Understanding Unix/linux programming-files, devices, and streams

Each device file supports system invoke IOCTL:

• Goal: Control a device
• Header files: #include <sys/ioctl.h>
• Function prototype: int result = IOCTL (int fd, int operation [, Arg ...]);
• Parameters
  • FD: File descriptor associated with file
  • Operation: Type of operation
  • ARG: Optional parameter
  • Result:-1 is wrong; 0 is correct;

In fact, the source or destination of any data is treated by UNIX as a file, and basic system calls support both disk files and device files. Their differences are reflected in the operation of the connection . The file descriptor of the disk file contains the definition code for the buffered and extended properties, and the terminal's file descriptor contains the definition code for edit, Echo, character conversion, and other operations.

Yes, you can. Each process step is considered a property of a connection, or a connection can be considered a combination of processing steps.

An important feature of the underlying data flow model is the modularity of the processing, which can be designed to install a module that converts numbers to Roman numerals if it is not satisfied with only supporting terminal drivers such as the case conversion.

In addition, Unix/linux programming practice looked at about 150 pages, although just follow the book to write the existing code, not to do more practice, but still feel that the understanding of the system deepened a lot ah, after the book to Ken operating system, ha ha, do not know the order has been reversed.

Understanding Unix/linux programming-files, devices, and streams