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
	      also  print unpairable lines 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

       -z, --zero-terminated
	      end lines with 0 byte, not newline

       --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 num-
       ber counted from 1.  FORMAT is one or more  comma  or  blank  separated
       specifications, each being 'FILENUM.FIELD' or '0'.  Default FORMAT out-
       puts the join field, the remaining fields  from	FILE1,	the  remaining
       fields  from  FILE2,  all  separated 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.

       GNU  coreutils  online  help:  <http://www.gnu.org/software/coreutils/>
       Report join translation bugs to <http://translationproject.org/team/>

AUTHOR
       Written by Mike Haertel.

COPYRIGHT
       Copyright (C) 2013 Free Software Foundation, Inc.  License GPLv3+:  GNU
       GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       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 8.22		 February 2016			       JOIN(1)