Manpage of GETNETENT

GETNETENT

Section: Linux Programmer's Manual (3)
Updated: 2015-08-08
Index
 

NAME

getnetent, getnetbyname, getnetbyaddr, setnetent, endnetent - get network entry  

SYNOPSIS

#include <netdb.h>struct netent *getnetent(void);struct netent *getnetbyname(const char *name);struct netent *getnetbyaddr(uint32_t net, int type);void setnetent(int stayopen);void endnetent(void);
 

DESCRIPTION

The getnetent() function reads the next entry from the networks database and returns a netentstructure containing the broken-out fields from the entry. A connection is opened to the database if necessary.

The getnetbyname() function returns a netentstructure for the entry from the database that matches the network name.

The getnetbyaddr() function returns a netentstructure for the entry from the database that matches the network number netof type type. The netargument must be in host byte order.

The setnetent() function opens a connection to the database, and sets the next entry to the first entry. If stayopenis nonzero, then the connection to the database will not be closed between calls to one of the getnet*() functions.

The endnetent() function closes the connection to the database.

The netentstructure is defined in <netdb.h>as follows:

struct netent {
    char      *n_name;     /* official network name */
    char     **n_aliases;  /* alias list */
    int        n_addrtype; /* net address type */
    uint32_t   n_net;      /* network number */
}

The members of the netentstructure are:

n_name
The official name of the network.
n_aliases
A NULL-terminated list of alternative names for the network.
n_addrtype
The type of the network number; always AF_INET.
n_net
The network number in host byte order.
 

RETURN VALUE

The getnetent(), getnetbyname() and getnetbyaddr() functions return a pointer to a statically allocated netentstructure, or a null pointer if an error occurs or the end of the file is reached.  

FILES

/etc/networks
networks database file
 

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
getnetent() Thread safetyMT-Unsafe race:netent
race:netentbuf env locale
getnetbyname() Thread safetyMT-Unsafe race:netbyname
env locale
getnetbyaddr() Thread safetyMT-Unsafe race:netbyaddr
locale
setnetent(),
endnetent()
Thread safetyMT-Unsafe race:netent env
locale

In the above table, netentin race:netentsignifies that if any of the functions setnetent(3), getnetent(3), or endnetent(3) are used in parallel in different threads of a program, then data races could occur.  

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, 4.3BSD.  

NOTES

In glibc versions before 2.2, the netargument of getnetbyaddr() was of type long.  

SEE ALSO

getnetent_r(3), getprotoent(3), getservent(3)
RFC 1101


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
FILES
ATTRIBUTES
CONFORMING TO
NOTES
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 22:27:53 GMT, June 20, 2016