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 28  .\"     @(#)getsubopt.3	8.1 (Berkeley) 6/9/93
 29  .\" $FreeBSD: src/lib/libc/stdlib/getsubopt.3,v 1.11 2007/01/09 00:28:10 imp Exp $
 30  .\"
 31  .Dd June 9, 1993
 32  .Dt GETSUBOPT 3
 33  .Os
 34  .Sh NAME
 35  .Nm getsubopt
 36  .Nd get sub options from an argument
 37  .Sh LIBRARY
 38  .Lb libc
 39  .Sh SYNOPSIS
 40  .In stdlib.h
 41  .Vt extern char *suboptarg ;
 42  .Ft int
 43  .Fo getsubopt
 44  .Fa "char **optionp"
 45  .Fa "char *const *keylistp"
 46  .Fa "char **valuep"
 47  .Fc
 48  .Sh DESCRIPTION
 49  The
 50  .Fn getsubopt
 51  function
 52  parses a string containing tokens that are delimited
 53  by one or more tab, space, or comma
 54  .Pq Ql \&,
 55  characters.
 56  It is intended for use in parsing groups of option arguments
 57  that are provided 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 keylistp
 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 keylistp
 73  array, referencing a string which matches the first token in the string
 74   or \-1 if the string contains no tokens or
 75  .Fa keylistp
 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 *keylistp[] = {
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, keylistp, &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 .