Ioctl requests Request codes are often device-specific. Macros and defines used in specifying an ioctl () request are located in the file <sys/ioctl. The ioctl cmd code specifies the request function to be called. terminals) may be controlled with ioctl() requests. . It has encoded in it whether the argument is an input, output or read/write In computing, ioctl (an abbreviation of input/output control) is a system call for device-specific input/output operations and other operations which cannot be expressed by regular file semantics. h>. The ioctl () function manipulates the underlying device parameters of special files. g. RETURN VALUE Usually, on success zero is returned. It is flexible and easily extended by adding new commands and can be passed through character devices, block devices as well as sockets and other special file descriptors. The ioctl() function manipulates the underlying device parameters of special files. , terminals) may be controlled with ioctl() requests. The third argument is The ioctl () function manipulates request parameters. It takes a parameter specifying a request code; the effect of a call depends completely on the request code. The second argument is a device-dependent request code. , terminals) may be controlled with ioctl () operations. h> . In particular, many operating characteristics of character special files (e. #include <sys/ioctl. h> int ioctl(int fd, unsigned long request, ); DESCRIPTION The ioctl() system call manipulates the underlying device parameters of special files. Macros and defines used in specifying an ioctl() request are located in the file <sys/ioctl. In particular, many operating characteristics of character special files (e. The second argument is a device-dependent operation code. The argument fd must be an open file descriptor. An ioctl() request has encoded in it whether the argument is an in parameter or out parameter, and the size of the argument argp in bytes. The argument d must be an open file descriptor. , terminals) may be controlled with ioctl () requests. A few ioctl() requests use the return value as an output parameter and return a nonnegative value on success. ioctl () is the most common way for applications to interface with device drivers. dsdgx jutw lhcbqv mehh nxajm jst dltc mver psgosdi leh