[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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.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
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.\" 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
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.\" SUCH DAMAGE.
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.\"     @(#)getsubopt.3	8.1 (Berkeley) 6/9/93
.\" $FreeBSD: src/lib/libc/stdlib/getsubopt.3,v 1.9 2001/09/07 14:46:35 asmodai 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 unistd.h
.Vt extern char *suboptarg ;
.Ft int
.Fn getsubopt "char **optionp" "char * const *tokens" "char **valuep"
.Sh DESCRIPTION
The
.Fn getsubopt
function
parses a string containing tokens delimited by one or more tab, space or
comma
.Pq Ql \&,
characters.
It is intended for use in parsing groups of option arguments 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 tokens
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 tokens
array referencing a string which matches the first token
in the string, or, \-1 if the string contains no tokens or
.Fa tokens
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 *tokens[] = {
	#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, tokens, &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
5b2abdfb 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 1.9 2001/09/07 14:46:35 asmodai 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 unistd.h
	45	.Vt extern char *suboptarg ;
	46	.Ft int
	47	.Fn getsubopt "char *optionp" "char const tokens" "char *valuep"
	48	.Sh DESCRIPTION
	49	The
	50	.Fn getsubopt
	51	function
	52	parses a string containing tokens delimited by one or more tab, space or
	53	comma
	54	.Pq Ql \&,
	55	characters.
	56	It is intended for use in parsing groups of option arguments provided
	57	as part of a utility command line.
	58	.Pp
	59	The argument
	60	.Fa optionp
	61	is a pointer to a pointer to the string.
	62	The argument
	63	.Fa tokens
	64	is a pointer to a
65	.Dv NULL Ns -terminated
66	array of pointers to strings.
67	.Pp
68	The
69	.Fn getsubopt
70	function
71	returns the zero-based offset of the pointer in the
72	.Fa tokens
73	array referencing a string which matches the first token
74	in the string, or, \-1 if the string contains no tokens or
75	.Fa tokens
76	does not contain a matching string.
77	.Pp
78	If the token is of the form ``name=value'', the location referenced by
79	.Fa valuep
80	will be set to point to the start of the ``value'' portion of the token.
81	.Pp
82	On return from
83	.Fn getsubopt ,
84	.Fa optionp
85	will be set to point to the start of the next token in the string,
86	or the null at the end of the string if no more tokens are present.
87	The external variable
88	.Fa suboptarg
89	will be set to point to the start of the current token, or
90	.Dv NULL
91	if no
92	tokens were present.
93	The argument
94	.Fa valuep
95	will be set to point to the ``value'' portion of the token, or
96	.Dv NULL
97	if no ``value'' portion was present.
98	.Sh EXAMPLES
99	.Bd -literal -compact
100	char *tokens[] = {
101	#define ONE 0
102	"one",
103	#define TWO 1
104	"two",
105	NULL
106	};
107
108	\&...
109
110	extern char optarg, suboptarg;
111	char options, value;
112
113	while ((ch = getopt(argc, argv, "ab:")) != \-1) {
114	switch(ch) {
115	case 'a':
116	/* process ``a'' option */
117	break;
118	case 'b':
119	options = optarg;
120	while (*options) {
121	switch(getsubopt(&options, tokens, &value)) {
122	case ONE:
123	/* process ``one'' sub option */
124	break;
125	case TWO:
126	/* process ``two'' sub option */
127	if (!value)
128	error("no value for two");
129	i = atoi(value);
130	break;
131	case \-1:
132	if (suboptarg)
133	error("illegal sub option %s",
134	suboptarg);
135	else
136	error("missing sub option");
137	break;
138	}
139	break;
140	}
141	.Ed
142	.Sh SEE ALSO
143	.Xr getopt 3 ,
144	.Xr strsep 3
145	.Sh HISTORY
146	The
147	.Fn getsubopt
148	function first appeared in
149	.Bx 4.4 .