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