Use sample program from called getopt. c (provided below)
Make a copy of getopt. c and call it gactivity. c
Create a Makefile to compile the activity program.
Modify gactivity. c for the following usage:
Usage: gactivity [-b] -c cname -d data value1 value2 [value ...]
Where the -b option is optional
The -c option is required and needs an argument to go with it.
The -d option is required and needs an argument to go with it.
At least two value are included but there may be more than two.
The program should print out all the flags and values at the end so it should be modified throughout to match the new usage.
Program should print error if invalid options are used or missing options or parameters.
getopt. c

/*
example of command line parsing via getopt
usage: getopt [-dmp] -f fname [-s sname] name [name ...]

Paul Krzyzanowski
*/

#include
#include

int debug = 0;

int
main(int argc, char **argv)
{
extern char *optarg;
extern int optind;
int c, err = 0;
int mflag=0, pflag=0, fflag = 0, sflag=0;
char *sname = "default_sname", *fname;
static char usage[] = "usage: %s [-dmp] -f fname [-s sname] name [name ...]\n";

while ((c = getopt(argc, argv, "df:mps:")) != -1)
switch (c) {
case 'd':
debug = 1;
break;
case 'm':
mflag = 1;
break;
case 'p':
pflag = 1;
break;
case 'f':
fflag = 1;
fname = optarg;
break;
case 's':
sflag = 1;
sname = optarg;
break;
case '?':
err = 1;
break;
}
if (fflag == 0) { /* -f was mandatory */
fprintf(stderr, "%s: missing -f option\n", argv[0]);
fprintf(stderr, usage, argv[0]);
exit(1);
} else if ((optind+1) > argc) {
/* need at least one argument (change +1 to +2 for two, etc. as needeed) */

printf("optind = %d, argc=%d\n", optind, argc);
fprintf(stderr, "%s: missing name\n", argv[0]);
fprintf(stderr, usage, argv[0]);
exit(1);
} else if (err) {
fprintf(stderr, usage, argv[0]);
exit(1);
}
/* see what we have */
printf("debug = %d\n", debug);
printf("pflag = %d\n", pflag);
printf("mflag = %d\n", mflag);
printf("fname = \"%s\"\n", fname);
printf("sname = \"%s\"\n", sname);

if (optind < argc) /* these are the arguments after the command-line options */
for (; optind < argc; optind++)
printf("argument: \"%s\"\n", argv[optind]);
else {
printf("no arguments left to process\n");
}
exit(0);
}