Question

the following code should call a command with excve for some reason i doesn’t print the contents of the current directory, but still the program returns "ok"

  1 #include <stdio.h>
  2 #include <unistd.h>
  3 int main ()
  4 { char *argv[]={"ls",NULL};·
  5   char *env[]={"PATH=/usr/local/sbin/:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games",NULL};
  6   if(execve("ls",argv,env))
  7   { printf("ok\n");
  8   }
  9   else
 10   { printf("not ok\n");
 11   }
 12   return 0;
 13 }      

Answer 1

Since execve does not return on success, it’s obvious that the call is failing somehow. It returns -1 on error, which would be treated as true (non-zero). That’s why it’s saying okay.

The most likely reason is that you haven’t specified the full path to the executable, which is a requirement for execve. Alternatively, if you want the path to be searched, use execvpe instead. See http://linux.die.net/man/3/exec for the gory details.