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TCSBRK(2const) TCSBRK(2const)

NAME

TCSBRK, TCSBRKP, TIOCSBRK, TIOCCBRK - sending a break

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

#include <asm/termbits.h>  /* Definition of T*BRK* constants */
#include <sys/ioctl.h>
int ioctl(int fd, TCSBRK, int arg);
int ioctl(int fd, TCSBRKP, int arg);
int ioctl(int fd, TIOCSBRK);
int ioctl(int fd, TIOCCBRK);

DESCRIPTION

Equivalent to tcsendbreak(fd, arg).
If the terminal is using asynchronous serial data transmission, and arg is zero, then send a break (a stream of zero bits) for between 0.25 and 0.5 seconds. If the terminal is not using asynchronous serial data transmission, then either a break is sent, or the function returns without doing anything. When arg is nonzero, nobody knows what will happen.
(SVr4, UnixWare, Solaris, and Linux treat tcsendbreak(fd,arg) with nonzero arg like tcdrain(fd). SunOS treats arg as a multiplier, and sends a stream of bits arg times as long as done for zero arg. DG/UX and AIX treat arg (when nonzero) as a time interval measured in milliseconds. HP-UX ignores arg.)
So-called "POSIX version" of TCSBRK. It treats nonzero arg as a time interval measured in deciseconds, and does nothing when the driver does not support breaks.
Turn break on, that is, start sending zero bits.
Turn break off, that is, stop sending zero bits.

RETURN VALUE

On success, 0 is returned. On error, -1 is returned, and errno is set to indicate the error.

SEE ALSO

ioctl(2), ioctl_tty(2)

2024-06-13 Linux man-pages (unreleased)