From Power Up To Bash Prompt: Getty and Login

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## 10. Getty and Login

Getty is the program that enables you to log in through a serial device such as a virtual terminal, a text terminal, or a modem. It displays the login prompt. Once you enter your username, getty hands this over to `login` which asks for a password, checks it out and gives you a shell.

There are many getty's available. Some distributions, including Red Hat use a very small one called `mingetty` that only works with virtual terminals.

The `login` program is part of the util-linux package, which also contains a getty called `agetty`, which works fine. This package also contains `mkswap`, `fdisk`, `passwd`, `kill`, `setterm`, `mount`, `swapon`, `rdev`, `renice`, `more` (the program) and more (ie more programs).

## 10.1 Configuration

The message that comes on the top of your screen with your login prompt comes from `/etc/issue`. Gettys are usually started in `/etc/inittab`. Login checks user details in `/etc/passwd`, and if you have password shadowing, `/etc/shadow`.

## 10.2 Exercises

Create a `/etc/passwd` by hand. Passwords can be set to null, and changed with the program `passwd` once you log on. See the man page for this file Use `man 5 passwd` to get the man page for the file rather than the man page for the program.

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