hostname — Local hostname configuration file
/etc/hostname
The /etc/hostname
file configures the
name of the local system that is set during boot using the
sethostname(2)
system call. It should contain a single newline-terminated
hostname string. Comments (lines starting with a `#') are ignored.
The hostname may be a free-form string up to 64 characters in length;
however, it is recommended that it consists only of 7-bit ASCII lower-case
characters and no spaces or dots, and limits itself to the format allowed
for DNS domain name labels, even though this is not a strict
requirement.
Depending on the operating system, other configuration files might be checked for configuration of the hostname as well, however only as fallback.
You may use hostnamectl(1) to change the value of this file during runtime from the command line. Use systemd-firstboot(1) to initialize it on mounted (but not booted) system images.