bsd man page for getsubopt

GETSUBOPT(3)						     Library Functions Manual						      GETSUBOPT(3)

NAME
       getsubopt - get sub options from an argument

SYNOPSIS
       #include <stdlib.h>

       extern char *suboptarg

       int
       getsubopt(optionp, tokens, valuep)
       char **optionp;
       char **tokens;
       char **valuep;

DESCRIPTION
       The  getsubopt()  function parses a string containing tokens delimited by one or more tab, space or comma (`,') characters.  It is intended
       for use in parsing groups of option arguments provided as part of a utility command line.

       The argument optionp is a pointer to a pointer to the string.  The argument tokens is a pointer to a NULL-terminated array of  pointers	to
       strings.

       The  getsubopt()  function  returns  the  zero-based offset of the pointer in the tokens array referencing a string which matches the first
       token in the string, or, -1 if the string contains no tokens or tokens does not contain a matching string.

       If the token is of the form ``name=value'', the location referenced by valuep will be set to point to the start of the ``value'' portion of
       the token.

       On return from getsubopt(), 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 suboptarg will be set to point to the start of the  current  token,  or  NULL  if	no
       tokens  were  present.  The argument valuep will be set to point to the ``value'' portion of the token, or NULL if no ``value'' portion was
       present.

EXAMPLE
       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;
	    }

SEE ALSO
       getopt(3), strsep(3)

HISTORY
       The getsubopt() function first appeared in 4.4BSD.

4.4 Berkeley Distribution					 January 12, 1996						      GETSUBOPT(3)