SERVICES man page on Scientific

Man page or keyword search:  
man Server   26626 pages
apropos Keyword Search (all sections)
Output format
Scientific logo
[printable version]

SERVICES(5)		   Linux Programmer's Manual		   SERVICES(5)

       services - Internet network services list

       services	 is  a	plain  ASCII  file  providing a mapping between human-
       friendly textual names for  internet  services,	and  their  underlying
       assigned	 port  numbers	and  protocol types.  Every networking program
       should look into this file to get the port number  (and	protocol)  for
       its  service.   The C library routines getservent(3), getservbyname(3),
       getservbyport(3), setservent(3),	 and  endservent(3)  support  querying
       this file from programs.

       Port  numbers  are  assigned  by	 the  IANA  (Internet Assigned Numbers
       Authority), and their current policy is to assign both TCP and UDP pro‐
       tocols when assigning a port number.  Therefore, most entries will have
       two entries, even for TCP-only services.

       Port numbers below 1024 (so-called "low numbered" ports)	 can  only  be
       bound to by root (see bind(2), tcp(7), and udp(7)).  This is so clients
       connecting to low numbered ports can trust that the service running  on
       the port is the standard implementation, and not a rogue service run by
       a user of the machine.  Well-known port numbers specified by  the  IANA
       are normally located in this root-only space.

       The  presence  of  an entry for a service in the services file does not
       necessarily mean that the service is currently running on the  machine.
       See  inetd.conf(5)  for the configuration of Internet services offered.
       Note that not all networking services are started by inetd(8),  and  so
       won't  appear  in  inetd.conf(5).   In particular, news (NNTP) and mail
       (SMTP) servers are often initialized from the system boot scripts.

       The location of the services  file  is  defined	by  _PATH_SERVICES  in
       <netdb.h>.  This is usually set to /etc/services.

       Each line describes one service, and is of the form:

	      service-name   port/protocol   [aliases ...]


		 is  the  friendly  name the service is known by and looked up
		 under.	 It is case sensitive.	Often, the client  program  is
		 named after the service-name.

       port	 is the port number (in decimal) to use for this service.

       protocol	 is  the type of protocol to be used.  This field should match
		 an entry in the protocols(5) file.   Typical  values  include
		 tcp and udp.

       aliases	 is an optional space or tab separated list of other names for
		 this service (but see the BUGS section	 below).   Again,  the
		 names are case sensitive.

       Either spaces or tabs may be used to separate the fields.

       Comments are started by the hash sign (#) and continue until the end of
       the line.  Blank lines are skipped.

       The service-name should begin in the first column of  the  file,	 since
       leading	spaces	are  not stripped.  service-names can be any printable
       characters excluding space and tab.  However, a conservative choice  of
       characters  should  be  used to minimize compatibility problems.	 E.g.,
       a-z, 0-9, and hyphen (-) would seem a sensible choice.

       Lines not matching this format should  not  be  present	in  the	 file.
       (Currently,  they  are  silently	 skipped  by getservent(3), getservby‐
       name(3), and getservbyport(3).  However, this behavior  should  not  be
       relied on.)

       This file might be distributed over a network using a network-wide nam‐
       ing service like Yellow Pages/NIS or BIND/Hesiod.

       A sample services file might look like this:

	      netstat	      15/tcp
	      qotd	      17/tcp	      quote
	      msp	      18/tcp	      # message send protocol
	      msp	      18/udp	      # message send protocol
	      chargen	      19/tcp	      ttytst source
	      chargen	      19/udp	      ttytst source
	      ftp	      21/tcp
	      # 22 - unassigned
	      telnet	      23/tcp

	      The Internet network services list

	      Definition of _PATH_SERVICES

       listen(2), endservent(3), getservbyname(3),  getservbyport(3),  getser‐
       vent(3), setservent(3), inetd.conf(5), protocols(5), inetd(8)

       Assigned Numbers RFC, most recently RFC 1700, (AKA STD0002)

       This  page  is  part of release 3.22 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at

Linux				  2008-09-23			   SERVICES(5)

List of man pages available for Scientific

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net