PHP Manual: Allows the caller to directly manipulate the allocated disk space for a file

Description

resource eio_fallocate(
    mixed $fd,
    int $mode,
    int $offset,
    int $length,
    int $pri = EIO_PRI_DEFAULT,
    callable $callback = NULL,
    mixed $data = NULL
)

eio_fallocate allows the caller to directly manipulate the allocated disk space for the file specified by fd file descriptor for the byte range starting at offset and continuing for length bytes.

Note: File should be opened for writing

EIO_O_CREAT should be logically OR'd with EIO_O_WRONLY, or EIO_O_RDWR

Parameters

fd

Stream, Socket resource, or numeric file descriptor, e.g. returned by eio_open.

mode

Currently only one flag is supported for mode: EIO_FALLOC_FL_KEEP_SIZE (the same as POSIX constant FALLOC_FL_KEEP_SIZE).

offset

Specifies start of the byte range.

length

Specifies length the byte range.

pri

The request priority: EIO_PRI_DEFAULT, EIO_PRI_MIN, EIO_PRI_MAX, or null. If null passed, pri internally is set to EIO_PRI_DEFAULT.

callback

callback function is called when the request is done. It should match the following prototype:

void callback(mixed $data, int $result[, resource $req]);

data: is custom data passed to the request.
result: request-specific result value; basically, the value returned by corresponding system call.
req: is optional request resource which can be used with functions like eio_get_last_error.

data

Arbitrary variable passed to callback.

Return Values

eio_fallocate returns request resource on success, or false on failure.