Mar 04, 2012 I'm trying to understand the termio.h header file. However, all information I find is quite old and everything seems to happen in C code instead of C. Is there any modern way to communicate with a serial link? The termio.h ccflag field also specifies CBAUD to a maximum of 38400, which would be too low for my program. C standard library header files.; 2 minutes to read +1; In this article. Header files for the C standard library and extensions, by category. Headers by category. 11 Added in the C11 standard. 14 Added in the C14 standard. 17 Added in the C17 standard. 20 Added in the draft C20 standard.
Name
tty_ioctl - ioctls for terminals and serial lines
Synopsis
#include <termios.h>
int ioctl(intfd, intcmd, ..);
Description
The ioctl(2) call for terminals and serial ports accepts many possible command arguments. Most require a third argument, of varying type, here calledargp or arg.
Use of ioctl makes for nonportable programs. Use the POSIX interface described in termios(3) whenever possible.
Get and set terminal attributes
TCGETS
- TCSETS
Set the current serial port settings.
- TCSETSF
Allow the output buffer to drain, discard pending input, and set the current serial port settings.
TCGETA
- const struct termio *argp
Locking the termios structure
- Termios H Dev C Online
- TIOCSWINSZ
- Set window size.
- The struct used by these ioctls is defined as
- When the window size changes, a SIGWINCH signal is sent to the foreground process group.
- intarg Equivalent to tcsendbreak(fd, arg).
- TIOCCBRK
- void
- Turn break off, that is, stop sending zero bits.
- int *argp
- Get the number of bytes in the input buffer.
- TIOCOUTQ
- int *argp
- Get the number of bytes in the output buffer.
- const char *argp
- Insert the given byte in the input queue.
- intarg
- Make the given terminal the controlling terminal of the calling process. The calling process must be a session leader and not have a controlling terminalalready. If this terminal is already the controlling terminal of a different session group then the ioctl fails with EPERM, unless the caller is root(more precisely: has the CAP_SYS_ADMIN capability) and arg equals 1, in which case the terminal is stolen, and all processes that had it ascontrolling terminal lose it.
- pid_t *argp
- When successful, equivalent to *argp = tcgetpgrp(fd).
Get the process group ID of the foreground process group on this terminal. - TIOCGSID
- pid_t *argp
- Get the session ID of the given terminal. This will fail with ENOTTY in case the terminal is not a master pseudoterminal and not our controllingterminal. Strange.
- TIOCNXCL
- void
- Disable exclusive mode.
- TIOCSETD
- const int *argp
- Set the line discipline of the terminal.
- const int *argp Enable (when *argp is nonzero) or disable packet mode. Can be applied to the master side of a pseudoterminal only (and will return ENOTTYotherwise). In packet mode, each subsequent read(2) will return a packet that either contains a single nonzero control byte, or has a single bytecontaining zero (' ') followed by data written on the slave side of the pseudoterminal. If the first byte is not TIOCPKT_DATA (0), it is an OR of one ormore of the following bits:While this mode is in use, the presence of control status information to be read from the master side may be detected by a select(2) for exceptionalconditions.
- TIOCMSET
- const int *argp
- set the status of modem bits.
- TIOCMBIS
- const int *argp
- set the indicated modem bits.
- Bits used by these four ioctls:
const struct winsize *argp
Sending a break
TCSBRK
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 0.5seconds. If the terminal is not using asynchronous serial data transmission, then either a break is sent, or the function returns without doing anything. Whenarg is nonzero, nobody knows what will happen.
(SVr4, UnixWare, Solaris, 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 inmilliseconds. HP-UX ignores arg.) Auto tune preset ableton.
Software flow control
TCXONC
Redirecting console output
TIOCCONS
Exclusive mode
TIOCEXCL
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Line discipline
TIOCGETD
Pseudoterminal ioctls
TIOCPKT
This mode is used by rlogin(1) and rlogind(8) to implement a remote-echoed, locally ^S/^Q flow-controlled remote login.
The BSD ioctls TIOCSTOP, TIOCSTART, TIOCUCNTL, TIOCREMOTE have not been implemented under Linux.
Modem control Cooking seekhi hanji song download mp3.
TIOCMGET
Marking a line as local
TIOCGSOFTCAR
Linux-specific
- #include <linux/tty.h>
TIOCTTYGSTRUCT
See Also
ioctl(2), termios(3), console_ioctl(4), pty(7)