FreeBSD Man Pages

getservbyport(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.
     /etc/services

DIAGNOSTICS

     Null pointer (0) returned on EOF or error.

SEE ALSO

     getprotoent(3), services(5)

HISTORY

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

BUGS

     These 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 5.4			 July 9, 1995			   FreeBSD 5.4

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