join(1)join(1)NAMEjoin - relational database operator
SYNOPSIS
[options] file1 file2
DESCRIPTION
forms, on the standard output, a join of the two relations specified by
the lines of file1 and file2. If file1 or file2 is the standard input
is used.
file1 and file2 must be sorted in increasing collating sequence (see
Environment Variables below) on the fields on which they are to be
joined; normally the first in each line.
The output contains one line for each pair of lines in file1 and file2
that have identical join fields. The output line normally consists of
the common field followed by the rest of the line from file1, then the
rest of the line from file2.
The default input field separators are space, tab, or new-line. In
this case, multiple separators count as one field separator, and lead‐
ing separators are ignored. The default output field separator is a
space.
Some of the below options use the argument n. This argument should be
a or a referring to either file1 or file2, respectively.
Options
In addition to the normal output,
produce a line for each unpairable line in file n, where n
is or
Replace empty output fields by string
s.
Join on field
m of both files. The argument m must be delimited by space
characters. This option and the following two are provided
for backward compatibility. Use of the and options ( see
below ) is recommended for portability.
Join on field
m of file1.
Join on field
m of file2.
Each output line comprises the fields specified in
list, each element of which has the form where n is a file
number and m is a field number. The common field is not
printed unless specifically requested.
Use 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.
Instead of the default output,
produce a line only for each unpairable line in file_num‐
ber, where file_number is or
Join on field
f of file 1. Fields are numbered starting with 1.
Join on field
f of file 2. Fields are numbered starting with 1.
EXTERNAL INFLUENCES
Environment Variables
determines the collating sequence expects from input files.
determines the alternative blank character as an input field separator,
and the interpretation of data within files as single and/or multi-byte
characters. also determines whether the separator defined through the
option is a single- or multi-byte character.
If or is not specified in the environment or is set to the empty
string, the value of is used as a default for each unspecified or empty
variable. If is not specified or is set to the empty string, a default
of ``C'' (see lang(5)) is used instead of If any internationalization
variable contains an invalid setting, behaves as if all international‐
ization variables are set to ``C'' (see environ(5)).
International Code Set Support
Single- and multi-byte character code sets are supported with the
exception that multi-byte-character file names are not supported.
EXAMPLES
The following command line joins 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 have
been sorted in the collating sequence defined by the or environment
variable on the group ID fields.
The following command produces an output consisting all possible combi‐
nations of lines that have identical first fields in the two sorted
files sf1 and sf2, with each line consisting of the first and third
fields from and the second and fourth fields from
WARNINGS
With default field separation, the collating sequence is that of with
the sequence is that of a plain sort.
The conventions of and are incongruous.
Numeric filenames may cause conflict when the option is used immedi‐
ately before listing filenames.
AUTHOR
was developed by OSF and HP.
SEE ALSOawk(1), comm(1), sort(1), uniq(1).
STANDARDS CONFORMANCEjoin(1)
