[tedman]

main() {

char *s = "IDIOT";
char *start, *end;
start = s;
end = s+strlen(s)-1;
printf("%c, %c",*start, *end);      // prints   I   T
*start = *end;                            // crashing at this point
printf("%c, %c",*start, *end);     // should print T   T

}

What I'm trying to do above is just replace I with T and I'm getting a segmentation fault!!! am clueless, please can someone help!!!

[DaWei]

In many modern OSs a string generated such as you have generated it lies in protected memory space. That means you can read it, but not write it. You can put it in local, writable space, if you like:

char writableString [] = "IDIOT";
char *start = writableString;
...etc., etc.

[shabbir]

DaWei, good answer. Probably thats the main reason some modern languages like C# and java have 2 types of string the editable and the one that is not editable. I always wondered why they have such things and the main reason might lie in this thread.