hostname — Local host name configuration file
/etc/hostname
The /etc/hostname file
configures the name of the local system that is set
during boot, with the
sethostname(2)
system call. It should contain a single
newline-terminated host name string. The
host name may be a free-form string up to 64 characters
in length, however it is recommended that it consists
only of 7bit 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 host name as well, however only as fallback.