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GETPROTOENT(3)		     Library Functions Manual		  GETPROTOENT(3)

NAME
     getprotoent,  getprotobynumber, getprotobyname, setprotoent, endprotoent --
     get protocol entry

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <netdb.h>

     struct protoent *
     getprotoent(void);

     struct protoent *
     getprotobyname(const char *name);

     struct protoent *
     getprotobynumber(int proto);

     void
     setprotoent(int stayopen);

     void
     endprotoent(void);

DESCRIPTION
     The getprotoent(), getprotobyname(), and getprotobynumber() functions  each
     return  a	pointer to an object with the following structure containing the
     broken-out  fields  of  a	line  in  the  network	 protocol   data   base,
     /etc/protocols.

	   struct protoent {
		   char    *p_name;	   /* official name of protocol */
		   char    **p_aliases;    /* alias list */
		   int	   p_proto;	   /* protocol number */
	   };

     The members of this structure are:

     p_name	The official name of the protocol.

     p_aliases	A zero terminated list of alternate names for the protocol.

     p_proto	The protocol number.

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

     The setprotoent() 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
     getprotobyname() or getprotobynumber().

     The endprotoent() function closes the file.

     The getprotobyname() function and	getprotobynumber()  sequentially  search
     from  the	beginning of the file until a matching protocol name or protocol
     number is found, or until EOF is encountered.

RETURN VALUES
     Null pointer returned on EOF or error.

FILES
     /etc/protocols

SEE ALSO
     protocols(5)

HISTORY
     The getprotoent(), getprotobynumber(), getprotobyname(), setprotoent(), and
     endprotoent() functions appeared in 4.2BSD.

BUGS
     These functions use a thread-specific data space; if the data is needed for
     future use, it should be copied before any subsequent calls  overwrite  it.
     Only the Internet protocols are currently understood.

FreeBSD 14.3			  June 4, 1993			  GETPROTOENT(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=getprotoent&manpath=FreeBSD+14.3-RELEASE+and+Ports>

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