Reading from a special device. More...
|fd_t||op_open_device (char const *name)|
|op_open_device - open a special char device for reading |
|ssize_t||op_read_device (fd_t devfd, void *buf, size_t size)|
|op_read_device - read from a special char device |
Reading from a special device.
|fd_t op_open_device||(||char const *||name||)|
op_open_device - open a special char device for reading
|name||file name of device file|
Open the special file name. Returns the file descriptor for the file or -1 on error.
op_read_device - read from a special char device
|devfd||file descriptor of device|
|size||size of buffer|
Read size bytes from a device into buffer buf. A seek to the start of the device file is done first then a read is requested in one go of size bytes.
It is the caller's responsibility to do further op_read_device() calls if the number of bytes read is not what is requested (where this is applicable).
The number of bytes read is returned, or a negative number on failure (in which case errno will be set). If the call is interrupted, then errno will be EINTR, and the client should arrange for re-starting the read if necessary.