ENDSERVENT(3P)                                      POSIX Programmer's Manual                                     ENDSERVENT(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       endservent, getservbyname, getservbyport, getservent, setservent - network services database functions

SYNOPSIS
       #include <netdb.h>

       void endservent(void);
       struct servent *getservbyname(const char *name, const char *proto);
       struct servent *getservbyport(int port, const char *proto);
       struct servent *getservent(void);
       void setservent(int stayopen);


DESCRIPTION
       These  functions  shall  retrieve  information  about network services.  This information is considered to be stored in a
       database that can be accessed sequentially or randomly. The implementation of this database is unspecified.

       The setservent() function shall open a connection to the database, and set the next entry to  the  first  entry.  If  the
       stayopen  argument is non-zero, the net database shall not be closed after each call to the getservent() function (either
       directly, or indirectly through one of the other getserv*() functions), and the implementation may maintain an open  file
       descriptor for the database.

       The  getservent() function shall read the next entry of the database, opening and closing a connection to the database as
       necessary.

       The getservbyname() function shall search the database from the beginning and find the first entry for which the  service
       name  specified  by  name  matches the s_name member and the protocol name specified by proto matches the s_proto member,
       opening and closing a connection to the database as necessary. If proto is a null pointer, any value of the s_proto  mem-
       ber shall be matched.

       The  getservbyport()  function  shall  search the database from the beginning and find the first entry for which the port
       specified by port matches the s_port member and the protocol name specified by proto matches the s_proto member,  opening
       and  closing a connection to the database as necessary. If proto is a null pointer, any value of the s_proto member shall
       be matched. The port argument shall be in network byte order.

       The getservbyname(), getservbyport(), and getservent() functions shall each return a pointer to a servent structure,  the
       members of which shall contain the fields of an entry in the network services database.

       The endservent() function shall close the database, releasing any open file descriptor.

       These functions need not be reentrant. A function that is not required to be reentrant is not required to be thread-safe.

RETURN VALUE
       Upon successful completion, getservbyname(), getservbyport(), and getservent() return a pointer to a servent structure if
       the requested entry was found, and a null pointer if the end of the database was reached or the requested entry  was  not
       found. Otherwise, a null pointer is returned.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       The port argument of getservbyport() need not be compatible with the port values of all address families.

       The  getservbyname(),  getservbyport(), and getservent() functions may return pointers to static data, which may be over-
       written by subsequent calls to any of these functions.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       endhostent(), endprotoent(), htonl(), inet_addr(), the Base Definitions volume of IEEE Std 1003.1-2001, <netdb.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                ENDSERVENT(3P)