DCMD_CHR_ISCHARS

Determine the number of characters waiting to be read

Synopsis:

#include <sys/dcmd_chr.h>

#define DCMD_CHR_ISCHARS    __DIOF('f', 127, unsigned)   /* FIONREAD */

Argument	Value
`filedes`	A file descriptor that you obtained by opening the device.
`dcmd`	DCMD_CHR_ISCHARS
`dev_data_ptr`	A pointer to an unsigned
`n_bytes`	`sizeof(unsigned)`
`dev_info_ptr`	NULL

This command determine the number of characters waiting to be read. It's also implemented as the FIONREAD ioctl() command.

Note: This command is for internal use, and you shouldn't use it directly. Instead use the tcischars() cover function.

None.

The number of characters.