Проект OpenNet: MAN posix_fallocate (3) Библиотечные вызовы (FreeBSD и Linux)

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posix_fallocate (3)

>> posix_fallocate (3) ( Solaris man: Библиотечные вызовы )

posix_fallocate (3) ( Linux man: Библиотечные вызовы )

posix_fallocate (3) ( POSIX man: Библиотечные вызовы )

NAME

posix_fallocate - file space control

SYNOPSIS

#include <fcntl.h>

int posix_fallocate(int fd, off_t offset, off_t len);

DESCRIPTION

The posix_fallocate() function ensures that any required storage for regular file data starting at offset and continuing for len bytes is allocated on the file system storage media. If posix_fallocate() returns successfully, subsequent writes to the specified file data will not fail due to the lack of free space on the file system storage media.

If the offset+len is beyond the current file size, then posix_fallocate() adjusts the file size to offset+len. Otherwise, the file size is not changed.

Space allocated with posix_fallocate() is freed by a successful call to creat(2) or open(2) that truncates the size of the file. Space allocated with posix_fallocate() may be freed by a successful call to ftruncate(3C) that reduces the file size to a size smaller than offset+len.

RETURN VALUES

Upon successful completion, posix_fallocate() returns zero. Otherwise, an error number is returned to indicate the error.

ERRORS

The posix_fallocate() function will fail if:

EBADF

: The fd argument is not a valid file descriptor or references a file that was opened without write permission.

EFBIG

: The value of offset+len is greater than the maximum file size.

EINTR

: A signal was caught during execution.

EINVAL

: The len argument is less than or equal to zero, or the offset argument is less than zero, or the underlying file system does not support this operation.

EIO