1.\" $NetBSD: xargs.1,v 1.14 2002/01/28 13:49:49 wiz 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 p 50.Op Fl t 51.Oo Op Fl x 52.Fl n Ar number 53.Oc 54.Op Fl s Ar size 55.Op Ar utility Op Ar arguments ... 56.Sh DESCRIPTION 57The 58.Nm 59utility reads space, tab, newline and end-of-file delimited arguments 60from the standard input and executes the specified 61.Ar utility 62with them as 63arguments. 64.Pp 65The utility and any arguments specified on the command line are given 66to the 67.Ar utility 68upon each invocation, followed by some number of the arguments read 69from standard input. 70The 71.Ar utility 72is repeatedly executed until standard input is exhausted. 73.Pp 74Spaces, tabs and newlines may be embedded in arguments using single 75(``\ '\ '') 76or double (``"'') quotes or backslashes (``\e''). 77Single quotes escape all non-single quote characters, excluding newlines, 78up to the matching single quote. 79Double quotes escape all non-double quote characters, excluding newlines, 80up to the matching double quote. 81Any single character, including newlines, may be escaped by a backslash. 82.Pp 83The options are as follows: 84.Bl -tag -width Fl 85.It Fl 0 86Use NUL 87(``\e0'') 88instead of whitespace as the argument separator. 89This can be used in conjuction with the 90.Fl print0 91option of 92.Xr find 1 . 93.It Fl n Ar number 94Set the maximum number of arguments taken from standard input for each 95invocation of the utility. 96An invocation of 97.Ar utility 98will use less than 99.Ar number 100standard input arguments if the number of bytes accumulated (see the 101.Fl s 102option) exceeds the specified 103.Ar size 104or there are fewer than 105.Ar number 106arguments remaining for the last invocation of 107.Ar utility . 108The current default value for 109.Ar number 110is 5000. 111.It Fl p 112Prompt mode: immediately before each command execution the user is prompted 113whether to execute the command instance. If an affirmative response is read 114from 115.Pa /dev/tty 116the command will be executed; otherwise this particular invocation will be 117skipped. 118This option implies the 119.Fl t 120option. 121.It Fl s Ar size 122Set the maximum number of bytes for the command line length provided to 123.Ar utility . 124The sum of the length of the utility name and the arguments passed to 125.Ar utility 126(including 127.Dv NULL 128terminators) will be less than or equal to this number. 129The current default value for 130.Ar size 131is 132.Dv ARG_MAX 133- 4096. 134.It Fl t 135Echo the command to be executed to standard error immediately before it 136is executed. 137.It Fl x 138Force 139.Nm 140to terminate immediately if a command line containing 141.Ar number 142arguments will not fit in the specified (or default) command line length. 143.El 144.Pp 145If no 146.Ar utility 147is specified, 148.Xr echo 1 149is used. 150.Pp 151Undefined behavior may occur if 152.Ar utility 153reads from the standard input. 154.Pp 155The 156.Nm 157utility exits immediately (without processing any further input) if a 158command line cannot be assembled, 159.Ar utility 160cannot be invoked, an invocation of the utility is terminated by a signal 161or an invocation of the utility exits with a value of 255. 162.Sh EXIT STATUS 163.Nm 164exits with one of the following values: 165.Bl -tag -width Ds -compact 166.It 0 167All invocations of 168.Ar utility 169returned a zero exit status. 170.It 123 171One or more invocations of 172.Ar utility 173returned a nonzero exit status. 174.It 124 175The 176.Ar utility 177exited with a 255 exit status. 178.It 125 179The 180.Ar utility 181was killed or stopped by a signal. 182.It 126 183The 184.Ar utility 185was found but could not be invoked. 186.It 127 187The 188.Ar utility 189could not be found. 190.It 1 191Some other error occurred. 192.El 193.Sh FILES 194.Bl -tag -width /dev/tty -compact 195.It Pa /dev/tty 196used to read responses in prompt mode 197.El 198.Sh SEE ALSO 199.Xr echo 1 , 200.Xr find 1 201.Sh STANDARDS 202The 203.Nm 204utility is expected to be 205.St -p1003.2 206compliant. 207.Sh HISTORY 208The 209.Nm xargs 210command appeared in PWB Unix 1.0. 211It made its first BSD appearance in the 4.3 Reno release. 212.Pp 213The meaning of 123, 124, and 125 exit values and the 214.Fl 0 215option were taken from GNU xargs. 216