REVERSE_of_STRING...

I keep getting segfaults when trying to run the code below. It seems Runtime error due to the line the *end = *begin; . Why is that?


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

void my_strrev(char* begin)
{
char temp;
char* end;
end = begin + strlen(begin)-1;

while(end>begin){
temp = *end;
*end = *begin;
*begin = temp;
end--;
begin++;
}
}

main()
{
char *string = "school";
my_strrev(string);
printf("%s", string);
}

For your purposes, this is wrong:

Code:

---

char *string = "school";

---

It should be:

Code:

---

char string[] = "school";

---

Otherwise you have a pointer to the first element of a string literal, and you cannot modify that string literal.

By the way, please post code in [code][/code] bbcode tags.

Quote:

---

Originally Posted by Tanushreeagr

I keep getting segfaults

---

What program written in Visual C++ segfaults?

Oh, you mean you're running this in Linux or some other OS and not using Visual C++? Then why did you post in the Visual C++ forum? Next time, post such questions in the Non Visual C++ forum.

If you did compile with Visual C++, the result should have been an unhandled exception (access violation). The reasons being the same as laserlight stated -- it is undefined behaviour to modify a string literal.

Regards,

Paul McKenzie