Question

I need a way to get user home directory in C++ program running on Linux. If the same code works on Unix, it would be nice. I don’t want to use HOME environment value.

AFAIK, root home directory is /root. Is it OK to create some files/folders in this directory, in the case my program is running by root user?

Answer 1

You need getuid to get the user id of the current user and then getpwuid to get the password entry (which includes the home directory) of that user:

#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>

struct passwd *pw = getpwuid(getuid());

const char *homedir = pw->pw_dir;

Note: if you need this in a threaded application, you’ll want to use getpwuid_r instead.