Set the size of a character device
#include <sys/dcmd_chr.h> #define DCMD_CHR_SETSIZE __DIOT(_CMD_IOCTL_TTY, 103, struct winsize) /* TIOCSWINSZ */
| Argument | Value | 
|---|---|
| filedes | A file descriptor that you obtained by opening the device. | 
| dcmd | DCMD_CHR_SETSIZE | 
| dev_data_ptr | A pointer to a struct winsize (see below) | 
| n_bytes | sizeof(struct winsize) | 
| dev_info_ptr | NULL | 
This command sets the size of a character device. It's also implemented as the TIOCSSIZE or TIOCSWINSZ ioctl() command.
The winsize structure is defined in <sys/ioctl.h> as follows:
struct winsize {
        unsigned short  ws_row;
        unsigned short  ws_col; 
        unsigned short  ws_xpixel;
        unsigned short  ws_ypixel; 
};
None.
DCMD_CHR_GETSIZE, TIOCSSIZE or TIOCSWINSZ
devctl(), tcsetsize() in the QNX Neutrino C Library Reference