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GETSUBOPT(3)             BSD 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 *keylistp, char **valuep);

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

     The argument optionp is a pointer to a pointer to the string.  The argument keylistp 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 keylistp array, referenc-ing referencing
     ing a string which matches the first token in the string
      or -1 if the string contains no tokens or keylistp 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 argu-ment argument
     ment valuep will be set to point to the ``value'' portion of the token, or NULL if no ``value'' portion
     was present.

EXAMPLES
     char *keylistp[] = {
             #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, keylistp, &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.

BSD                              June 9, 1993                              BSD