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GETSERVENT(3)		    Library Functions Manual		 GETSERVENT(3)

NAME
       getservent, getservbyport, getservbyname, setservent, endservent	-- get
       service entry

LIBRARY
       Standard	C Library (libc, -lc)

SYNOPSIS
       #include	<netdb.h>

       struct servent *
       getservent();

       struct servent *
       getservbyname(const char	*name, const char *proto);

       struct servent *
       getservbyport(int port, const char *proto);

       void
       setservent(int stayopen);

       void
       endservent(void);

DESCRIPTION
       The  getservent(),  getservbyname(), and	getservbyport()	functions each
       return a	pointer	to an object with the following	 structure  containing
       the  broken-out	fields	of  a  line in the network services data base,
       /etc/services.

	     struct servent {
		     char    *s_name;	     /*	official name of service */
		     char    **s_aliases;    /*	alias list */
		     int     s_port;	     /*	port service resides at	*/
		     char    *s_proto;	     /*	protocol to use	*/
	     };

       The members of this structure are:

       s_name	  The official name of the service.

       s_aliases  A zero terminated list of alternate names for	the service.

       s_port	  The port number at which the service resides.	 Port  numbers
		  are returned in network byte order.

       s_proto	  The name of the protocol to use when contacting the service.

       The  getservent() function reads	the next line of the file, opening the
       file if necessary.

       The setservent()	function opens and rewinds the file.  If the  stayopen
       flag  is	non-zero, the net data base will not be	closed after each call
       to getservbyname() or getservbyport().

       The endservent()	function closes	the file.

       The getservbyname() and getservbyport() functions  sequentially	search
       from  the  beginning of the file	until a	matching protocol name or port
       number (which must be specified in network byte order) is found,	or un-
       til EOF is encountered.	If a protocol  name  is	 also  supplied	 (non-
       NULL), searches must also match the protocol.

FILES
       /etc/services
       /var/db/services.db

DIAGNOSTICS
       Null pointer returned on	EOF or error.

SEE ALSO
       getprotoent(3), services(5), services_mkdb(8)

HISTORY
       The  getservent(),  getservbyport(), getservbyname(), setservent(), and
       endservent() functions appeared in 4.2BSD.

BUGS
       These functions use a thread-specific data  storage;  if	 the  data  is
       needed  for future use, it should be copied before any subsequent calls
       overwrite it.  Expecting	port numbers to	fit in a 32  bit  quantity  is
       probably	naive.

FreeBSD	13.2		       December	7, 2020			 GETSERVENT(3)
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | FILES | DIAGNOSTICS | SEE ALSO | HISTORY | BUGS

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