Obtaining uid from username

JPrieSL · 04-16-2007, 10:11 AM

Hi all -

I need to obtain a Unix user id from a given username in C/C++, something along the lines of:

int GetUID( const char *username );

There seem to be ways of doing this with other languages, however I'm having trouble finding a way to do this from a standard C/C++ application.

Does anyone know of any unix api functions that may accomplish this?

Thanks in advance -
Josh

slzckboy · 04-16-2007, 10:52 AM

see if this helps

http://www.linuxquestions.org/questi...d.php?t=543727

JPrieSL · 04-18-2007, 08:04 AM

Hi - sorry for the delay in responding.

I saw this thread, however my problem is sort of the opposite direction. For any arbitrary username, I need to be able to extract the user ID. The previous thread would be great if I needed to go in the reverse direction, however I can't seem to determine how I could use that function, short of propagating all of the existing user IDs and matching the one which corresponds to the specified user name. Is there any better way to do this?

Thanks,
Josh

Guttorm · 04-18-2007, 08:09 AM

Hi

There's a similar function "getpwnam" that does what you want. It's in the same man page in my system. But it doesn't return uid but a pointer to a structure that contains it

struct passwd *pointer = getpwnam("username");
int uid = pointer->pw_uid;

JPrieSL · 04-20-2007, 08:31 AM

Thanks guys - getpwnam did the trick.

- Josh