GETHOSTENT(3) Library Functions Manual GETHOSTENT(3)

endhostent gethostent sethostent — network host database functions

#include <netdb.h>

void endhostent(void);
struct hostent *gethostent(void);
void sethostent(int stayopen);

These functions shall retrieve information about hosts. This information is considered to be stored in a database that can be accessed sequentially or randomly. The implementation of this database is unspecified.

In many cases this database is implemented by the Domain Name System, as documented in RFC 1034, RFC 1035, and RFC 1886.

The sethostent () function shall open a connection to the database and set the next entry for retrieval to the first entry in the database. If the argument is non-zero, the connection shall not be closed by a call to gethostent (), gethostbyname(3), or gethostbyaddr(3), and the implementation may maintain an open file descriptor.

The gethostent () function shall read the next entry in the database, opening and closing a connection to the database as necessary.

Entries shall be returned in hostent structures. Refer to gethostbyaddr(3) for a definition of the hostent structure.

The endhostent () function shall close the connection to the database, releasing any open file descriptor.

These functions need not be reentrant. A function that is not required to be reentrant is not required to be thread-safe.

Upon successful completion, the gethostent () function shall return a pointer to a hostent structure if the requested entry was found, and a null pointer if the end of the database was reached or the requested entry was not found.

No errors are defined for endhostent (), gethostent (), and sethostent ().

None.

The gethostent () function may return pointers to static data, which may be overwritten by subsequent calls to any of these functions.

None.

None.

endservent(3), gethostbyaddr(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <netdb.h>

First released in Issue 6. Derived from the XNS, Issue 5.2 specification.

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January 1, 2004 posix.fail