SERVICES(4)                                                        SERVICES(4)


NAME
     services - service name database

DESCRIPTION
     The /etc/services file contains information regarding the known services
     available in the Internet.  For each service a single line should be
     present with the following information:

        + official service name

        + port number

        + protocol name

        + aliases (optional)

     Items are separated by any number of blanks and/or tab characters.  The
     port number and protocol name are considered a single item; a ``/'' is
     used to separate the port and protocol (e.g. ``512/tcp'').  A ``#''
     indicates the beginning of a comment; characters up to the end of the
     line are not interpreted by routines which search the file.

     Service names may contain any printable character other than a field
     delimiter, newline, or comment character.  For example,

          smtp    25/tcp    mail


DETERMINING USAGE
     It is sometimes useful to be able to determine which processes are using
     a particular port.  This can be accomplished using the fuser(1M) command.
     For example, in order to see which processes are listening on TCP port
     25, the command

          fuser 25/tcp

     can be used.  Note that fuser only accepts service names in their numeric
     form; symbolic names such as ``smtp'' cannot be used.

FILES
     /etc/services

     If the NFS option is installed and NIS is running, the getservent(3N)
     library routines only access this file if no entry was found in the NIS
     database.

SEE ALSO
     fuser(1M), getservent(3N)


BUGS
     A name server should be used instead of a static file.


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