herror()

Updated: April 19, 2023

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:

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