join(1)                             CLIX                             join(1)



  NAME

    join - Relational database operator

  SYNOPSIS

    join [flags] file1 file2

  FLAGS

    -an       Produces a line for each unpairable line in file n, where n is 1
              or 2, in addition to the normal output.

    -e s      Replaces empty output fields with string s.

    -jn m     Joins on the mth field of file n.  If n is missing, join uses
              the mth field in each file.  Fields are numbered starting with
              1.

    -o list   Includes the fields specified in list in each output line.  Each
              element of list has the form n.m, where n is a file number and m
              is a field number.  The common field is not displayed unless
              specifically requested.

    -tc       Uses character c as a separator (tab character).  Every
              appearance of c in a line is significant.  The character c is
              used as the field separator for both input and output.

  DESCRIPTION

    The join command forms, on stdout, a join of the two relations specified
    by the lines of file1 and file2.  If file1 is -, stdin is used.

    File1 and file2 must be sorted in ascending ASCII collating sequence on
    the fields on which they are to be joined, normally the first in each line
    (see sort).

    There is one line in the output for each pair of lines in file1 and file2
    that have identical join fields.  The output line normally consists of the
    common field, then the rest of the line from file1, then the rest of the
    line from file2.

    The default input field separators are blank, tab, or newline.  In this
    case, multiple separators count as one field separator, and leading
    separators are ignored.  The default output field separator is a blank.

  EXAMPLES

    1.  The following command line will join the password file and the group
        file, matching on the numeric group ID, and outputting the login name,
        the group name and the login directory.  It is assumed that the files



  2/94 - Intergraph Corporation                                              1

  join(1)                             CLIX                             join(1)



        have been sorted in ASCII collating sequence on the group ID fields.

        join -j1 4 -j2 3 -o 1.1 2.1 1.6 -t: /etc/passwd /etc/group


  NOTES

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

    The conventions of join, sort, comm, uniq, and awk are wildly incongruous.

    Filenames that are numeric may cause conflict when the -o flag is used
    right before listing filenames.

  DIAGNOSTICS

    join: can't open file

    One of the files being joined does not have read permission or does not
    exist.

  EXIT VALUES

    If unsuccessful, join returns an exit value of 1.

  RELATED INFORMATION

    Commands: awk(1), comm(1), sort(1), uniq(1)

























  2                                              Intergraph Corporation - 2/94