функции базы данных сетевого хоста (network host database functions)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
endhostent, gethostent, sethostent — network host database
functions
Синопсис (Synopsis)
#include <netdb.h>
void endhostent(void);
struct hostent *gethostent(void);
void sethostent(int stayopen);
Описание (Description)
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.
Note: 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 stayopen argument is non-zero, the connection
shall not be closed by a call to gethostent(), 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.
The endhostent() function shall close the connection to the
database, releasing any open file descriptor.
These functions need not be thread-safe.
Возвращаемое значение (Return value)
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.
The application shall not modify the structure to which the
return value points, nor any storage areas pointed to by pointers
within the structure. The returned pointer, and pointers within
the structure, might be invalidated or the structure or the
storage areas might be overwritten by a subsequent call to
gethostent(). The returned pointer, and pointers within the
structure, might also be invalidated if the calling thread is
terminated.
Ошибки (Error)
No errors are defined for endhostent(), gethostent(), and
sethostent().
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
endservent(3p)
The Base Definitions volume of POSIX.1‐2017, netdb.h(0p)
