ENDPROTOENT(3P)                                     POSIX Programmer's Manual                                    ENDPROTOENT(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
       endprotoent, getprotobyname, getprotobynumber, getprotoent, setprotoent - network protocol database functions

SYNOPSIS
       #include <netdb.h>

       void endprotoent(void);
       struct protoent *getprotobyname(const char *name);
       struct protoent *getprotobynumber(int proto);
       struct protoent *getprotoent(void);
       void setprotoent(int stayopen);


DESCRIPTION
       These  functions  shall  retrieve  information about protocols. 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 setprotoent() 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 connection to the network protocol database shall not be closed after each call to
       getprotoent() (either directly, or indirectly through one of the other getproto*() functions), and the implementation may
       maintain an open file descriptor for the database.

       The  getprotobyname() function shall search the database from the beginning and find the first entry for which the proto-
       col name specified by name matches the p_name member, opening and closing a connection to the database as necessary.

       The getprotobynumber() function shall search the database from the beginning and find the first entry for which the  pro-
       tocol  number  specified  by proto matches the p_proto member, opening and closing a connection to the database as neces-
       sary.

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

       The  getprotobyname(),  getprotobynumber(),  and getprotoent() functions shall each return a pointer to a protoent struc-
       ture, the members of which shall contain the fields of an entry in the network protocol database.

       The endprotoent() function shall close the connection to 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, getprotobyname(), getprotobynumber(), and getprotoent() return a pointer to a protoent struc-
       ture  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 getprotobyname(), getprotobynumber(), and getprotoent() functions may return pointers to static data,  which  may  be
       overwritten by subsequent calls to any of these functions.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       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                                               ENDPROTOENT(3P)