определения векторных операций ввода/вывода (definitions for vector I/O operations)
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)
sys/uio.h — definitions for vector I/O operations
Синопсис (Synopsis)
#include <sys/uio.h>
Описание (Description)
The <sys/uio.h> header shall define the iovec structure, which
shall include at least the following members:
void *iov_base Base address of a memory region for input or output.
size_t iov_len The size of the memory pointed to by iov_base.
The <sys/uio.h> header uses the iovec structure for
scatter/gather I/O.
The <sys/uio.h> header shall define the ssize_t and size_t types
as described in <sys/types.h>.
The following shall be declared as functions and may also be
defined as macros. Function prototypes shall be provided.
ssize_t readv(int, const struct iovec *, int);
ssize_t writev(int, const struct iovec *, int);
The following sections are informative.
Использование в приложениях (Application usage)
The implementation can put a limit on the number of
scatter/gather elements which can be processed in one call. The
symbol {IOV_MAX} defined in <limits.h> should always be used to
learn about the limits instead of assuming a fixed value.
Обоснование (Rationale)
Traditionally, the maximum number of scatter/gather elements the
system can process in one call were described by the symbolic
value {UIO_MAXIOV}. In IEEE Std 1003.1‐2001 this value is
replaced by the constant {IOV_MAX} which can be found in
<limits.h>.
Будущие направления (Future directions)
None.
Смотри также (See also)
limits.h(0p), sys_types.h(0p)
The System Interfaces volume of POSIX.1‐2017, read(3p),
readv(3p), write(3p), writev(3p)
