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 blanks.

       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
	      line delimiter is NUL, 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  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 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.

AUTHOR

       Written by Mike Haertel.

REPORTING BUGS

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

COPYRIGHT

       Copyright (C) 2017 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)

       Full documentation at: <http://www.gnu.org/software/coreutils/join>
       or available locally via: info '(coreutils) join invocation'

GNU coreutils 8.28						   January 2018 							   JOIN(1)