getopt()

[threahdead]

i have problems using the getopt().

...

char lala, test[2];

while((lala = getopt(argc, argv, "m:S:")) != EOF)
{
   switch(lala)
   {
      case 'm':
      {
          printf("%s\n", optarg);
          ....
          break;
      }

      case 'S':
      {
          printf("%s\n", optarg);
          sscanf(optarg, "%x:%x", test[0], test[1]);
          break;
      }
      
     default: break;
    }
}

when i use printf() to print the optarg of case S, it tells me that it is (null).
so i get a segmentation violation.
why is optarg (null)?

thanks

[threahdead]

Originally posted by vVv
getopt( ) returns int, not char.

so what i am supposed to change?

lets assume i run the code like that:

./program -m printit -S ff:ff
output:

printit
SIGSEGV

as it seems there is no problem with printing the string "printit" for case 'm'.
but why is optarg = null in case S only?

thanks