How can I get user name by user ID?
In my FTP client I can see files' owner ID (99).
How do I find out which user is the owner of these files?
Shorter getent version (as long as you don't need just the username)
$ getent passwd 99
nobody:x:99:99:Nobody:/:/sbin/nologin
Works on at least CentOS 5.6 - will take username or uid as key.
$ getent passwd | awk -F: '$3 == 99 { print $1 }'
nobody
The quickest way to check it (if you have a shell access) is to: cat /etc/passwd | grep 99
Btw UID 99 usually belongs to "nobody" user.