The getpw() function searches the user data base for a user id number that equals uid, copies the line of the password file in which uid
was found into the array pointed to by buf, and returns 0. getpw() returns non-zero if uid cannot be found.
This function is included only for compatibility with prior systems and should not be used; the functions described on the getpwnam(3C) manual page should be used instead.
If the /etc/passwd and the /etc/group files have a plus sign (+) for the NIS entry, then getpwent() and getgrent() will not return NULL when the end of file is reached. See getpwnam(3C).
