uniq(1) [mojave man page]

UNIQ(1) 						    BSD General Commands Manual 						   UNIQ(1)

NAME

     uniq -- report or filter out repeated lines in a file

SYNOPSIS

     uniq [-c | -d | -u] [-i] [-f num] [-s chars] [input_file [output_file]]

DESCRIPTION

     The uniq utility reads the specified input_file comparing adjacent lines, and writes a copy of each unique input line to the output_file.	If
     input_file is a single dash ('-') or absent, the standard input is read.  If output_file is absent, standard output is used for output.  The
     second and succeeding copies of identical adjacent input lines are not written.  Repeated lines in the input will not be detected if they are
     not adjacent, so it may be necessary to sort the files first.

     The following options are available:

     -c      Precede each output line with the count of the number of times the line occurred in the input, followed by a single space.

     -d      Only output lines that are repeated in the input.

     -f num  Ignore the first num fields in each input line when doing comparisons.  A field is a string of non-blank characters separated from
	     adjacent fields by blanks.  Field numbers are one based, i.e., the first field is field one.

     -s chars
	     Ignore the first chars characters in each input line when doing comparisons.  If specified in conjunction with the -f option, the
	     first chars characters after the first num fields will be ignored.  Character numbers are one based, i.e., the first character is
	     character one.

     -u      Only output lines that are not repeated in the input.

     -i      Case insensitive comparison of lines.

ENVIRONMENT

     The LANG, LC_ALL, LC_COLLATE and LC_CTYPE environment variables affect the execution of uniq as described in environ(7).

EXIT STATUS

     The uniq utility exits 0 on success, and >0 if an error occurs.

COMPATIBILITY

     The historic +number and -number options have been deprecated but are still supported in this implementation.

SEE ALSO

     sort(1)

STANDARDS

     The uniq utility conforms to IEEE Std 1003.1-2001 (``POSIX.1'') as amended by Cor. 1-2002.

HISTORY

     A uniq command appeared in Version 3 AT&T UNIX.

BSD
								 December 17, 2009							       BSD

uniq(1) 						      General Commands Manual							   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 industry standards and associated tags.

OPTIONS

       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.
       Displays  repeated lines only.  Ignores the first fields fields on each input line when doing comparisons, where fields is a positive deci-
       mal integer.  A field is the maximal 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.  Ignores the spec-
	      ified 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 speci-
	      fies more characters than remain on an input line, uniq uses a null string for comparison.  Displays unique lines only.	Equivalent
	      to -f fields.  (Obsolescent) Equivalent to -s chars.  (Obsolescent)

OPERANDS

       A pathname for the input file.

	      If this operand is omitted or specified as -, then standard input is read.  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: Successful completion.  An error occurred.

ENVIRONMENT VARIABLES

       The following environment variables affect the execution of uniq: 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 vari-
       ables contain an invalid setting, the utility behaves as if none of the variables had been defined.  If set to a  non-empty  string  value,
       overrides  the  values of all the other internationalization variables.	Determines the locale for the interpretation of sequences of bytes
       of text data as characters (for example, single-byte as opposed to multibyte characters in arguments).  Determines the locale for the  for-
       mat  and  contents  of  diagnostic messages written to standard error.  Determines the location of message catalogues for the processing of
       LC_MESSAGES.

SEE ALSO

       Commands:  comm(1), sort(1)

       Standards:  standards(5)

																	   uniq(1)