Index for Section 3

Alphabetical listing for G

getservent(3)
NAME
  getservent, getservent_r - Get a services file entry from the /etc/services
  file.

LIBRARY
  Standard C Library (libc.so, libc.a)

SYNOPSIS
  #include <netdb.h>
  struct servent *getservent(void);

  [Digital]  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 getservent_r(
	  struct servent *serv,
	  struct servent_data *serv_data);

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

  getservent():	 XPG4-UNIX

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

PARAMETERS
  serv	    [Digital]  For getservent_r() only, this points to the servent
	    structure.	The netdb.h header file defines the servent
	    structure.

  serv_data [Digital]  For getservent_r() only, this  points to the
	    servent_data structure.  The netdb.h header file defines the
	    servent_data structure.

DESCRIPTION
  The getservent() (get service entry) function opens and reads the next line
  of either the local /etc/services file or the NIS distributed services file
  for the requested information.  To determine which file or files to search,
  and in which order, the system uses the switches in the /etc/svc.conf file.

  An application program can use the getservent() function to retrieve
  information about network services and the protocol ports they use.


  The getservent() function returns a pointer to a servent structure, which
  contains fields for a line of information from the network services
  database file.  The servent structure is defined in the netdb.h header file
  as follows:


       struct  servent {
	       char    *s_name;	       /* official service name */
	       char    **s_aliases;    /* alias list */
	       int     s_port;	       /* port # */
	       char    *s_proto;       /* protocol to use */
       };

  The network services database file remains open after a call by the
  getservent() function.  Use the endservent() function to close the network
  services database file.  Use the setservent() function to rewind.

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

  [Digital]  The getservent_r() function is an obsolete reentrant version of
  the getservent() 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 servent_data
  structure before its first access by the getservent_r() function.

RETURN VALUES
  Upon successful completion, the getservent() function returns a pointer to
  a servent structure.	If it fails or reaches the end of the network
  services database file, it returns a null pointer.

  [Digital]  Upon successful completion, the getservent_r() function stores
  the servent structure in the location pointed to by serv, 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 getservent()
  function.

  [Digital]  If any of the following conditions occurs, the getservent_r()
  function sets errno to the corresponding value:

  [EINVAL]  The serv or serv_data parameter is invalid.

  [ESRCH]   The search failed.

  [Digital]  In addition, if the function fails to open the file, it sets
  errno to indicate the cause of the failure.

FILES
  /etc/services
	    The DARPA Internet network service name database file. Each
	    record in the file occupies a single line and has four fields:
	    the official service name, the port number, the protocol name,
	    and aliases.

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


RELATED INFORMATION
  Functions: getservbyport(3), getservbyname(3), endservent(3),
  setservent(3).


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

  Networks: nis_intro(7).

  Standards: standards(5).