2.11BSD#431 - /usr/man/cat3/getsubopt.0

GETSUBOPT(3)	    UNIX Programmer's 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 (`,') charac-
     ters.  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'' por-
     tion was present.

EXAMPLE
     char *tokens[] = {
	  #define   ONE  0
	       "one",
	  #define   TWO  1
	       "two",
	  NULL
     };


Printed 11/26/99	January 12, 1996			1


GETSUBOPT(3)	    UNIX Programmer's Manual	     GETSUBOPT(3)


     ...

     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.


Printed 11/26/99	January 12, 1996			2