BloombergLP::bdls::FilesystemUtil::seek

Synopsis

Declared in <bdls_filesystemutil.h>

static
Offset
seek(
    FileDescriptor descriptor,
    Offset offset,
    int whence);

Description

Set the file pointer associated with the specified descriptor (used by calls to the read and write system calls) according to the specified whence behavior: ` * If 'whence' is e_SEEK_FROM_BEGINNING, set the pointer to 'offset' bytes from the beginning of the file. * If 'whence' is e_SEEK_FROM_CURRENT, advance the pointer by 'offset' bytes * If 'whence' is e_SEEK_FROM_END, set the pointer to 'offset' bytes beyond the end of the file. ` Return the new location of the file pointer, in bytes from the beginning of the file, on success; and -1 otherwise. The effect on the file pointer is undefined unless the file is on a device capable of seeking. Note that seek does not change the size of the file if the pointer advances beyond the end of the file; instead, the next write at the pointer will increase the file size.

Return Value

the new file-pointer location on success, and -1 otherwise

Parameters

Name	Description
descriptor	file descriptor whose file pointer is set
offset	byte offset applied according to `whence`
whence	starting point for the seek operation