NAME    [Toc]    [Back]

     getsubopt - get sub options from an argument

SYNOPSIS    [Toc]    [Back]

     #include <stdlib.h>

     extern char *suboptarg;

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

DESCRIPTION    [Toc]    [Back]

     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    [Toc]    [Back]

     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    [Toc]    [Back]

     getopt(3), strsep(3)

HISTORY    [Toc]    [Back]

     The getsubopt() function first appeared in 4.4BSD.

OpenBSD      3.6                           June      9,      1993