Originální popis anglicky:
endservent, getservbyname, getservbyport, getservent, setservent - network
services database functions
Návod, kniha: POSIX Programmer's Manual
#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);
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 member 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.
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.
No errors are defined.
The following sections are informative.
None.
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 overwritten by
subsequent calls to any of these functions.
None.
None.
endhostent() ,
endprotoent() ,
htonl() ,
inet_addr()
, 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
.
