ioctl

• The ioctl system call is an all-purpose interface for controlling hardware devices.
  • The first argument to ioctl is a file descriptor, which should be opened to the device that you want to control.
  • The second argument is a request code that indicates the operation that you want to perform.
• The http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/cdrom-eject.cprogram in Fig. 7 presents a short program that ejects the disk in a CD-ROM drive (if the drive supports this).

  Figure 7: Eject a CD-ROM.

  

  $ ./cdrom-eject /dev/hdc