Question

I have two .c files that I would like to compile into on executable. Having just started learning C, I’m finding it tricky to know how to transfer text as an argument between functions (which I’ve found to be incredibly simple in every other language).

Here are the two files:

Program.c

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

int main(){

char temp[40] = stringCall();
printf("%s",temp);

}

StringReturn.c

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

char[] stringCall(){

char toReturn[40] = "Hello, Stack Overflow!";
return toReturn;

}

I usually get a problem that says something like “Segmentation Failed (core dumped)” or alike. I’ve done a lot of Googling and amazing I can’t really find a solution, and certainly no simple tutorial “This is how to move text between functions”.

Any help would be appreciated 🙂

Answer 1

char toReturn[40] = "Hello, Stack Overflow!";
return toReturn;

This is invalid, you’re returning an auto array which gets out of scope after the function returns – this invokes undefined behavior. Try returning the string literal itself (it’s valid throughout the program):

return "Hello, Stack Overflow!";

Or a dynamic duplicate of your array:

char toReturn[40] = "Hello, Stack Overflow!";
return strdup(toReturn);

In this latter case, you’ll need to free() the string in the caller function.