Originální popis anglicky:
endprotoent, getprotobyname, getprotobynumber, getprotoent, setprotoent -
network protocol database functions
Návod, kniha: POSIX Programmer's Manual
#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);
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 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 specified by
proto matches the
p_proto member, opening and closing a
connection 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 reentrant. A function that is not required to be
reentrant is not required to be thread-safe.
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.
No errors are defined.
The following sections are informative.
None.
The
getprotobyname(),
getprotobynumber(), and
getprotoent()
functions may return pointers to static data, which may be overwritten by
subsequent calls to any of these functions.
None.
None.
The Base Definitions volume of IEEE Std 1003.1-2001,
<netdb.h>
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, Copyright (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.opengroup.org/unix/online.html
.
