Thread: strings Vs. Char pointers

Hello,
I wanna illustrate the difference between a char array (a string that is) and a pointer to char using a simple function which say capitalizes all the letters of a given string.

To that affect I have written a simple code which (hopefully) should be doing just that. I have a function which does the checkin g and the capitalizing part. The function accepts a char pointer as an argument so I pass it a char pointer once and a char array the other time.

So I hope that the former one should give me a seg fault as i am trying to access and write back to a memory element which does not belong to the function (is it a scope issue or what??...im bedazled as of now). And yeah it does flag a seg fault for the former case.

However when I pass the array (using the name of the array which is also a char pointer) it still flags the seg fault error!!!..why is that..

heres the code:

Code:

#include <stdio.h>
#include <ctype.h>

void set2caps(char *);//func prototype for capitalizing letters of string

int main()

{
    char *str = "string for pointer";
 //   char str1[] = "string for array";

    set2caps(str);
    set2caps(str1);

    puts("strings displayed in caps\n");

  //  printf("str in caps is &#37;s\n",str);
    printf("str1 in caps is %s\n",str);

    return 0;
}

void set2caps(char *str_hld)

{
    unsigned int chr_cnt = 0;
    char temp;

    while(str_hld[chr_cnt]) {
        if (!isupper(str_hld[chr_cnt]))
            temp = toupper(str_hld[chr_cnt]);
        str_hld[chr_cnt] = temp;
        chr_cnt++;
    }
}