When we execute the following code, we find that it displays the same number twice, even though the two users have different IDs in the password file. Why is this?
printf("%ld %ld\n", (long) (getpwnam("avr")->pw_uid), (long) (getpwnam("tsr")->pw_uid));Because getpwnam returns its result in a statically allocated buffer. The second call overwrites the result of the first call.
Implement getpwnam() using setpwent(), getpwent(), and endpwent().
see code in getpwnam.c