I want to do something simple but I've been banging my head on this for too long. I have a string that will always end with a specific "token". In the case below "++". I want to replace the ending token with a shorter token, let's say "#".
strstr returns either NULL or a pointer to the initial ending token.
strcpy should take the pointer returned from strstr and overwrite the "++" with "#\0".
At least that's what I think it should do. Instead, I get an "assignment makes integer from pointer without a cast" warning. I have tried strcpy(*newThing, "#"); and a few other things at this point. the things that don't give errors cause seg-faults.
Is it that in this case C is taking the storage for the original string from some immutable space on the stack? Do I need to use one of the "alloc"s? I've tried that too but might have missed something.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main() {
char *thing="ssssssssssssssss++";
char *newThing;
newThing = strstr(thing, "++");
strcpy(newThing, "#");
printf("%s\n", thing);
exit(0);
}
Your problem is that thing is a pointer that points to a string literal. In the old days, you could have done that, but current compilers stores string literal in non writeable memory.
So when you execute you code you get a Access violation writing location (or equivalent message).
Simplest way to fix that : declare an automatic array initialized with the string literal, and all is fine :
char thing[]="ssssssssssssssss++";
(an array and a pointer are not exactly the same ...)