getprotobynumber man page on DigitalUNIX

Man page or keyword search:  
man Server   12896 pages
apropos Keyword Search (all sections)
Output format
DigitalUNIX logo
[printable version]

getprotobynumber(3)					   getprotobynumber(3)

       getprotobynumber, getprotobynumber_r - Get a protocol entry by number

       #include <netdb.h>

       struct protoent *getprotobynumber(
	       int num );

       [Tru64  UNIX]  The following obsolete function is supported in order to
       maintain backward compatibility with previous versions of the operating
       system.	You should not use it in new designs.  int getprotobynumber_r(
	       int num,
	       struct protoent *proto,
	       struct protoent_data *proto_data );

       Standard C Library (libc)

       Interfaces  documented on this reference page conform to industry stan‐
       dards as follows:

       getprotobyname():  XNS4.0, XNS5.0

       Refer to the standards(5) reference page	 for  more  information	 about
       industry standards and associated tags.

       Specifies  the protocol number.	[Tru64 UNIX]  For getprotobynumber_r()
       only, this points to the protoent structure.  The netdb.h  header  file
       defines the protoent structure.	[Tru64 UNIX]  For getprotobynumber_r()
       only, this is data for the protocols database.  The netdb.h header file
       defines the protoent_data structure.

       The  getprotobynumber()	function  returns  a pointer to a structure of
       type protoent. Its members specify data in fields from a record line in
       either  the local /etc/protocols file or NIS distributed network proto‐
       cols database file. To determine which file or files to search, and  in
       which  order,  the  system uses the switches in the /etc/svc.conf file.
       The netdb.h header file defines the protoent structure.

       The getprotobynumber() function searches the network protocols database
       file  sequentially until a match with the num parameter occurs. The num
       parameter must specify the official protocol number. When EOF  (End-Of-
       File)  is  reached  without a match, a null pointer is returned by this

       When using the getprotobynumber() function, use the endprotoent() func‐
       tion to close the protocols file.

       The  getprotobynumber()	function  returns a pointer to thread-specific
       data.  Subsequent calls to this or a related  function  from  the  same
       thread overwrite this data.

       [Tru64  UNIX]  The  getprotobynumber_r()	 function is an obsolete reen‐
       trant version of the getprotobynumber() function.  It is	 supported  in
       order  to maintain backward compatibility with previous versions of the
       operating system and should not be used in new designs.	Note that  you
       must  zero-fill	the  proto_data	 structure  before its first access by
       either the setprotoent_r() or getprotobynumber_r() functions.

       Upon successful completion, the getprotobynumber() function  returns  a
       pointer to a protoent structure.	 If it fails or reaches the end of the
       network protocols database file, it returns a null pointer.

       [Tru64  UNIX]  Upon  successful	completion,  the  getprotobynumber_r()
       function	 stores	 the  protoent structure in the location pointed to by
       proto, and returns a value of 0 (zero).	Upon  failure,	it  returns  a
       value of -1.

       Current industry standards do not define error values for the getproto‐
       bynumber() function.

       [Tru64 UNIX]  If any of the following conditions occurs, the  getproto‐
       bynumber_r() function sets errno to the corresponding value:

       The proto_data or proto parameter is invalid.  The search failed.

       In addition, if the getprotobynumber() or getprotobynumber_r() function
       fails to open the file, it sets errno to	 indicate  the	cause  of  the

       The  Internet  network protocols name database file. Each record in the
       file occupies a single line and has three fields: the official protocol
       name,  the protocol number, and protocol aliases.  The database service
       selection configuration file.

       Functions: getprotobyname(3), getprotoent(3),  setprotoent(3),  endpro‐

       Files: protocols(4), svc.conf(4).

       Networks: nis_intro(7).

       Standards: standards(5).

       Network Programmer's Guide


List of man pages available for DigitalUNIX

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net