hostnameutils man page

gethostname -
get local hostname.
gethostbyname -
get local host information for specified hostname.
gethostbyaddr -
get hostname via IP address.
getservbyname -
get configured port number of service

Syntax

gethostname [-help|-name|-aname|-all]

gethostbyname [-help|-name|-aname|-all] <name>

gethostbyaddr [-help|-name|-aname|-all] <ip>

getservbyname [-help|-number] <service>

Description

gethostname and gethostbyname are used to get the local resolved host name. gethostbyaddr is used to get the hostname of a specified IP address (dotted decimal notation). getservbyname can be used to get the configured port number of a service (e.g. from /etc/services).

The hostname utils are primarily used by the Sun Grid Engine installation scripts. gethostname , gethostbyname and gethostbyaddr called without any option will print out the hostname, all specified aliases, and the IP address of the locally resolved hostname. Calling getservbyname without any option will print out the full service entry.

Options

-help

Prints a list of all options.

-name

This option only reports the primary name of the host.

-aname

If this option is set, the Sun Grid Engine host alias file is used for host name resolving. It is necessary to set the environment variable SGE_ROOT and, if more than one cell is defined, also SGE_CELL.

This option will print out the Sun Grid Engine host name.

-all

By using the -all option all available host information will be printed. This information includes the host name, the Sun Grid Engine host name, all host aliases, and the IP address of the host.

-number

This option will print out the port number of the specified service name.

<name>

The host name for which the information is requested.

<ip>

The IP address (dotted decimal notation) for which the information is requested.

<service>

The service name for which the information is requested (e.g. ftp, sge_qmaster or sge_execd).

Examples

The following example shows how to get the port number of the FTP service:

>getservbyname -number ftp
21

The next example shows the output of gethostname -all when the host alias file contains this line:

gridmaster extern_name extern_name.mydomain

The local host resolving must also provide the alias name "gridmaster". Each Sun Grid Engine host that wants to use the cluster must be able to resolve the host name "gridmaster".

To setup an alias name, edit your /etc/hosts file or modify your NIS setup to provide the alias for the NIS clients.

The host alias file must be readable from each host (use e.g. NFS shared file location).

>gethostname -all
Hostname: extern_name.mydomain
SGE name: gridmaster
Aliases:  loghost gridmaster
Host Address(es): 192.168.143.99

Environmental Variables

SGE_ROOT
Specifies the location of the Sun Grid Engine standard configuration files.
SGE_CELL
If set, specifies the default Sun Grid Engine cell.

See Also

sge_intro(1), host_aliases(5),

Referenced By

libbind_resolver(5).

gethostbyaddr(1), gethostbyname(1), gethostname(1) and getservbyname(1) are aliases of hostnameutils(1).

$Date: 2009/03/12 16:06:25 $ SGE 6.2u5 Sun Grid Engine User Commands