AT&T UNIX™PC Unix System V Users Manual - tenox

JOIN ( 1 ) JOIN ( 1 )
NAME
join - relational database operator
SYNOPSIS
join [ options ] filel file2
DESCRIPTION
Join forms, on the standard output, a join of the two relations
specified by the lines of file1 and file2. If file1 is -, the standard
input is used.
File1 and file2 must be sorted in increasing ASCII collating
sequence on the fields on which they are to be joined, normally the
first in each line.
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.
Fields are normally separated by blank, tab or new-line. In this
case, multiple separators count as one, and leading separators are
discarded.
These options are recognized:
-an In addition to the normal output, produce a line for
each unpairable line in file n, where n is 1 or 2.
-e s Replace empty output fields by string s.
-j n m Join on the m th field of file n. If n is missing, use the
m th field in each file.
-o list Each output line comprises 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.
-tc Use character c as a separator (tab character). Every
appearance of c in a line is significant.
SEE ALSO
awk( l), comm(l), sort(l).
BUGS
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(l) are wildly
incongruous.
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