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GETSUBOPT(3)		     Library Functions Manual		    GETSUBOPT(3)

NAME
     getsubopt -- get sub options from an argument

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <stdlib.h>

     extern char *suboptarg;

     int
     getsubopt(char **optionp, char * const *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.

EXAMPLES
     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.

FreeBSD ports 15.1		December 25, 2011		    GETSUBOPT(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=getsubopt&manpath=FreeBSD+15.1-RELEASE+and+Ports>

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