uniq Command
  
  
  Purpose
  
  Deletes repeated lines in a file.
  
   Syntax
  
  uniq [  -c |  -d |  -u ] [  -f Fields ] [  -s Characters ] [ 
  -Fields ] [  +Characters ] [ InFile [ OutFile ] ]
  
  Description
  
  The uniq command reads either standard input or the InFile
  parameter.  The command first compares adjacent lines, then re-
  moves the second and succeeding  duplications  of a line.  Dupli-
  cated lines must be adjacent.  (Before issuing the uniq command,
  use the  sort command to make all duplicate lines adjacent.) Fi-
  nally, the uniq command writes the resultant unique lines either
  to standard output or to the file specified by the OutFile param-
  eter.  The InFile and OutFile parameters must specify different
  files.
  
  The uniq command compares entire lines by default.  If the -f
  Fields or -Fields flag is specified, the uniq command ignores the
  number of fields specified by the Fields variable.  A field is a
  string  of characters separated from other character  strings  by
  one or more <blank> characters.  If the -s Characters or
  -Characters flag is specified, the uniq command ignores the
  number of characters specified by the Characters variable.
  Values specified for the Fields and Characters variables must be
  positive decimal integers.
  
  The current National Language environment determines the <blank>
  characters used by the -f flag and it also determines how the -s
  flag interprets bytes as a character.
  
  The uniq command exits with a value of 0 if successful.  Other-
  wise, it exits with a value greater than 0.
  
  Flags
  
  -c	Precedes each output line with a count of the number of times
  each line appears in the file.  This flag supersedes  -d and  -u.
  
  -d	Displays only the repeated lines.
  
  -f Fields	Ignores the number of fields specified by the Fields
  variable.  This flag is equivalent to the -Fields flag.
  
  -u	Displays only the unrepeated lines.
  
  -s Characters	Ignores the number of characters specified by the
  Characters variable.  If both the -f and -s flags are specified,
  the uniq command ignores the number of characters specified by
  the -s Characters flag starting in the field following the fields
  specified by the -f Fields flag.  This flag is equivalent to the
  +Characters flag.
  
  -Fields	Ignores the number of fields specified by the Fields var-
  iable.  This flag is equivalent to the -f Fields flag.
  
  +Characters	Ignores the number of characters specified by the
  Characters variable.  If both the -Fields and +Characters flags
  are specified, the uniq command ignores the number of characters
  specified by the +Characters flag starting in the field following
  the fields specified by the -Fields flag.  This flag is
  equivalent to the -s Characters flag.
  
  Exit Status
  
  This command returns the following exit values:
  
  0	The command ran successfully.
  
  >0	An error occurred.
  
  Examples
  
  To delete repeated lines in a file named fruit and save it to a
  file named newfruit, enter:
  
  uniq fruit newfruit
  
  If the fruit file contains the following lines:
  
  apples
  apples
  peaches
  pears
  bananas
  cherries
  cherries
  
  then the newfruit file will contain the following lines after you
  run the uniq command:
  
  apples
  peaches
  pears
  bananas
  cherries
  
  Implementation Specifics
  
  This command is part of Base Operating System (BOS) Runtime.
  
  Files
  
  /usr/bin/uniq	Contains the uniq command.
  
  Related Information
  
  The  comm command,  sort command.