Thread: Converting string to unsigned long

I'm passing a memory address as arguments to a program but when I try and convert the string to an unsigned long, I don't get anything.

Code:

int main(int argc,char *argv[])
{
   unsigned long address = strtoul(argv[1])
   printf("Address: %ul\n",address);
}

It just prints out a 0. The address I tried passing was bfffffff.

Can I not pass hex values as arguments?

First of all, strtoul() takes 3 arguments. Secondly, the format specifier for unsigned long is %lu, not %ul. Try this:

Code:

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
   unsigned long address = strtoul(argv[1], NULL, 0);
   printf("Address: %lu\n",address);
   return EXIT_SUCCESS;
}

If the value you are passing is hex, pass it as "0xbfffffff", or change the last parameter to strtoul() to 16 (then you can leave off the preceding 0x).

thanks, that helped!