stdlib/FreeBSD/getsubopt.3

   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 .