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herror()

Print the message associated with the value of h_errno to standard error

Synopsis:

#include <netdb.h>

void herror( const char* prefix );

Arguments:

prefix

NULL, or a string that you want to print before the error message.

Library:

libsocket

Use the -l socket option to qcc to link against this library.

Description:

The herror() function prints the message corresponding to the error number contained in h_errno to stderr. The following functions can set h_errno:

• gethostbyaddr()
• gethostbyaddr_r()
• gethostbyname()
• gethostbyname2()
• gethostbyname_r()
• res_query()
• res_search()

If the prefix string is non-NULL, it's printed, followed by a colon and a space. The error message is printed with a trailing newline. One of the following messages could be printed:

HOST_NOT_FOUND

Authoritative answer: Unknown host.

NETDB_INTERNAL

You specified an invalid address family when calling gethostbyname2().

NO_DATA

Valid name, no data record of the requested type. The name is known to the name server, but has no IP address associated with it -- this isn't a temporary error. Another type of request to the name server using this domain name will result in an answer (e.g. a mail-forwarder may be registered for this domain).

NO_RECOVERY

Unknown server error. An unexpected server failure was encountered. This is a nonrecoverable network error.

TRY_AGAIN

Nonauthoritative answer: Host name lookup failure. This is usually a temporary error and means that the local server didn't receive a response from an authoritative server. A retry at some later time may succeed.

Classification:

Unix

Safety:
Cancellation point	Yes
Interrupt handler	No
Signal handler	No
Thread	No

See also:

gethostbyaddr(), gethostbyaddr_r(), gethostbyname(), gethostbyname_r(), h_errno, res_query(), res_search(), stderr

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