GETOPT() EXAMPLE
			----------------
Reference
---------

	solaris> man -s 3c getopt

Usage Examples
--------------

	foo -S SearchFile -L LogFile -N 1

Global Area
-----------
/* define 3 switches: -S, -L, -N.  The ":" says that there are */
/* values following the switches  */
static char *options = "S:L:N:";

A function to process command line arguments
--------------------------------------------

void
parseargs(int argc, char *argv[]) {
...
    int		c;
    int		ok = 1;
 
    /* default parameter values */
    ...

    /* processing loop */
    while ((c = getopt(argc, argv, options)) != -1) {
	switch (c) {
	case 'S':
	    sfname = strdup (optarg);
	    break;
	case 'L':
	    lfname = strdup (optarg);
	    break;
	case 'N':
	    N = atoi(optarg);
	    ...
	    break;
	default:
	    ok = 0;
	}
    }
 
    if (!ok || optind < argc) {
	fprintf (stderr, "Usage: foo [-S SearchFile] [-N N]");
	exit(1);
	}

    /* display parameter values */
    ...

    }

parseargs usage
---------------

main(int argc, char *argv[]) {

    ...
    parseargs (argc, argv);			/* get parameters */
    ...

    }

Equivalent C Code
-----------------

The equivalent code using just 'argc' and 'argv' is something like:

    int		nargs, i, N;
    char	c;
    char	sfname[MAXNAME], lfname[MAXNAME];
    nargs = argc - 1;
    i = 0;
    while (i < nargs) {
	c = *(argv[i]);		/* get 1st char of next arg */
	switch (c) {
	case '-':
	    if (i < (nargs-1)) {	/* need another arg after the flag */
		if (strcmp(argv[i], "-S") {
		    sfname = strdup(argv[i+1]);
		    break;
		} else if (strcmp(argv[i], "-L") {
		    lfname = strdup(argv[i+1]);
		    break;
		} else if (strcmp(argv[i], "-N") {
	    	    N = atoi(argv[i+1]);
		    break;
		} else {
		    ... ERROR: Bad flag ...
		}
		i++;
	    } else	... ERROR: missing arg ...
	default:
	    ... ERROR ...
	}
    }