JOIN(1)                  DOMAIN/IX SYS5                   JOIN(1)



NAME
     join - relational database operator

USAGE
     join [ options ] file1 file2

DESCRIPTION
     Join forms, on the standard output, a union between the two
     relations specified by the lines of file1 and file2.  If you
     use a dash (-) in place of file1, the standard input is
     used.  File1 and file2 must be sorted in increasing ASCII
     collating sequence in the fields where they are to be joined
     (normally, the first in each line).

     One line in the output for each pair of lines in file1 and
     file2 will have identical join fields.  The output line nor-
     mally consists of the common field, then the remainder of
     the line from file1, and finally, the remainder of the line
     from file2.

     The default input field separators are blank, tab, or new-
     line.  Multiple separators usually count as one field
     separator, and leading separators are ignored.  The default
     output field separator is a blank.

OPTIONS
     Some of the options below use the argument n.  This argument
     should be a 1 or 2 referring to either file1 or file2,
     respectively.

     -an       In addition to the normal output, produce a line
               for each line that cannot be paired in file n,
               where n is 1 or 2.

     -e s      Replace empty output fields by string s.

     -jn m     Join on the mth field of file n.  If n is missing,
               use the mth field in each file.  Fields are num-
               bered starting with one.

     -o list   Let each output line comprise the fields specified
               in list, each element of which has the form n.m,
               where n is a file number and m is a field number.
               Do not print the common field unless specifically
               requested.

     -tc       Use character c as a separator (tab character) for
               both input and output.  Every appearance of c in a
               line is significant.




Printed 12/4/86                                            JOIN-1

JOIN(1)                  DOMAIN/IX SYS5                   JOIN(1)



EXAMPLE
     To join the fourth field of both file1 and file2, use this
     command:

           # join -j1 4 -j2 4 file1 file2

CAUTIONS
     With default field separation, the collating sequence is
     that of sort -b; with -t, the sequence is a plain sort.

     The conventions used by join conflict with those used by
     sort(1), comm(1), uniq(1), and awk(1).

     Numeric filenames may cause problems when you use the -o
     option just before listing filenames.

RELATED INFORMATION
     awk(1), comm(1), sort(1), uniq(1).



































JOIN-2                                            Printed 12/4/86