HP-UX Reference (11i v1 00/12) - 3 Library Functions A-M (vol 6)

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD

/build/1111/BRICK/man3/!!!intro.3c

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getprotoent(3N) getprotoent(3N)

Name Service Switch-Based Operation

The library routines getprotobyname(), getprotobynumber(), getprotoent(), and their

reentrant counterparts, internally call the name service switch to access the "protocols" 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 protocol names and numbers.

RETURN VALUE

getprotoent(), getprotobyname(), and getprotobynumber() return a null pointer (0) on

EOF or when they are unable to open /etc/protocols.

OBSOLESCENT INTERFACES

int getprotoent_r(struct protoent *result,

struct protoent_data *buffer);

int getprotobyname_r(const char *name,

struct protoent *result,

struct protoent_data *buffer);

int getprotobynumber_r(int proto,

struct protoent *result,

struct protoent_data *buffer);

int setprotoent_r(int stayopen, struct protoent_data *buffer);

int endprotoent_r(struct protoent_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 a future release. New multithreaded applications should use

the regular APIs without _r.

The reentrant interfaces performs the same operation as their regular counterpart (those without the _r

sufﬁx.) However, getprotoent_r()

, getprotobyname_r(), and getprotobyport_r()

expect to be passed the address of a struct protoent parameter and will store the address of the

result at this supplied parameter. An additional parameter, an address to struct protoent_data, which is

deﬁned in the ﬁle

<netdb.h> cannot be a NULL pointer.

The reentrant routines return -1 if the operation is unsuccessful, or, in the case of

getprotoent_r(),

if the end of the services list has been reached.

0 is returned otherwise.

EXAMPLES

The following code excerpt counts the number of protocols entries:

int count = 0;

(void) setprotoent(0);

while (getprotoent() != NULL)

count++;

(void) endprotoent();

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

getprotoent() was developed by Sun Microsystems Inc.

FILES

/etc/protocols