Parsing a command line with getopt().

[mynameistmp]

bash-2.05b$ uname -osr ; gcc --version
Linux 2.4.22 GNU/Linux
gcc (GCC) 3.2.3

bash-2.05b$ make
gcc -Wall -ggdb  -c main.c
gcc main.o libs/isock.o libs/cmdline.c -o ircclient
bash-2.05b$ ./ircclient
Using default configuration file: bot.cfg...
$connect -s test
test

$connect -s test2
$connect test
Segmentation fault
bash-2.05b$

I'm trying to use getopt() to parse a commandline I created within the program. It works fine the first time through, but has problems the second time through. I'm not much of a programmer, so I've probably missed something fundamental. Any input is appreciated. If invocation code is necessary let me know, I tried to limit the length of the message. (For some reason phpbb screws up the indentation on the case in the switch statement.)

Code Select Expand


void com (char *buf, int buflen) {
 int b = 0;
 int option = 0;
 int argn = 0;
 char *args[16];
 char *p = strtok(buf, " ");
 for (; p; p = strtok(NULL, " "), argn++) {
   if (argn <= (sizeof(args)/4)) {
     args[argn] = p;
   } else {
     puts("Maximum of 17 parameters.");
     b = 1;
   }
 }

 if (!b && !strncmp(buf, "connect", 7)) {
  while ((option = getopt(argn, args, "s:")) != EOF) {
       switch (option) {
  case 's' :
    strcpy(server, optarg);
    puts(server);
    break;
  default:
    break;
  }
   }
 }  
}


[Adron]

I just read the getopt man page, and I don't see a way of telling it to restart the scan? Maybe that's the problem?

You could also try [ code ] tags, and see if those work any better than [ quote ].

[mynameistmp]

I fixed it by setting the external integer optind to 0 per iteration of the function, or 'restarting the scan'. Thanks for the insight =)

man 3 getopt:

If  there  are no more option characters, getopt() returns -1. Then optind is the index in argv of the  first  argv-element that is not an option.