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 separated by CHAR.
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: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report join translation bugs to <http://translationproject.org/team/>
COPYRIGHT
Copyright © 2010 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.