I've tried reinventing the strcpy C function, but when I try to run it I get this error:
Unhandled exception at 0x00411506 in brainf%ck.exe: 0xC0000005: Access violation writing location 0x00415760.
The error occurs in the *dest = *src; line. Here's the code:
char* strcpy(char* dest, const char* src) {
char* dest2 = dest;
while (*src) {
*dest = *src;
src++;
dest++;
}
*dest = '\0';
return dest2;
}
EDIT: Wow, that was fast. Here's the calling code (strcpy is defined in mystring.c):
#include "mystring.h"
#include <stdio.h>
int main() {
char* s = "hello";
char* t = "abc";
printf("%s", strcpy(s, t));
getchar();
return 0;
}
Answer
char* s = "hello";
char* t = "abc";
printf("%s", strcpy(s, t));
The compiler placed your destination buffer, s, in read-only memory since it is a constant.
char s[5];
char* t = "abc";
printf("%s", strcpy(s, t));
Should fix this problem. This allocates the destination array on the stack, which is writable.