1.\" $NetBSD: xargs.1,v 1.12 2000/09/04 07:35:20 kleink Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" John B. Roll Jr. and the Institute of Electrical and Electronics 8.\" Engineers, Inc. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. All advertising materials mentioning features or use of this software 19.\" must display the following acknowledgement: 20.\" This product includes software developed by the University of 21.\" California, Berkeley and its contributors. 22.\" 4. Neither the name of the University nor the names of its contributors 23.\" may be used to endorse or promote products derived from this software 24.\" without specific prior written permission. 25.\" 26.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36.\" SUCH DAMAGE. 37.\" 38.\" @(#)xargs.1 8.1 (Berkeley) 6/6/93 39.\" 40.Dd December 21, 1999 41.Dt XARGS 1 42.Os 43.Sh NAME 44.Nm xargs 45.Nd "construct argument list(s) and execute utility" 46.Sh SYNOPSIS 47.Nm 48.Op Fl 0 49.Op Fl I Ar replstr 50.Op Fl p 51.Op Fl t 52.Oo Op Fl x 53.Fl n Ar number 54.Oc 55.Op Fl s Ar size 56.Op Ar utility Op Ar arguments ... 57.Sh DESCRIPTION 58The 59.Nm 60utility reads space, tab, newline and end-of-file delimited arguments 61from the standard input and executes the specified 62.Ar utility 63with them as 64arguments. 65.Pp 66The utility and any arguments specified on the command line are given 67to the 68.Ar utility 69upon each invocation, followed by some number of the arguments read 70from standard input. 71The 72.Ar utility 73is repeatedly executed until standard input is exhausted. 74.Pp 75Spaces, tabs and newlines may be embedded in arguments using single 76(``\ '\ '') 77or double (``"'') quotes or backslashes (``\e''). 78Single quotes escape all non-single quote characters, excluding newlines, 79up to the matching single quote. 80Double quotes escape all non-double quote characters, excluding newlines, 81up to the matching double quote. 82Any single character, including newlines, may be escaped by a backslash. 83.Pp 84The options are as follows: 85.Bl -tag -width Fl 86.It Fl 0 87Use NUL 88(``\e0'') 89instead of whitespace as the argument separator. 90This can be used in conjuction with the 91.Fl print0 92option of 93.Xr find 1 . 94.It Fl n Ar number 95Set the maximum number of arguments taken from standard input for each 96invocation of the utility. 97An invocation of 98.Ar utility 99will use less than 100.Ar number 101standard input arguments if the number of bytes accumulated (see the 102.Fl s 103option) exceeds the specified 104.Ar size 105or there are fewer than 106.Ar number 107arguments remaining for the last invocation of 108.Ar utility . 109The current default value for 110.Ar number 111is 5000. 112.It Fl p 113Prompt mode: immediately before each command execution the user is prompted 114whether to execute the command instance. If an affirmative response is read 115from 116.Pa /dev/tty 117the command will be executed; otherwise this particular invocation will be 118skipped. 119This option implies the 120.Fl t 121option. 122.It Fl s Ar size 123Set the maximum number of bytes for the command line length provided to 124.Ar utility . 125The sum of the length of the utility name and the arguments passed to 126.Ar utility 127(including 128.Dv NULL 129terminators) will be less than or equal to this number. 130The current default value for 131.Ar size 132is 133.Dv ARG_MAX 134- 4096. 135.It Fl t 136Echo the command to be executed to standard error immediately before it 137is executed. 138.It Fl x 139Force 140.Nm 141to terminate immediately if a command line containing 142.Ar number 143arguments will not fit in the specified (or default) command line length. 144.El 145.Pp 146If no 147.Ar utility 148is specified, 149.Xr echo 1 150is used. 151.Pp 152Undefined behavior may occur if 153.Ar utility 154reads from the standard input. 155.Pp 156The 157.Nm 158utility exits immediately (without processing any further input) if a 159command line cannot be assembled, 160.Ar utility 161cannot be invoked, an invocation of the utility is terminated by a signal 162or an invocation of the utility exits with a value of 255. 163.Sh FILES 164.Bl -tag -width /dev/tty -compact 165.It Pa /dev/tty 166used to read responses in prompt mode 167.El 168.Sh EXIT STATUS 169.Nm 170exits with one of the following values: 171.Bl -tag -width Ds -compact 172.It 0 173All invocations of 174.Ar utility 175returned a zero exit status. 176.It 123 177One or more invocations of 178.Ar utility 179returned a nonzero exit status. 180.It 124 181The 182.Ar utility 183exited with a 255 exit status. 184.It 125 185The 186.Ar utility 187was killed or stopped by a signal. 188.It 126 189The 190.Ar utility 191was found but could not be invoked. 192.It 127 193The 194.Ar utility 195could not be found. 196.It 1 197Some other error occurred. 198.El 199.Sh SEE ALSO 200.Xr echo 1 , 201.Xr find 1 202.Sh STANDARDS 203The 204.Nm 205utility is expected to be 206.St -p1003.2 207compliant. 208.Sh HISTORY 209The 210.Nm xargs 211command appeared in PWB Unix 1.0. 212It made its first BSD appearance in the 4.3 Reno release. 213.Pp 214The meaning of 123, 124, and 125 exit values and the 215.Fl 0 216option were taken from GNU xargs. 217