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ENDNETENT(3P) POSIX Programmer's Manual ENDNETENT(3P)
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.
endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent — network
database functions
#include <netdb.h>
void endnetent(void);
struct netent *getnetbyaddr(uint32_t net, int type);
struct netent *getnetbyname(const char *name);
struct netent *getnetent(void);
void setnetent(int stayopen);
These functions shall retrieve information about networks. 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 setnetent() function shall open and rewind the database. If the
stayopen argument is non-zero, the connection to the net database
shall not be closed after each call to getnetent() (either directly,
or indirectly through one of the other getnet*() functions), and the
implementation may maintain an open file descriptor to the database.
The getnetent() function shall read the next entry of the database,
opening and closing a connection to the database as necessary.
The getnetbyaddr() function shall search the database from the
beginning, and find the first entry for which the address family
specified by type matches the n_addrtype member and the network
number net matches the n_net member, opening and closing a connection
to the database as necessary. The net argument shall be the network
number in host byte order.
The getnetbyname() function shall search the database from the
beginning and find the first entry for which the network name
specified by name matches the n_name member, opening and closing a
connection to the database as necessary.
The getnetbyaddr(), getnetbyname(), and getnetent() functions shall
each return a pointer to a netent structure, the members of which
shall contain the fields of an entry in the network database.
The endnetent() function shall close the database, releasing any open
file descriptor.
These functions need not be thread-safe.
Upon successful completion, getnetbyaddr(), getnetbyname(), and
getnetent() shall return a pointer to a netent 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 shall be 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 getnetbyaddr(), getnetbyname(),
or getnetent().
No errors are defined.
The following sections are informative.
None.
None.
None.
None.
The Base Definitions volume of POSIX.1‐2008, netdb.h(0p)
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 Electrical 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.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 ENDNETENT(3P)
Pages that refer to this page: netdb.h(0p), getnetbyaddr(3p), inet_addr(3p), setnetent(3p)