Passing few arguments via getopt - c

Question

What I want to do is to get more arguments from the command line and get them output each one on a new line. How could I do that by keeping the same structure? I want also to get the -f output.
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
int
main(int argc, char *argv[])
{
int nod1, opt;
int nsecs, nod2;
nsecs = 0;
nod2 = 0;
nod1 = 0;
while ((opt = getopt(argc, argv, "nf:")) != -1) {
switch (opt) {
case 'n':
nod1 = 1;
break;
case 'f':
nsecs = atoi(optarg);
nod2 = 1;
break;
default: /* '?' */
fprintf(stderr, "Usage: %s [-t nsecs] [-n] name\n",
argv[0]);
exit(EXIT_FAILURE);
}
}
printf("nod1=%d; nod2=%d; optind=%d\n", nod1, nod2, optind);
if (optind >= argc) {
fprintf(stderr, "Expected argument after options\n");
exit(EXIT_FAILURE);
}
printf("Output = %s\n", argv[optind]);
/* Other code omitted */
exit(EXIT_SUCCESS);
}
From a comment:
The arguments after the -f should be optional and I want to list every single one that has been passed under one another...
$ ./partitioner -n 4 -f Test1 Test2 Test3 Test4
Number:4
File names:
Output = Test1
Output = Test2
Output = Test3
Output = Test4
$

Answer 1

Having in account the comment made by Jonathan Leffler I edit my answer:
POSIX getopt() doesn't really handle optional arguments sensibly. GNU getopt() is a bit better, but not by much. Avoid them whenever you can.
I come out with a simple idea, but one that could solve your problem so here it is:
In argv you have a list of arguments ordered as they was in the commend line right? So, if you can find any -f in argv that means all arguments following -f until another option or the end of the argument list are the options you want to print.
From -f to another option(-g in this case):
./command -a A -b B -f one two tree -g G
From -f to the end.
./command -a A -b B -f one two tree
Here you have a helper function for doing that:
bool get_f_args(int argc, char *argv[], int &count, int* indexes)
{
bool f_found = false, parsing_f_args = false;
int collect_count = 0;
if (argc < 3) return false; // "./command -f" are just two values for argv
// we need at least 3.
// Check for every argument in the argument list.
for (int i = 1; i < argc; i++)
{
// If you found another option
// stop collecting args.
if (argv[i][0] == '-' && parsing_f_args) // options starts with '-' character.
parsing_f_args = false;
if (parsing_f_args)
indexes[count++] = i;
// If some is "-f" then the following are the
// ones you're looking for. We check for -f after
//
// indexes[count++] = i;
//
// in roder to avoid adding -f index to indexes.
if (strcmp("-f", argv[i]) == 0) {
parsing_f_args = true;
f_found = true;
}
}
return f_found;
}
And here is an example of use:
int main(int argc, char* argv[])
{
int count = 0;
int indexes[10];
bool f_found = get_f_args(argc, argv, count, indexes);
if (f_found){
for (int i = 0; i < count; i++)
printf("Ouput = %s\n", argv[indexes[i]]);
}
return 0;
}