>From: phk@flsco.fls.dk (Poul-Henning Kamp/P-HK)

[unix-history] / usr.bin / xargs / xargs.1

.\" Copyright (c) 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" John B. Roll Jr. and the Institute of Electrical and Electronics
.\" Engineers, Inc.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)xargs.1	5.5 (Berkeley) 6/27/91
.\"
.Dd June 27, 1991
.Dt XARGS 1
.Os
.Sh NAME
.Nm xargs
.Nd construct argument list(s) and execute utility.
.Sh SYNOPSIS
.Nm xargs 
.Op Fl t
.Oo
.Op Fl x
.Fl n Ar number
.Oc
.Op Fl s Ar size
.Oo
.Ar utility
.Op Ar argument Ar ...
.Oc
.Sh DESCRIPTION
The
.Nm xargs
utility reads space, tab, newline and end-of-file delimited arguments
from the standard input and executes the specified
.Ar utility
with them as arguments.
.Pp
The utility and any arguments specified on the command line are given
to the
.Ar utility
upon each invocation, followed by some number of the arguments read
from standard input.
The
.Ar utility
is repeatedly executed until standard input is exhausted.
.Pp
Spaces, tabs and newlines may be embedded in arguments using single 
or double quotes or backslashes.
Single quotes escape all non-single quote characters, excluding newlines,
up to the matching single quote.
Double quotes escape all non-double quote characters, excluding newlines,
up to the matching double quote.
Any single character, including newlines, may be escaped by a backslash.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl n Ar number
Set the maximum number of arguments taken from standard input for each
invocation of the utility.
An invocation of
.Ar utility
will use less than
.Ar number
standard input arguments if the number of bytes accumulated (see the
.Fl s
option) exceeds the specified
.Ar size
or there are fewer than
.Ar number
arguments remaining for the last invocation of
.Ar utility .
The current default value for
.Ar number
is 5000.
.It Fl s Ar size
Set the maximum number of bytes for the command line length provided to
.Ar utility .
The sum of the length of the utility name and the arguments passed to
.Ar utility
(including NULL terminators) will be less than or equal to this number.
The current default value for
.Ar size
is 
.Dv ARG_MAX 
- 2048.
.It Fl t
Echo the command to be executed to standard error immediately before it
is executed.
.It Fl x
Force
.Nm xargs
to terminate immediately if a command line containing
.Ar number
arguments will not fit in the specified (or default) command line length.
.El
.Pp
If no
.Ar utility
is specified,
.Xr echo 1
is used.
.Pp
Undefined behavior may occur if
.Ar utility
reads from the standard input.
.Sh DIAGNOSTICS
.Nm xargs
exits with one of the following values:
.Bl -tag -width Ds -compact
.It 0
All invocations of
.Ar utility
returned a zero exit status.
.It 123
One or more invocations of
.Ar utility
returned a nonzero exit status.
.It 124
The
.Ar utility
exited with a 255 exit status.
.It 125
The
.Ar utility
was killed or stopped by a signal.
.It 126
The
.Ar utility
was found but could not be invoked.
.It 127
The
.Ar utility
could not be found.
.It 1
Some other error occured.
.El
.Sh "SEE ALSO"
.Xr echo 1 ,
.Xr find 1
.Sh STANDARDS
.Nm xargs
is expected to be
.St -p1003.2
compliant.
.Sh HISTORY
The meaning of 123, 124, and 125 exit values were taken from GNU xargs.