hostname ( )(7) Miscellaneous Information Manual hostname - (hostnames) ; -- , ; , <> <> <> <>. 1 63 , , , 253 . : ASCII(7) a z, 0 9 (-). . , , , ( , , getaddrinfo(3) gethostbyname(3)). Hostnames are resolved by the NSS framework in glibc according to the hosts configuration in nsswitch.conf(5). The DNS-based name resolver (in the dns NSS service module) resolves them in the following fashion. , , HOSTALIASES , , . , , ; , -- , . , . , . , . , , , 2 ( ). , cs.example.com lithium.cchem lithium.cchem.cs.example, lithium.cchem.example.com. lithium.cchem.com , . ( resolver(5)). . getaddrinfo(3), gethostbyname(3), nsswitch.conf(5), resolver(5), mailaddr(7), named(8) IETF RFC 1123 IETF RFC 1178 Yuri Kozlov ; GNU 3 , . . , , . Linux man-pages 6.06 11 2023 . hostname ( )(7)