source: trunk/libs/newlib/src/newlib/libc/stdlib/getsubopt.3 @ 471

Last change on this file since 471 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
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1.\" Copyright (c) 1990, 1991, 1993
2.\"     The Regents of the University of California.  All rights reserved.
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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
49The
50.Fn getsubopt
51function
52parses a string containing tokens delimited by one or more tab, space or
53comma
54.Pq Ql \&,
55characters.
56It is intended for use in parsing groups of option arguments provided
57as part of a utility command line.
58.Pp
59The argument
60.Fa optionp
61is a pointer to a pointer to the string.
62The argument
63.Fa tokens
64is a pointer to a
65.Dv NULL Ns -terminated
66array of pointers to strings.
67.Pp
68The
69.Fn getsubopt
70function
71returns the zero-based offset of the pointer in the
72.Fa tokens
73array referencing a string which matches the first token
74in the string, or, \-1 if the string contains no tokens or
75.Fa tokens
76does not contain a matching string.
77.Pp
78If the token is of the form ``name=value'', the location referenced by
79.Fa valuep
80will be set to point to the start of the ``value'' portion of the token.
81.Pp
82On return from
83.Fn getsubopt ,
84.Fa optionp
85will be set to point to the start of the next token in the string,
86or the null at the end of the string if no more tokens are present.
87The external variable
88.Fa suboptarg
89will be set to point to the start of the current token, or
90.Dv NULL
91if no
92tokens were present.
93The argument
94.Fa valuep
95will be set to point to the ``value'' portion of the token, or
96.Dv NULL
97if no ``value'' portion was present.
98.Sh EXAMPLES
99.Bd -literal -compact
100char *tokens[] = {
101        #define ONE     0
102                "one",
103        #define TWO     1
104                "two",
105        NULL
106};
107
108\&...
109
110extern char *optarg, *suboptarg;
111char *options, *value;
112
113while ((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
146The
147.Fn getsubopt
148function first appeared in
149.Bx 4.4 .
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