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.Note that thedefault is to look first for a, and then mx, except that if the verbose option is turned on, the default is only a.The option -a (for all ) is equivalent to -v -t any.The option -l causes a listing of a complete domain.For example,host -l rutgers.eduwill give a listing of all hosts in the rutgers.edu domain.The -t option is used to filter what information is presented, as youwould expect.The default is address information, which also include PTR and NS records.The command host:-l -v -t any rutgers.eduwill give a complete download of the zone data for rutgers.edu, in the official master file format.(However the SOA recordis listed twice, for arcane reasons.)NOTE-l is implemented by doing a complete zone transfer and then filtering out the information you have asked for.Thiscommand should be used only if it is absolutely necessary.CUSTOMIZING HOSTNAME LOOKUPIn general, if the name supplied by the user does not have any dots in it, a default domain is appended to the end.Thisdomain can be defined in /etc/resolv.conf, but is normally derived by taking the local hostname after its first dot.The usercan override this, and specify a different default domain, using the environment variable LOCALDOMAIN.In addition, the usercan supply his own abbreviations for hostnames.They should be in a file consisting of one line per abbreviation.Each linecontains an abbreviation, a space, and then the full hostname.This file must be pointed to by an environment variableHOSTALIASES, which is the name of the file.SEE ALSOnamed(8)BUGSUnexpected effects can happen when you type a name that is not part of the local domain.Please always keep in mind thatthe local domain name is tacked onto the end of every name, unless it ends in a dot.Only if this fails is the name usedunchanged.The -l option only tries the first name server listed for the domain that you have requested.If this server is dead, you mayneed to specify a server manually.For example, to get a listing of foo.edu, you could try host -t ns foo.edu to get a list of allthe name servers for foo.edu, and then try host -l foo.edu xxx for all xxx on the list of name servers, until you find one thatworks.hostidhostid Set or print system s host ID.SYNTAXhostid [ v] [ decimal-id ] hostname259DESCRIPTIONThe hostid command prints the current host ID number in hexadecimal and both decimal and hexadecimal in parenthesis ifthe v option is given.This numeric value is expected to be unique across all hosts and is normally set to resemble the host sInternet address.Only the superuser can set the hostid by giving an argument.This value is stored in the file /etc/hostid and need only beperformed once.AUTHORhostid is written by Mitch D Souza (m.dsouza@mrc-apu.cam.ac.uk).SEE ALSOgethostid(2), sethostid(2)hostnamehostname Show or set the system s hostnamednsdomainname--Show the system s domain nameSYNOPSIShostname [ d][--domain][ Ffilename] [--filefilename] [ f][--fqdn][ h][--help][--long][ s][--short][ v][--version][name]dnsdomainnameDESCRIPTIONhostname is the program that is used to either set the hostname or display the current host or domain name of the system.This name is used by many of the networking programs to identify the machine.When called without any arguments, the program displays the current name as set by the hostname command.You canchange the output format to display always the short or the long hostname (FQDN).When called with arguments, theprogram will set the value of the hostname to the value specified.This usually is done only once, at system startup time, bythe /etc/rc.d/rc.inet1 configuration script.Note that only the superuser can change the hostname.If the program was called as dnsdomainname, it will show the domain name server (DNS) domain name.You can t change theDNS domain name with dnsdomainname.(See the following subsection.)OPTIONS d, --domain Display the name of the DNS domain.Don t use the com-mand domainname to get the DNSdomain name because it will show the NIS domain name and not the DNS domain name. F, --file filename Read the hostname from the specified file.Comments (lines starting with a #) are ignored. f, --fqdn, --long Display the FQDN (fully-qualified domain name).An FQDN consists of a short hostname andthe DNS domain name.Unless you are using bind or NIS for host lookups, you can change theFQDN and the DNS domain name (which is part of the FQDN) in the /etc/hosts file. h, --help Print a usage message on standard output and exit successfully. s, --short Display the short hostname. v, --version Print version information on standard output and exit successfully.FILES/etc/hosts Part I: User Commands260AUTHORPeter Tobias, (tobias@server.et-inf.fho-emden.de)Linux, 28 July 1994hpcdtoppm v0.3hpcdtoppm v0.3 Convert a Photo-CD file into a portable pixmapSYNOPSIShpcdtoppm [options] pcd-file [ppm-file]DESCRIPTIONhpcdtoppm reads a Photo-CD image file or overview file, and outputs a portable pixmap [ Pobierz całość w formacie PDF ]