Read the next line of the host database file
#include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> struct hostent * gethostent_r( FILE ** hostf, struct hostent * result, char * buffer, int buflen, int * h_errnop );
- NULL, or the address of the FILE * pointer associated with the host database file.
- A pointer to a struct hostent where the function can store the host entry.
- A pointer to a buffer that the function can use during the operation to store host database entries; buffer should be large enough to hold all of the data associated with the host entry. A 2K buffer is usually more than enough; a 256-byte buffer is safe in most cases.
- The length of the area pointed to by buffer.
- A pointer to a location where the function can store an herrno value if an error occurs.
Use the -l socket option to qcc to link against this library.
The gethostent_r() function is a thread-safe version of the gethostent() function. This function gets the local host's entry. If the pointer pointed to by hostf is NULL, gethostent_r() opens /etc/hosts and returns its file pointer in hostf for later use. It's the calling process's responsibility to close the host file with fclose().
The first time that you call gethostent_r(), pass NULL in the pointer pointed to by hostf.
A pointer to result, or NULL if an error occurs.
If an error occurs, the int pointed to by h_errnop is set to:
- The supplied buffer isn't large enough to store the result.
- Authoritative answer: Unknown host.
- No address associated with name, look for an MX record.
- 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).
- Unknown server error. An unexpected server failure was encountered. This is a nonrecoverable network error.
- 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.
- Local host database file.
Last modified: 2014-06-24