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getprotobyname(3)
NAME
  getprotobyname, getprotobyname_r - Get a protocol entry by protocol name

SYNOPSIS
  #include <netdb.h>

  struct protoent *getprotobyname(
	  const char *name );

  [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 getprotobyname_r(
	  const char *name,
	  struct protoent *proto,
	  struct protoent_data *proto_data );

LIBRARY
  Standard C Library (libc)

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  getprotobyname():  XNS4.0, XNS5.0

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

PARAMETERS
  name
      Specifies the official protocol name or alias.

  proto
      [Tru64 UNIX]  For getprotobyname_r(), points to the protoent structure.
      The netdb.h header file defines the protoent structure.

  proto_data
      [Tru64 UNIX]  For getprotobyname_r(), is data for the protocols
      database. The netdb.h header file defines the protoent_data structure.

DESCRIPTION
  The getprotobyname() 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 the NIS network protocols 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 getprotobyname() function searches the network protocols database file
  sequentially until a match with the name parameter occurs. The name
  parameter will specify either the official protocol name or an alias. When
  EOF (End-of-File) is reached without a match, an error value is returned by
  this function.

  When using the getprotobyname() function, use the endprotoent() function to
  close the protocols file.

NOTES
  The getprotobyname() 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 getprotobyname_r() function is an obsolete reentrant
  version of the getprotobyname() 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 getprotobyname_r() function.

RETURN VALUES
  Upon successful completion, the getprotobyname() 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 getprotobyname_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.

ERRORS
  Current industry standards do not define error values for the
  getprotobyname() function.

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

  [EINVAL]
      The proto_data or proto parameter is invalid.

  [ESRCH]
      The search failed.

  In addition, if the getprotobyname() or getprotobyname_r() function fail to
  open the file, it sets errno to indicate the cause of the failure.

FILES
  /etc/protocols
      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.

  /etc/svc.conf
      The database service selection configuration file.

SEE ALSO
  Functions: getprotobynumber(3), getprotoent(3), setprotoent(3),
  endprotoent(3).

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

  Networks: nis_intro(7)

  Standards: standards(5)

  Network Programmer's Guide

Index for Section 3

Alphabetical listing for G

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