[apple/shell_cmds.git] / xargs / xargs.1

.\"	$NetBSD: xargs.1,v 1.7 1997/06/24 00:45:28 lukem Exp $
.\"
.\" Copyright (c) 1990, 1991, 1993
.\"	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	8.1 (Berkeley) 6/6/93
.\"
.Dd June 6, 1993
.Dt XARGS 1
.Os
.Sh NAME
.Nm xargs
.Nd "construct argument list(s) and execute utility"
.Sh SYNOPSIS
.Nm
.Op Fl 0
.Op Fl t
.Oo Op Fl x
.Fl n Ar number
.Oc
.Op Fl s Ar size
.Op Ar utility Op Ar arguments ...
.Sh DESCRIPTION
The
.Nm
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 (``\e'').
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 Fl
.It Fl 0
Use NUL
(``\e0'')
instead of whitespace as the argument separator.
This can be used in conjuction with the
.Fl print0
option of
.Xr find 1 .
.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
.Dv 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
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.
.Pp
The
.Nm
utility exits immediately (without processing any further input) if a
command line cannot be assembled,
.Ar utility
cannot be invoked, an invocation of the utility is terminated by a signal
or an invocation of the utility exits with a value of 255.
.Sh DIAGNOSTICS
.Nm
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 occurred.
.El
.Sh SEE ALSO
.Xr echo 1 ,
.Xr find 1
.Sh STANDARDS
The
.Nm
utility is expected to be
.St -p1003.2
compliant.
.Sh HISTORY
The meaning of 123, 124, and 125 exit values were taken from GNU xargs.
Commit	Line	Data
44bd5ea7 A	1	.\" $NetBSD: xargs.1,v 1.7 1997/06/24 00:45:28 lukem 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 June 6, 1993
	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 t
	50	.Oo Op Fl x
	51	.Fl n Ar number
	52	.Oc
	53	.Op Fl s Ar size
	54	.Op Ar utility Op Ar arguments ...
	55	.Sh DESCRIPTION
	56	The
	57	.Nm
	58	utility reads space, tab, newline and end-of-file delimited arguments
	59	from the standard input and executes the specified
	60	.Ar utility
	61	with them as
	62	arguments.
	63	.Pp
	64	The utility and any arguments specified on the command line are given
65	to the
66	.Ar utility
67	upon each invocation, followed by some number of the arguments read
68	from standard input.
69	The
70	.Ar utility
71	is repeatedly executed until standard input is exhausted.
72	.Pp
73	Spaces, tabs and newlines may be embedded in arguments using single
74	(``\ '\ '')
75	or double (``"'') quotes or backslashes (``\e'').
76	Single quotes escape all non-single quote characters, excluding newlines,
77	up to the matching single quote.
78	Double quotes escape all non-double quote characters, excluding newlines,
79	up to the matching double quote.
80	Any single character, including newlines, may be escaped by a backslash.
81	.Pp
82	The options are as follows:
83	.Bl -tag -width Fl
84	.It Fl 0
85	Use NUL
86	(``\e0'')
87	instead of whitespace as the argument separator.
88	This can be used in conjuction with the
89	.Fl print0
90	option of
91	.Xr find 1 .
92	.It Fl n Ar number
93	Set the maximum number of arguments taken from standard input for each
94	invocation of the utility.
95	An invocation of
96	.Ar utility
97	will use less than
98	.Ar number
99	standard input arguments if the number of bytes accumulated (see the
100	.Fl s
101	option) exceeds the specified
102	.Ar size
103	or there are fewer than
104	.Ar number
105	arguments remaining for the last invocation of
106	.Ar utility .
107	The current default value for
108	.Ar number
109	is 5000.
110	.It Fl s Ar size
111	Set the maximum number of bytes for the command line length provided to
112	.Ar utility .
113	The sum of the length of the utility name and the arguments passed to
114	.Ar utility
115	(including
116	.Dv NULL
117	terminators) will be less than or equal to this number.
118	The current default value for
119	.Ar size
120	is
121	.Dv ARG_MAX
122	- 2048.
123	.It Fl t
124	Echo the command to be executed to standard error immediately before it
125	is executed.
126	.It Fl x
127	Force
128	.Nm
129	to terminate immediately if a command line containing
130	.Ar number
131	arguments will not fit in the specified (or default) command line length.
132	.El
133	.Pp
134	If no
135	.Ar utility
136	is specified,
137	.Xr echo 1
138	is used.
139	.Pp
140	Undefined behavior may occur if
141	.Ar utility
142	reads from the standard input.
143	.Pp
144	The
145	.Nm
146	utility exits immediately (without processing any further input) if a
147	command line cannot be assembled,
148	.Ar utility
149	cannot be invoked, an invocation of the utility is terminated by a signal
150	or an invocation of the utility exits with a value of 255.
151	.Sh DIAGNOSTICS
152	.Nm
153	exits with one of the following values:
154	.Bl -tag -width Ds -compact
155	.It 0
156	All invocations of
157	.Ar utility
158	returned a zero exit status.
159	.It 123
160	One or more invocations of
161	.Ar utility
162	returned a nonzero exit status.
163	.It 124
164	The
165	.Ar utility
166	exited with a 255 exit status.
167	.It 125
168	The
169	.Ar utility
170	was killed or stopped by a signal.
171	.It 126
172	The
173	.Ar utility
174	was found but could not be invoked.
175	.It 127
176	The
177	.Ar utility
178	could not be found.
179	.It 1
180	Some other error occurred.
181	.El
182	.Sh SEE ALSO
183	.Xr echo 1 ,
184	.Xr find 1
185	.Sh STANDARDS
186	The
187	.Nm
188	utility is expected to be
189	.St -p1003.2
190	compliant.
191	.Sh HISTORY
192	The meaning of 123, 124, and 125 exit values were taken from GNU xargs.