1 .\" $NetBSD: join.1,v 1.11 2003/03/31 01:55:23 perry Exp $
3 .\" Copyright (c) 1990, 1993
4 .\" The Regents of the University of California. All rights reserved.
6 .\" This code is derived from software contributed to Berkeley by
7 .\" the Institute of Electrical and Electronics Engineers, Inc.
9 .\" Redistribution and use in source and binary forms, with or without
10 .\" modification, are permitted provided that the following conditions
12 .\" 1. Redistributions of source code must retain the above copyright
13 .\" notice, this list of conditions and the following disclaimer.
14 .\" 2. Redistributions in binary form must reproduce the above copyright
15 .\" notice, this list of conditions and the following disclaimer in the
16 .\" documentation and/or other materials provided with the distribution.
17 .\" 3. Neither the name of the University nor the names of its contributors
18 .\" may be used to endorse or promote products derived from this software
19 .\" without specific prior written permission.
21 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 .\" from: @(#)join.1 8.3 (Berkeley) 4/28/95
34 .\" $NetBSD: join.1,v 1.11 2003/03/31 01:55:23 perry Exp $
41 .Nd relational database operator
46 .Fl a Ar file_number | Fl v Ar file_number
53 .Op Fl j Ar file_number field
63 The join utility performs an ``equality join'' on the specified files
64 and writes the result to the standard output.
65 The ``join field'' is the field in each file by which the files are compared.
66 The first field in each line is used by default.
67 There is one line in the output for each pair of lines in
71 which have identical join fields.
72 Each output line consists of the join field, the remaining fields from
74 and then the remaining fields from
77 The default field separators are tab and space characters.
78 In this case, multiple tabs and spaces count as a single field separator,
79 and leading tabs and spaces are ignored.
80 The default output field separator is a single space character.
82 Many of the options use file and field numbers.
83 Both file numbers and field numbers are 1 based, i.e. the first file on
84 the command line is file number 1 and the first field is field number 1.
85 The following options are available:
87 .It Fl a Ar file_number
88 In addition to the default output, produce a line for each unpairable
93 must not be preceded by a space; see the
97 Replace empty output fields with
102 option specifies the fields that will be output from each file for
103 each line with matching join fields.
107 .Ql file_number.field ,
113 The elements of list must be either comma (``,'') or whitespace separated.
114 (The latter requires quoting to protect it from the shell, or, a simpler
115 approach is to use multiple
121 as a field delimiter for both input and output.
124 in a line is significant.
125 .It Fl v Ar file_number
126 Do not display the default output, but display a line for each unpairable
133 may be specified at the same time.
144 When the default field delimiter characters are used, the files to be joined
145 should be ordered in the collating sequence of
149 option, on the fields on which they are to be joined, otherwise
151 may not report all field matches.
152 When the field delimiter characters are specified by the
154 option, the collating sequence should be the same as
160 If one of the arguments
164 is ``-'', the standard input is used.
168 utility exits 0 on success, and \*[Gt]0 if an error occurs.
170 For compatibility with historic versions of
172 the following options are available:
175 In addition to the default output, produce a line for each unpairable line
176 in both file 1 and file 2.
177 (To distinguish between this and
178 .Fl a Ar file_number ,
180 currently requires that the latter not include any white space.)
192 field of both file 1 and file 2.
194 Historical implementations of
196 permitted multiple arguments to the
199 These arguments were of the form ``file_number.field_number'' as described
203 This has obvious difficulties in the presence of files named ``1.2''.
206 These options are available only so historic shell scripts don't require
207 modification and should not be used.
217 command is expected to be