установить текущую позицию файла (set current file position)
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)
fsetpos — set current file position
Синопсис (Synopsis)
#include <stdio.h>
int fsetpos(FILE *stream, const fpos_t *pos);
Описание (Description)
The functionality described on this reference page is aligned
with the ISO C standard. Any conflict between the requirements
described here and the ISO C standard is unintentional. This
volume of POSIX.1‐2017 defers to the ISO C standard.
The fsetpos() function shall set the file position and state
indicators for the stream pointed to by stream according to the
value of the object pointed to by pos, which the application
shall ensure is a value obtained from an earlier call to
fgetpos() on the same stream. If a read or write error occurs,
the error indicator for the stream shall be set and fsetpos()
fails.
A successful call to the fsetpos() function shall clear the end-
of-file indicator for the stream and undo any effects of ungetc()
on the same stream. After an fsetpos() call, the next operation
on an update stream may be either input or output.
The behavior of fsetpos() on devices which are incapable of
seeking is implementation-defined. The value of the file offset
associated with such a device is undefined.
The fsetpos() function shall not change the setting of errno if
successful.
Возвращаемое значение (Return value)
The fsetpos() function shall return 0 if it succeeds; otherwise,
it shall return a non-zero value and set errno to indicate the
error.
Ошибки (Error)
The fsetpos() function shall fail if, either the stream is
unbuffered or the stream's buffer needed to be flushed, and the
call to fsetpos() causes an underlying lseek() or write() to be
invoked, and:
EAGAIN The O_NONBLOCK flag is set for the file descriptor and the
thread would be delayed in the write operation.
EBADF The file descriptor underlying the stream file is not open
for writing or the stream's buffer needed to be flushed
and the file is not open.
EFBIG An attempt was made to write a file that exceeds the
maximum file size.
EFBIG An attempt was made to write a file that exceeds the file
size limit of the process.
EFBIG The file is a regular file and an attempt was made to
write at or beyond the offset maximum associated with the
corresponding stream.
EINTR The write operation was terminated due to the receipt of a
signal, and no data was transferred.
EIO A physical I/O error has occurred, or the process is a
member of a background process group attempting to perform
a write() to its controlling terminal, TOSTOP is set, the
calling thread is not blocking SIGTTOU, the process is not
ignoring SIGTTOU, and the process group of the process is
orphaned. This error may also be returned under
implementation-defined conditions.
ENOSPC There was no free space remaining on the device containing
the file.
EPIPE An attempt was made to write to a pipe or FIFO that is not
open for reading by any process; a SIGPIPE signal shall
also be sent to the thread.
ESPIPE The file descriptor underlying stream is associated with a
pipe, FIFO, or socket.
The fsetpos() function may fail if:
ENXIO A request was made of a nonexistent device, or the request
was outside the capabilities of the device.
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)
Section 2.5, Standard I/O Streams, fopen(3p), ftell(3p),
lseek(3p), rewind(3p), ungetc(3p), write(3p)
The Base Definitions volume of POSIX.1‐2017, stdio.h(0p)
