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agetty — Alternative `getty`: Open a `tty` port, prompt for a login name, and invoke the `/bin/login` command

Submitted by: @import:tldr-pages·Mar 2, 2026·

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portcommandttygettyalternativecliopenagetty

linux

Problem

How to use the agetty command: Alternative getty: Open a tty port, prompt for a login name, and invoke the /bin/login command. It is normally invoked by init. Note: The baud rate is the speed of data transfer between a terminal and a device over a serial connection. More information: <https://manned.org/agetty>.

Solution

agetty — Alternative getty: Open a tty port, prompt for a login name, and invoke the /bin/login command. It is normally invoked by init. Note: The baud rate is the speed of data transfer between a terminal and a device over a serial connection. More information: <https://manned.org/agetty>.

Connect stdin to a port (relative to /dev) and optionally specify a baud rate (defaults to 9600):

agetty {{tty}} {{115200}}

Assume stdin is already connected to a tty and set a timeout for the login:

agetty {{[-t|--timeout]}} {{timeout_in_seconds}} -

Assume the tty is 8-bit, overriding the $TERM environment variable set by init:

agetty {{[-8|--8bits]}} - {{term_var}}

Skip the login (no login) and invoke, as root, another login program instead of /bin/login:

agetty {{[-n|--skip-login]}} {{[-l|--login-program]}} {{login_program}} {{tty}}

Do not display the pre-login (issue) file (/etc/issue by default) before writing the login prompt:

agetty {{[-i|--noissue]}} -

Change the root directory and write a specific fake host into the utmp file:

agetty {{[-r|--chroot]}} /{{path/to/root_directory}} {{[-H|--host]}} {{fake_host}} -

Code Snippets

Connect `stdin` to a port (relative to `/dev`) and optionally specify a baud rate (defaults to 9600)

agetty {{tty}} {{115200}}

Assume `stdin` is already connected to a `tty` and set a timeout for the login

agetty {{[-t|--timeout]}} {{timeout_in_seconds}} -

Assume the `tty` is 8-bit, overriding the `$TERM` environment variable set by `init`

agetty {{[-8|--8bits]}} - {{term_var}}

Skip the login (no login) and invoke, as root, another login program instead of `/bin/login`

agetty {{[-n|--skip-login]}} {{[-l|--login-program]}} {{login_program}} {{tty}}

Do not display the pre-login (issue) file (`/etc/issue` by default) before writing the login prompt

agetty {{[-i|--noissue]}} -

Context

tldr-pages: linux/agetty

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