference page conform to industry standards
  as follows:

  uniq:	 XCU5.0

  Refer	to the standards(5) reference page for more information	about indus-
  try standards	and associated tags.

OPTIONS

  -c  Precedes each output line	with a count of	the number of times each line
      appears in the file.  This option	supersedes the -d and -u options.

  -d  Displays repeated	lines only.

  -f fields
      Ignores the first	fields fields on each input line when doing comparis-
      ons, where fields	is a positive decimal integer.	A field	is the maxi-
      mal string matched by the	basic regular expression:


	   [[:blank:]]*[^[:blank:]]*

      If the fields argument specifies more fields than	appear on an input
      line, a null string is used for comparisons.

  -s chars
      Ignores the specified number of characters when doing comparisons.  The
      chars argument is	a positive decimal integer.

      If specified with	the -f option, the first chars characters after	the
      first fields fields are ignored.	If the chars argument specifies	more
      characters than remain on	an input line, uniq uses a null	string for
      comparison.

  -u  Displays unique lines only.

  -fields
      Equivalent to -f fields.	(Obsolescent)

  +chars
      Equivalent to -s chars.  (Obsolescent)

OPERANDS

  input_file
      A	pathname for the input file.

      If this operand is omitted or specified as -, then standard input	is
      read.

  output_file
      A	pathname for the output	file.

      If this operand is omitted, then standard	output is written.

DESCRIPTION

  The input_file and output_file arguments must	be different files.  If	the
  input_file operand is	not specified, or if it	is -, uniq uses	standard
  input.

  Repeated lines must be on consecutive	lines to be found.  You	can arrange
  them with the	sort command before processing.

EXAMPLES

  To delete repeated lines in the following file called	fruit and save it to
  a file named newfruit, enter:

       uniq fruit newfruit

  The file fruit contains the following	lines:

       apples
       apples
       bananas
       cherries
       cherries
       peaches
       pears

  The file newfruit contains the following lines:

       apples
       bananas
       cherries
       peaches
       pears









EXIT STATUS

  The following	exit values are	returned:

  0   Successful completion.

  >>0  An error occurred.

ENVIRONMENT VARIABLES

  The following	environment variables affect the execution of uniq:

  LANG
      Provides a default value for the internationalization variables that
      are unset	or null. If LANG is unset or null, the corresponding value
      from the default locale is used.	If any of the internationalization
      variables	contain	an invalid setting, the	utility	behaves	as if none of
      the variables had	been defined.

  LC_ALL
      If set to	a non-empty string value, overrides the	values of all the
      other internationalization variables.

  LC_CTYPE
      Determines the locale for	the interpretation of sequences	of bytes of
      text data	as characters (for example, single-byte	as opposed to multi-
      byte characters in arguments).

  LC_MESSAGES
      Determines the locale for	the format and contents	of diagnostic mes-
      sages written to standard	error.

  NLSPATH
      Determines the location of message catalogues for	the processing of
      LC_MESSAGES.

SEE ALSO

  Commands:  comm(1), sort(1)

  Standards:  standards(5)