JOIN(1)

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

SYNOPSIS
       join  [-a  1|2]  [-v  1|2]  [-e  empty-string]  [-o field-
       list...] [-t char] [-j[1|2] field] [-1 field]  [-2  field]
       file1 file2
       join {--help,--version}

DESCRIPTION
       This  documentation  is no longer being maintained and may
       be inaccurate or incomplete.  The Texinfo documentation is
       now the authoritative source.

       This  manual page documents the GNU version of join.  join
       prints to the standard output a  line  for  each  pair  of
       input  lines,  one  each  from  file1 and file2, that have
       identical join fields.  Either filename (but not both) can
       be  `-',  meaning  the  standard  input.   file1 and file2
       should be already sorted in increasing order (not  numeri-
       cally)  on the join fields; unless the -t option is given,
       they should be sorted ignoring blanks at the start of  the
       line, as sort does when given the -b option.

       The  defaults  are:  the  join field is the first field in
       each line; fields in the input are  separated  by  one  or
       more  blanks,  with  leading  blanks  on the line ignored;
       fields in the output are separated by a space; each output
       line consists of the join field, the remaining fields from
       file1, then the remaining fields from file2.

   OPTIONS
       -a file-number
              Print a line for each unpairable line in file file-
              number  (either  1 or 2), in addition to the normal
              output.

       -e string
              Replace empty output fields (those that are missing
              in the input) with string.

       -1, -j1 field
              Join on field field (a positive integer) of file 1.

       -2, -j2 field
              Join on field field (a positive integer) of file 2.

       -j field
              Equivalent to -1 field -2 field.

       -o field-list...
              Construct  each output line according to the format
              in field-list.  Each element in field-list consists
              of  a  file number (either 1 or 2), a period, and a
              field number (a positive integer).  The elements in
              the list are separated by commas or blanks.  Multi-
              ple field-list arguments can be given after a  sin-
              gle  -o  option; the values of all lists given with
              -o are concatenated together.

       -t char
              Use character char as the input  and  output  field
              separator.

       -v file-number
              Print a line for each unpairable line in file file-
              number (either 1 or 2), instead of the normal  out-
              put.

       In  addition,  when  GNU  join is invoked with exactly one
       argument, the following options are recognized:

       --help Print a usage message on standard output  and  exit
              successfully.

       --version
              Print  version  information on standard output then
              exit successfully.