Question

I have a program that needs to be called using:

program parameter1 parameter2 -x1 -y

but I feel that it should work if I do:

program -x1 -y parameter1 parameter2

or combinations thereof. How do I get parameter1 and parameter2 without a horrid dirty hack? At the moment I have a

while ((c = getopt (argc, argv, "x:y")) != -1){
   /* do stuff */
}

loop for the optional arguments, but what about the others? It would seem wrong to just look at argv[1] and argv[2] because they could be anywhere.

I’m sure there is an established solution to this.

Answer 1

After you exit the while loop, optind points to the first non-option argument. Take a look at the getopt(3) man page:

   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.

So your first non-option argument is argv[optind] and so forth.

while ((c = getopt (argc, argv, "x:y")) != -1){
   /* do stuff */
} 

param1 = argv[optind]
param2 = argv[optind+1]

getopt will permute the arguments so that this will still be true even for your first example, where the option arguments are on the command line after the non-option arguments.