Get user's home directory on Windows and POSIX operating systems

get_home_dir.c

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

#ifdef _WIN32
#include <windows.h>
#endif

const char* get_home_directory()
{
#ifdef _WIN32
    static char home_dir[MAX_PATH];

    if (GetEnvironmentVariable("USERPROFILE", home_dir, MAX_PATH))
    {
        return home_dir;
    }
    else
    {
        return NULL;
    }
#else
    return getenv("HOME");
#endif
}

int main()
{
    const char* home_dir = get_home_directory();

    if (home_dir != NULL)
    {
        printf("Home directory: %s\n", home_dir);
    }
    else
    {
        printf("Failed to get home directory.\n");
    }

    return 0;
}