HP-UX Reference (11i v2 03/08) - 3 Library Functions A-M (vol 6)

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getnetent(3N) getnetent(3N)

Name Service Switch-Based Operation

The library routines getnetbyname()

, getnetbyaddr()

, and getnetent() internally call the

name service switch to access the "networks" database lookup policy conﬁgured in the

/etc/nsswitch.conf

ﬁle (see nsswitch.conf(4)). The lookup policy deﬁnes the order and the criteria

of the supported name services used to resolve network names and addresses.

RETURN VALUE

getnetent(), getnetbyname()

, and getnetbyaddr()

return a null pointer (0) on EOF or when

they are unable to open

/etc/networks

. getnetbyaddr()

also returns a null pointer if its type

parameter is invalid.

EXAMPLE

The following code excerpt counts the number of network entries:

int count = 0;

(void) setnetent(0);

while (netbuf=getnetent() != NULL)

count++;

(void) endnetent();

OBSOLESCENT INTERFACES

int getnetent_r(struct netent *result, struct netent_data *buffer);

int getnetbyname_r(

const char *name,

struct netent *result,

struct netent_data *buffer);

int getnetbyaddr_r(

int net,

int type,

struct netent *result,

struct netent_data *buffer);

int setnetent_r(int stayopen, struct netent_data *buffer);

int endnetent_r(struct netent_data *buffer);

The above reentrant interfaces have been moved from libc to libd4r. They are included to support

existing applications and may be removed in the future release. New multithreaded applications should

not use these APIs.

The reentrant interfaces function the same as the regular interfaces (those without the

-r sufﬁx.) How-

ever, getnetent_r(), getnetbyname_r()

, and getnetbyaddr_r() expect to be passed the

address of a struct netent and will store the address of the result at the supplied parameter. An addi-

tional parameter, the address of struct netent_data , which is deﬁned in the ﬁle

<netdb.h>, cannot be a

NULL pointer.

getnetent_r(), getnetbyname_r(), getnetbyaddr_r()

, setnetent_r(), and

endnetent_t() return a −1 if the operation is unsuccessful. A 0 is returned otherwise.

WARNINGS

Programs that use the interfaces described in this manpage cannot be linked statically because the imple-

mentations of these functions employ dynamic loading and linking of shared objects at run time.

AUTHOR

getnetent() was developed by Sun Microsystems Inc.

FILES

/etc/networks