Question

I’m not very good at C, and I always get stuck on simple string manipulation tasks (that’s why I love Perl!).

I have a string that contains a file path like ‘/Volumes/Media/Music/Arcade Fire/Black Mirror.aac’. I need to extract the drive name (‘Media’ or preferably ‘/Volumes/Media’) from that path.

Any help would be greatly appreciated, just as I try to return the favor on the Perl questions!

• Jim

Answer 1

I think sscanf could be appropriate:

#include <stdlib.h> #include <string.h> #include <stdio.h>  void test(char const* path) {     int len;     if(sscanf(path, '/Volumes/%*[^/]%n', &len) != EOF) {         char *drive = malloc(len + 1);         strncpy(drive, path, len);         drive[len] = '\0';          printf('drive is %s\n', drive);         free(drive);     } else {         printf('match failure\n');     } }  int main() {     test('/Volumes/Media/Foo');     test('/Volumes/Media');     test('/Volumes'); } 

Output:

drive is /Volumes/Media drive is /Volumes/Media match failure