How can I return a string properly in C

Question

I'm having a simple question to make, because I can't really find the way to return a string from a function and put it in another string. My code in C is this:

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

char *func();

int main()
{
        char *temp = malloc(sizeof(char) * 25);

        temp = func();
        printf("String received: %s\n", temp);

        return 0;
}

char *func()
{
        char str[25];

        strcpy(str, "HEY THERE!");
        printf("String sent: %s\n", str);

        return str;
}

I get this result: String sent: HEY THERE! String received:

Any idea how to do it properly? Thanks

score 2 · Accepted Answer · answered May 26 '14 at 14:44

2

Dynamic memory, yes, but it's used in the wrong place. Think about this code again:

char *temp = malloc(sizeof(char) * 25);
temp = func();

What you are doing is to allocate some memory for temp, and then assign it another value: the return value of func(), that's memory leak.

The correct method is to allocate memory in func(), and return the pointer to the allocated memory. Remember to free it when it's not used.

answered May 26 '14 at 14:44

Yu Hao

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I see what you say @Yu is totally correct. But still try to find the solution, temp seems empty again – STRATOSpeed May 26 '14 at 14:51
@STRATOSpeed You are now allocating memory for `str`, right? Like `char *str = malloc(25);` ? – Yu Hao May 26 '14 at 14:53
Ok ok Yes @Yu i found it thanks a lot! That was it :) – STRATOSpeed May 26 '14 at 14:55

How can I return a string properly in C

1 Answers1