1ENDNETENT(3P) POSIX Programmer's Manual ENDNETENT(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent - network
13 database functions
14
16 #include <netdb.h>
17 void endnetent(void);
19 struct netent *getnetbyaddr(uint32_t net, int type);
20 struct netent *getnetbyname(const char *name);
21 struct netent *getnetent(void);
22 void setnetent(int stayopen);
23
26 These functions shall retrieve information about networks. This infor‐
27 mation is considered to be stored in a database that can be accessed
28 sequentially or randomly. The implementation of this database is
29 unspecified.
30 The setnetent() function shall open and rewind the database. If the
32 stayopen argument is non-zero, the connection to the net database shall
33 not be closed after each call to getnetent() (either directly, or indi‐
34 rectly through one of the other getnet*() functions), and the implemen‐
35 tation may maintain an open file descriptor to the database.
36 The getnetent() function shall read the next entry of the database,
38 opening and closing a connection to the database as necessary.
39 The getnetbyaddr() function shall search the database from the begin‐
41 ning, and find the first entry for which the address family specified
42 by type matches the n_addrtype member and the network number net
43 matches the n_net member, opening and closing a connection to the data‐
44 base as necessary. The net argument shall be the network number in
45 host byte order.
46 The getnetbyname() function shall search the database from the begin‐
48 ning and find the first entry for which the network name specified by
49 name matches the n_name member, opening and closing a connection to the
50 database as necessary.
51 The getnetbyaddr(), getnetbyname(), and getnetent() functions shall
53 each return a pointer to a netent structure, the members of which shall
54 contain the fields of an entry in the network database.
55 The endnetent() function shall close the database, releasing any open
57 file descriptor.
58 These functions need not be reentrant. A function that is not required
60 to be reentrant is not required to be thread-safe.
61
63 Upon successful completion, getnetbyaddr(), getnetbyname(), and getne‐
64 tent() shall return a pointer to a netent structure if the requested
65 entry was found, and a null pointer if the end of the database was
66 reached or the requested entry was not found. Otherwise, a null pointer
67 shall be returned.
68
70 No errors are defined.
71 The following sections are informative.
73
75 None.
76
78 The getnetbyaddr(), getnetbyname(), and getnetent() functions may
79 return pointers to static data, which may be overwritten by subsequent
80 calls to any of these functions.
81
83 None.
84
86 None.
87
89 The Base Definitions volume of IEEE Std 1003.1-2001, <netdb.h>
90
92 Portions of this text are reprinted and reproduced in electronic form
93 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
94 -- Portable Operating System Interface (POSIX), The Open Group Base
95 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
96 Electrical and Electronics Engineers, Inc and The Open Group. In the
97 event of any discrepancy between this version and the original IEEE and
98 The Open Group Standard, the original IEEE and The Open Group Standard
99 is the referee document. The original Standard can be obtained online
100 at http://www.opengroup.org/unix/online.html .
101IEEE/The Open Group 2003 ENDNETENT(3P)