array size

#include <stdio.h>

/*
 * $ gcc -Wall size.c -o size.o
 * $ nm -S size.o |grep -w D
 * 0000000000000000 0000000000000007 D s1
 * 0000000000000007 0000000000000006 D s2
 * 000000000000000d 0000000000000006 D s3
 * $ ./size
 * s1      7
 * s2      6
 * s3      6
 */

char s1[] = "123456";
char s2[6] = "123456";
char s3[] = {'1', '2', '3', '4', '5', '6'};

int main(int argc, char *argv[])
{

    printf("s1  %lu\n", sizeof(s1));
    printf("s2  %lu\n", sizeof(s2));
    printf("s3  %lu\n", sizeof(s3));

    return 0;
}