Thread: simple pointer and struct question

Pretty much all of the code here has one or more flaws. I'll demonstrate "working" versions.

There are several ways of doing this.
One way:

Code:

#include<stdio.h>

typedef struct
{
    char format_name[64];
}
StupidRec;

int main(int argc, char** argv)
{
    StupidRec* list = malloc(sizeof(StupidRec));
    strcpy(list->format_name, "hello");
    printf("%s\n", list->format_name);
    free(list); // DON'T FORGET!
    return 0;
}

Another way:

Code:

#include<stdio.h>

typedef struct
{
    const char* format_name;
}
StupidRec;

int main(int argc, char** argv)
{
    StupidRec list;
    list.format_name = "hello"; // NOTE: CAN'T MODIFY STRING
    printf("%s\n", list.format_name);
    return 0;
}

A third way:

Code:

#include<stdio.h>

typedef struct
{
    char* format_name;
}
StupidRec;

int main(int argc, char** argv)
{
    char buf[1024];
    StupidRec* list = malloc(sizeof(StupidRec));
    list->format_name = buf; // SET POINTER TO A VALID STORAGE FIRST
    strcpy(list->format_name, "hello"); // DANGEROUS, BUT WE KNOW "hello" DO NOT TAKE UP 1024 CHARACTERS.
    printf("%s\n", list->format_name);
    free(list); // DON'T FORGET!
    return 0;
}

And finally, here is how to NOT do it:

Code:

#include<stdio.h>

typedef struct
{
    char* format_name;
}
StupidRec;

int main(int argc, char** argv)
{
    StupidRec list;
    list.format_name = malloc(1024);
    list.format_name = "hello"; // MEMORY LEAK. DON'T DO THIS.
    printf("%s\n", list.format_name);
    return 0;
}

Note how I don't use the StupidList type. It's confusing only to typedef pointers that way. Avoid it.

Originally Posted by CommonTater

LOL... tell that to the windows crew....
Thousands and thousands of structs, defined exactly as the OP and I did it.

Doesn't mean it's a good idea.
Windows also uses hungarian notation, which we know we love to hate.
You may be used to it, but don't drag others into that foolishness. It hurts readability.