reverses a string

gistfile1.txt

#include <stdio.h>
#include <string.h>

int main ()
{
  char str0[]="Hello world";
  char str1[40];
  int str0_length = strlen(str0);
  int i;
  for( i = 1 ; i <= str0_length ; i++)
    str1[i - 1] = str0[ str0_length - i];
    
  printf ("%s\n",str1);
  return 0;
}