Command-line options in C

Question

I would like to create a C program that accepts an argument of the form

-aK

where K is some integer from 0-9.

How would I parse/specify this option?

Use `getopt` ? Or `bsd-getopt_long` ? – Paul R Jan 14 '13 at 22:11 — Paul R, Jan 14 '13 at 22:11
After using `getopt`, Try to accept more than 18% ;-) – masoud Jan 14 '13 at 22:17 — masoud, Jan 14 '13 at 22:17

score 6 · Accepted Answer · edited Jan 14 '13 at 22:19

6

You might want to check out getopt and/or getopt_long.

edited Jan 14 '13 at 22:19

answered Jan 14 '13 at 22:12

jgr

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Aniket Inge · Answer 2 · 2013-01-14T22:28:21.913

0

a simple requirement like this can be solved with getopt.

Also you can do this:

 #include <stdio.h>
 #include <string.h>
 int main(int argc, char *argv[])
 {
    char ch, a;
    int d;
    if(argc == 1) return;
    if(argc == 2){
       if(strlen(argv[1]) > 2){
       sscanf(argv[1],"%c%c%d",&ch,&a,&d);
       if(ch == '-' && a == 'a'){
          printf("%d is your number",d);
      }
    }
   }
   return 0;
 }

edited Jan 14 '13 at 22:28

answered Jan 14 '13 at 22:15

Aniket Inge

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@VladLazarenko at least Aniket gave an answer, as opposed to you, who just edits and votes – hd1 Jan 14 '13 at 22:21
1

I'm not the downvoter, But It did not any bound-checking or parse-checking. This program is potentially crash-able. – masoud Jan 14 '13 at 22:22
@VladLazarenko explain why its terrible? – Aniket Inge Jan 14 '13 at 22:22
@MasoudM. obviously it was a proof of concept, not production quality. I would certainly use getopt and do all kinds of bounds checking – Aniket Inge Jan 14 '13 at 22:23
@Aniket Well you just gave yourself a hint why it's a terrible example `bound checking` – Theocharis K. Jan 14 '13 at 22:23

Command-line options in C

2 Answers2