[apple/libc.git] / stdlib / getsubopt.3

.\" Copyright (c) 1990, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
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.\"    notice, this list of conditions and the following disclaimer in the
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.\"    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)
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.\"     @(#)getsubopt.3	8.1 (Berkeley) 6/9/93
.\" $FreeBSD: src/lib/libc/stdlib/getsubopt.3,v 1.10 2004/02/23 03:32:10 ache Exp $
.\"
.Dd June 9, 1993
.Dt GETSUBOPT 3
.Os
.Sh NAME
.Nm getsubopt
.Nd get sub options from an argument
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Vt extern char *suboptarg ;
.Ft int
.Fo getsubopt
.Fa "char **optionp"
.Fa "char *const *keylistp"
.Fa "char **valuep"
.Fc
.Sh DESCRIPTION
The
.Fn getsubopt
function
parses a string containing tokens that are delimited
by one or more tab, space, or comma
.Pq Ql \&,
characters.
It is intended for use in parsing groups of option arguments
that are provided as part of a utility command line.
.Pp
The argument
.Fa optionp
is a pointer to a pointer to the string.
The argument
.Fa keylistp
is a pointer to a
.Dv NULL Ns -terminated
array of pointers to strings.
.Pp
The
.Fn getsubopt
function
returns the zero-based offset of the pointer in the
.Fa keylistp
array, referencing a string which matches the first token in the string
 or \-1 if the string contains no tokens or
.Fa keylistp
does not contain a matching string.
.Pp
If the token is of the form ``name=value'', the location referenced by
.Fa valuep
will be set to point to the start of the ``value'' portion of the token.
.Pp
On return from
.Fn getsubopt ,
.Fa optionp
will be set to point to the start of the next token in the string,
or the null at the end of the string if no more tokens are present.
The external variable
.Fa suboptarg
will be set to point to the start of the current token, or
.Dv NULL
if no
tokens were present.
The argument
.Fa valuep
will be set to point to the ``value'' portion of the token, or
.Dv NULL
if no ``value'' portion was present.
.Sh EXAMPLES
.Bd -literal -compact
char *keylistp[] = {
	#define	ONE	0
		"one",
	#define	TWO	1
		"two",
	NULL
};

\&...

extern char *optarg, *suboptarg;
char *options, *value;

while ((ch = getopt(argc, argv, "ab:")) != \-1) {
	switch(ch) {
	case 'a':
		/* process ``a'' option */
		break;
	case 'b':
		options = optarg;
		while (*options) {
			switch(getsubopt(&options, keylistp, &value)) {
			case ONE:
				/* process ``one'' sub option */
				break;
			case TWO:
				/* process ``two'' sub option */
				if (!value)
					error("no value for two");
				i = atoi(value);
				break;
			case \-1:
				if (suboptarg)
					error("illegal sub option %s",
					  suboptarg);
				else
					error("missing sub option");
				break;
		}
		break;
	}
.Ed
.Sh SEE ALSO
.Xr getopt 3 ,
.Xr strsep 3
.Sh HISTORY
The
.Fn getsubopt
function first appeared in
.Bx 4.4 .
Commit	Line	Data
224c7076 A	1	.\" Copyright (c) 1990, 1991, 1993
	2	.\" The Regents of the University of California. All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 3. All advertising materials mentioning features or use of this software
	13	.\" must display the following acknowledgement:
	14	.\" This product includes software developed by the University of
	15	.\" California, Berkeley and its contributors.
	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
	32	.\" @(#)getsubopt.3 8.1 (Berkeley) 6/9/93
	33	.\" $FreeBSD: src/lib/libc/stdlib/getsubopt.3,v 1.10 2004/02/23 03:32:10 ache Exp $
	34	.\"
	35	.Dd June 9, 1993
	36	.Dt GETSUBOPT 3
	37	.Os
	38	.Sh NAME
	39	.Nm getsubopt
	40	.Nd get sub options from an argument
	41	.Sh LIBRARY
	42	.Lb libc
	43	.Sh SYNOPSIS
	44	.In stdlib.h
	45	.Vt extern char *suboptarg ;
	46	.Ft int
	47	.Fo getsubopt
	48	.Fa "char **optionp"
	49	.Fa "char const keylistp"
	50	.Fa "char **valuep"
	51	.Fc
	52	.Sh DESCRIPTION
	53	The
	54	.Fn getsubopt
	55	function
	56	parses a string containing tokens that are delimited
	57	by one or more tab, space, or comma
	58	.Pq Ql \&,
	59	characters.
	60	It is intended for use in parsing groups of option arguments
	61	that are provided as part of a utility command line.
	62	.Pp
	63	The argument
	64	.Fa optionp
65	is a pointer to a pointer to the string.
66	The argument
67	.Fa keylistp
68	is a pointer to a
69	.Dv NULL Ns -terminated
70	array of pointers to strings.
71	.Pp
72	The
73	.Fn getsubopt
74	function
75	returns the zero-based offset of the pointer in the
76	.Fa keylistp
77	array, referencing a string which matches the first token in the string
78	or \-1 if the string contains no tokens or
79	.Fa keylistp
80	does not contain a matching string.
81	.Pp
82	If the token is of the form ``name=value'', the location referenced by
83	.Fa valuep
84	will be set to point to the start of the ``value'' portion of the token.
85	.Pp
86	On return from
87	.Fn getsubopt ,
88	.Fa optionp
89	will be set to point to the start of the next token in the string,
90	or the null at the end of the string if no more tokens are present.
91	The external variable
92	.Fa suboptarg
93	will be set to point to the start of the current token, or
94	.Dv NULL
95	if no
96	tokens were present.
97	The argument
98	.Fa valuep
99	will be set to point to the ``value'' portion of the token, or
100	.Dv NULL
101	if no ``value'' portion was present.
102	.Sh EXAMPLES
103	.Bd -literal -compact
104	char *keylistp[] = {
105	#define ONE 0
106	"one",
107	#define TWO 1
108	"two",
109	NULL
110	};
111
112	\&...
113
114	extern char optarg, suboptarg;
115	char options, value;
116
117	while ((ch = getopt(argc, argv, "ab:")) != \-1) {
118	switch(ch) {
119	case 'a':
120	/* process ``a'' option */
121	break;
122	case 'b':
123	options = optarg;
124	while (*options) {
125	switch(getsubopt(&options, keylistp, &value)) {
126	case ONE:
127	/* process ``one'' sub option */
128	break;
129	case TWO:
130	/* process ``two'' sub option */
131	if (!value)
132	error("no value for two");
133	i = atoi(value);
134	break;
135	case \-1:
136	if (suboptarg)
137	error("illegal sub option %s",
138	suboptarg);
139	else
140	error("missing sub option");
141	break;
142	}
143	break;
144	}
145	.Ed
146	.Sh SEE ALSO
147	.Xr getopt 3 ,
148	.Xr strsep 3
149	.Sh HISTORY
150	The
151	.Fn getsubopt
152	function first appeared in
153	.Bx 4.4 .