strlen

--- strlen.c ---
#include <stdio.h>
#include <string.h>

int main()
{
  char word2[256] = {'1', '2', '3', '4'};

  printf("word2 = %s, strlen(word2) = %d", word2, strlen(word2));
  return 0;
}
--- fordítás ---
gcc -Wall -ansi -pedantic -fno-builtin -g strlen.c
--- futtatás ---
word2 = 1234, strlen(word2) = 4
--- debug ---
gdb ./a.out

(start, next, next)

(gdb) print word2
$1 = "1234", '\000' <repeats 251 times>
(gdb) print strlen(word2)
$2 = 1742576