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GETSERVENT(3)	       FreeBSD Library Functions Manual		 GETSERVENT(3)

NAME
     getservent, getservent_r, getservbyport, getservbyport_r, getservbyname,
     getservbyname_r, setservent, setservent_r,	endservent, endservent_r --
     get service entry

SYNOPSIS
     #include <netdb.h>

     struct servent *
     getservent(void);

     int
     getservent_r(struct servent *servent, struct servent_data *servent_data);

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

     int
     getservbyname_r(const char	*name, const char *proto,
	 struct	servent	*servent, struct servent_data *servent_data);

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

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

     void
     setservent(int stayopen);

     void
     setservent_r(int stayopen,	struct servent_data *servent_data);

     void
     endservent(void);

     void
     endservent_r(struct servent_data *servent_data);

DESCRIPTION
     The getservent(), getservbyname(),	and getservbyport() functions each re-
     turn a pointer to an object with the following structure containing the
     broken-out	fields of a line in the	network	services database,
     /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 null-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 services database 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 (specified in network byte order) is found,	or until EOF is	en-
     countered.	 If a protocol name is also supplied (non-null), searches must
     also match	the protocol.

     The getservent_r(), getservbyport_r(), getservbyname_r(), setservent_r(),
     and endservent_r()	functions are reentrant	versions of the	above func-
     tions that	take a pointer to a servent_data structure which is used to
     store state information.  The structure must be zero-filled before	it is
     used and should be	considered opaque for the sake of portability.

     The getservent_r(), getservbyport_r(), and	getservbyname_r() functions
     also take a pointer to a servent structure	which is used to store the re-
     sults of the database lookup.

RETURN VALUES
     The getservent(), getservbyport(),	and getservbyname() functions return a
     pointer to	a servent structure on success or a null pointer if end-of-
     file is reached or	an error occurs.

     The getservent_r(), getservbyport_r(), and	getservbyname_r() functions
     return 0 on success or -1 if end-of-file is reached or an error occurs.

FILES
     /etc/services

SEE ALSO
     getprotoent(3), services(5)

STANDARDS
     The getservent(), getservbynumber(), getservbyname(), setservent(), and
     endservent() functions conform to IEEE Std	1003.1-2004 ("POSIX.1").

     The getservent_r(), getservbyport_r(), getservbyname_r(), setservent_r(),
     and endservent_r()	functions are not currently standardized.  This	imple-
     mentation follows the API used by HP, IBM,	and Digital.

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

     The getservent_r(), getservbyport_r(), getservbyname_r(), setservent_r(),
     and endservent_r()	functions appeared in OpenBSD 3.7.

BUGS
     The non-reentrant functions use static 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	13.0			 June 5, 2013			  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | FILES | SEE ALSO | STANDARDS | HISTORY | BUGS

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