C: expanding "~user" notation

Dark_Helmet · 02-27-2007, 02:14 AM

Does anyone know of a simple way to find the home directory of a user if the path is given as "~user/path/to/somewhere"? I'm looking for anything... personal code you've developed or a library routine you might know of.

I can't find anything appropriate with apropos and searching for "home directory program username" on Google still gives no meaningful results... not sure how else I could refine the search.

I can write a parsing routine, but don't want to reinvent the wheel, and I know the wheel has been invented somewhere out there.

I know I can call popen() with a piped sequence sequence of commands to pull the information out of /etc/passwd ("grep '^<username>:' /etc/passwd | cut -f 5 -d ':'"), but I want to leave that as a last resort.

I know the above might sound picky (maybe even a lot), but I would really appreciate any code or just a nudge in the right direction.

Thanks.

tread · 02-27-2007, 03:33 AM

Is getpwnam what you are looking for?
man getpwname shows:

Code:

struct passwd *getpwnam(const char *name); /* name is user name*/

struct passwd {
    char    *pw_name;      /* user name */
    char    *pw_passwd;    /* user password */
    uid_t   pw_uid;        /* user id */
    gid_t   pw_gid;        /* group id */
    char    *pw_gecos;     /* real name */
    char    *pw_dir;       /* home directory */
    char    *pw_shell;     /* shell program */
};

Guttorm · 02-27-2007, 08:26 AM

Hi

getenv("HOME") gives the home directory too.

Dark_Helmet · 02-27-2007, 09:27 AM

getpwnam() is exactly what I was looking for.

I use getenv() too, but if a user wants to specify another user's home directory, then getenv() won't work.

Thank you both.