1.\" Copyright (c) 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)join.1 8.3 (Berkeley) 4/28/95 36.\" $FreeBSD$ 37.\" 38.Dd April 18, 2002 39.Dt JOIN 1 40.Os 41.Sh NAME 42.Nm join 43.Nd relational database operator 44.Sh SYNOPSIS 45.Nm 46.Oo 47.Fl a Ar file_number | Fl v Ar file_number 48.Oc 49.Op Fl e Ar string 50.Op Fl j Ar file_number field 51.Op Fl o Ar list 52.Bk -words 53.Ek 54.Op Fl t Ar char 55.Op Fl \&1 Ar field 56.Op Fl \&2 Ar field 57.Ar file1 58.Ar file2 59.Sh DESCRIPTION 60The 61.Nm 62utility performs an 63.Dq equality join 64on the specified files 65and writes the result to the standard output. 66The 67.Dq join field 68is the field in each file by which the files are compared. 69The first field in each line is used by default. 70There is one line in the output for each pair of lines in 71.Ar file1 72and 73.Ar file2 74which have identical join fields. 75Each output line consists of the join field, the remaining fields from 76.Ar file1 77and then the remaining fields from 78.Ar file2 . 79.Pp 80The default field separators are tab and space characters. 81In this case, multiple tabs and spaces count as a single field separator, 82and leading tabs and spaces are ignored. 83The default output field separator is a single space character. 84.Pp 85Many of the options use file and field numbers. 86Both file numbers and field numbers are 1 based, i.e. the first file on 87the command line is file number 1 and the first field is field number 1. 88The following options are available: 89.Bl -tag -width indent 90.It Fl a Ar file_number 91In addition to the default output, produce a line for each unpairable 92line in file 93.Ar file_number . 94.It Fl e Ar string 95Replace empty output fields with 96.Ar string . 97.It Fl o Ar list 98The 99.Fl o 100option specifies the fields that will be output from each file for 101each line with matching join fields. 102Each element of 103.Ar list 104has the either the form 105.Ql file_number.field , 106where 107.Ar file_number 108is a file number and 109.Ar field 110is a field number, or the form 111.Ql 0 112.Pq zero , 113representing the join field. 114The elements of list must be either comma 115.Pf ( Dq , Ns ) 116or whitespace separated. 117(The latter requires quoting to protect it from the shell, or, a simpler 118approach is to use multiple 119.Fl o 120options.) 121.It Fl t Ar char 122Use character 123.Ar char 124as a field delimiter for both input and output. 125Every occurrence of 126.Ar char 127in a line is significant. 128.It Fl v Ar file_number 129Do not display the default output, but display a line for each unpairable 130line in file 131.Ar file_number . 132The options 133.Fl v Ar 1 134and 135.Fl v Ar 2 136may be specified at the same time. 137.It Fl 1 Ar field 138Join on the 139.Ar field Ns 'th 140field of file 1. 141.It Fl 2 Ar field 142Join on the 143.Ar field Ns 'th 144field of file 2. 145.El 146.Pp 147When the default field delimiter characters are used, the files to be joined 148should be ordered in the collating sequence of 149.Xr sort 1 , 150using the 151.Fl b 152option, on the fields on which they are to be joined, otherwise 153.Nm 154may not report all field matches. 155When the field delimiter characters are specified by the 156.Fl t 157option, the collating sequence should be the same as 158.Xr sort 1 159without the 160.Fl b 161option. 162.Pp 163If one of the arguments 164.Ar file1 165or 166.Ar file2 167is 168.Dq - , 169the standard input is used. 170.Sh DIAGNOSTICS 171.Ex -std 172.Sh COMPATIBILITY 173For compatibility with historic versions of 174.Nm , 175the following options are available: 176.Bl -tag -width indent 177.It Fl a 178In addition to the default output, produce a line for each unpairable line 179in both file 1 and file 2. 180.It Fl j1 Ar field 181Join on the 182.Ar field Ns 'th 183field of file 1. 184.It Fl j2 Ar field 185Join on the 186.Ar field Ns 'th 187field of file 2. 188.It Fl j Ar field 189Join on the 190.Ar field Ns 'th 191field of both file 1 and file 2. 192.It Fl o Ar list ... 193Historical implementations of 194.Nm 195permitted multiple arguments to the 196.Fl o 197option. 198These arguments were of the form 199.Ql file_number.field_number 200as described 201for the current 202.Fl o 203option. 204This has obvious difficulties in the presence of files named 205.Ql 1.2 . 206.El 207.Pp 208These options are available only so historic shellscripts don't require 209modification and should not be used. 210.Sh STANDARDS 211The 212.Nm 213command conforms to 214.St -p1003.1-2001 . 215.Sh SEE ALSO 216.Xr awk 1 , 217.Xr comm 1 , 218.Xr paste 1 , 219.Xr sort 1 , 220.Xr uniq 1 221