huschi.net

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 (consult 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 infor-
       mation 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 begin-
       ning and find the first entry for which the protocol 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 protocol number speci-
       fied by proto matches the p_proto member, opening and closing a connec-
       tion to the database as necessary.
       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 structure, 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 thread-safe.
RETURN VALUE
       Upon successful completion, getprotobyname(),  getprotobynumber(),  and
       getprotoent() return a pointer to a protoent 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.
       The application shall not modify the  structure  to  which  the  return
       value  points,  nor any storage areas pointed to by pointers within the
       structure. The returned pointer, and  pointers  within  the  structure,
       might  be  invalidated  or  the structure or the storage areas might be
       overwritten by a subsequent call  to  getprotobyname(),  getprotobynum-
       ber(), or getprotoent().
ERRORS
       No errors are defined.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       None.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       The Base Definitions volume of POSIX.1-2008, <netdb.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal  and  Electronics  Engineers,  Inc  and  The  Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum  1  applied.)  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.unix.org/online.html .
       Any typographical or formatting errors that appear  in  this  page  are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors,  see  https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                      ENDPROTOENT(3P)