JOIN(1) 						   User Commands						   JOIN(1)



NAME
       join - join lines of two files on a common field

SYNOPSIS
       join [OPTION]... FILE1 FILE2

DESCRIPTION
       For  each  pair	of input lines with identical join fields, write a line to standard output.  The default join field is the
       first, delimited by whitespace.	When FILE1 or FILE2 (not both) is -, read standard input.

       -a FILENUM
	      print unpairable lines coming from file FILENUM, where FILENUM is 1 or 2, corresponding to FILE1 or FILE2

       -e EMPTY
	      replace missing input fields with EMPTY

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

       -j FIELD
	      equivalent to `-1 FIELD -2 FIELD'

       -o FORMAT
	      obey FORMAT while constructing output line

       -t CHAR
	      use CHAR as input and output field separator

       -v FILENUM
	      like -a FILENUM, but suppress joined output lines

       -1 FIELD
	      join on this FIELD of file 1

       -2 FIELD
	      join on this FIELD of file 2

       --check-order
	      check that the input is correctly sorted, even if all input lines are pairable

       --nocheck-order
	      do not check that the input is correctly sorted

       --header
	      treat the first line in each file as field headers, print them without trying to pair them

       --help display this help and exit

       --version
	      output version information and exit

       Unless -t CHAR is given, leading blanks separate fields and are ignored, else fields are separated by CHAR.  Any FIELD is a
       field  number counted from 1.  FORMAT is one or more comma or blank separated specifications, each being `FILENUM.FIELD' or
       `0'.  Default FORMAT outputs the join field, the remaining fields from FILE1, the remaining fields from	FILE2,	all  sepa‐
       rated  by  CHAR.   If FORMAT is the keyword 'auto', then the first line of each file determines the number of fields output
       for each line.

       Important: FILE1 and FILE2 must be sorted on the join fields.  E.g., use ` sort -k 1b,1 ' if `join' has no options, or  use
       ` join -t '' ' if `sort' has no options.  Note, comparisons honor the rules specified by `LC_COLLATE'.  If the input is not
       sorted and some lines cannot be joined, a warning message will be given.

AUTHOR
       Written by Mike Haertel.

REPORTING BUGS
       Report join bugs to bug-coreutils@gnu.org
       GNU coreutils home page: 
       General help using GNU software: 
       Report join translation bugs to 

COPYRIGHT
       Copyright   ©   2011   Free   Software	Foundation,   Inc.    License	GPLv3+:   GNU	GPL    version	  3    or    later
       .
       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), uniq(1)

       The full documentation for join is maintained as a Texinfo manual.  If the info and join programs are properly installed at
       your site, the command

	      info coreutils 'join invocation'

       should give you access to the complete manual.



GNU coreutils 8.12.197-032bb				  September 2011						   JOIN(1)