termios.h(0P)		   POSIX Programmer's Manual		 termios.h(0P)

PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the corresponding
       Linux manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.

NAME
       termios.h — define values for termios

SYNOPSIS
       #include <termios.h>

DESCRIPTION
       The <termios.h> header shall contain the definitions used by the
       terminal I/O interfaces (see Chapter 11, General Terminal Interface for
       the structures and names defined).

   The termios Structure
       The <termios.h> header shall define the following data types through
       typedef:

       cc_t	   Used for terminal special characters.

       speed_t	   Used for terminal baud rates.

       tcflag_t	   Used for terminal modes.

       The above types shall be all unsigned integer types.

       The implementation shall support one or more programming environments
       in which the widths of cc_t, speed_t, and tcflag_t are no greater than
       the width of type long.	The names of these programming environments
       can be obtained using the confstr() function or the getconf utility.

       The <termios.h> header shall define the termios structure, which shall
       include at least the following members:


	   tcflag_t  c_iflag	 Input modes.
	   tcflag_t  c_oflag	 Output modes.
	   tcflag_t  c_cflag	 Control modes.
	   tcflag_t  c_lflag	 Local modes.
	   cc_t	     c_cc[NCCS]	 Control characters.

       The <termios.h> header shall define the following symbolic constant:

       NCCS	   Size of the array c_cc for control characters.

       The <termios.h> header shall define the following symbolic constants
       for use as subscripts for the array c_cc:

	      ┌────────────────────────────────────┬──────────────────┐
	      │		 Subscript Usage	   │		      │
	      │Canonical Mode ╷ Non-Canonical Mode │   Description    │
	      ├───────────────┬────────────────────┼──────────────────┤
	      │VEOF	      │			   │ EOF character.   │
	      │VEOL	      │			   │ EOL character.   │
	      │VERASE	      │			   │ ERASE character. │
	      │VINTR	      │ VINTR		   │ INTR character.  │
	      │VKILL	      │			   │ KILL character.  │
	      │		      │ VMIN		   │ MIN value.	      │
	      │VQUIT	      │ VQUIT		   │ QUIT character.  │
	      │VSTART	      │ VSTART		   │ START character. │
	      │VSTOP	      │ VSTOP		   │ STOP character.  │
	      │VSUSP	      │ VSUSP		   │ SUSP character.  │
	      │		      │ VTIME		   │ TIME value.      │
	      └───────────────┴────────────────────┴──────────────────┘
       The subscript values shall be suitable for use in #if preprocessing
       directives and shall be distinct, except that the VMIN and VTIME
       subscripts may have the same values as the VEOF and VEOL subscripts,
       respectively.

   Input Modes
       The <termios.h> header shall define the following symbolic constants
       for use as flags in the c_iflag field. The c_iflag field describes the
       basic terminal input control.

       BRKINT	   Signal interrupt on break.

       ICRNL	   Map CR to NL on input.

       IGNBRK	   Ignore break condition.

       IGNCR	   Ignore CR.

       IGNPAR	   Ignore characters with parity errors.

       INLCR	   Map NL to CR on input.

       INPCK	   Enable input parity check.

       ISTRIP	   Strip character.

       IXANY	   Enable any character to restart output.

       IXOFF	   Enable start/stop input control.

       IXON	   Enable start/stop output control.

       PARMRK	   Mark parity errors.

   Output Modes
       The <termios.h> header shall define the following symbolic constants
       for use as flags in the c_oflag field. The c_oflag field specifies the
       system treatment of output.

       OPOST	   Post-process output.

       ONLCR	   Map NL to CR-NL on output.

       OCRNL	   Map CR to NL on output.

       ONOCR	   No CR output at column 0.

       ONLRET	   NL performs CR function.

       OFDEL	   Fill is DEL.

       OFILL	   Use fill characters for delay.

       NLDLY	   Select newline delays:

		   NL0	   Newline type 0.

		   NL1	   Newline type 1.

       CRDLY	   Select carriage-return delays:

		   CR0	   Carriage-return delay type 0.

		   CR1	   Carriage-return delay type 1.

		   CR2	   Carriage-return delay type 2.

		   CR3	   Carriage-return delay type 3.

       TABDLY	   Select horizontal-tab delays:

		   TAB0	   Horizontal-tab delay type 0.

		   TAB1	   Horizontal-tab delay type 1.

		   TAB2	   Horizontal-tab delay type 2.

		   TAB3	   Expand tabs to spaces.

       BSDLY	   Select backspace delays:

		   BS0	   Backspace-delay type 0.

		   BS1	   Backspace-delay type 1.

       VTDLY	   Select vertical-tab delays:

		   VT0	   Vertical-tab delay type 0.

		   VT1	   Vertical-tab delay type 1.

       FFDLY	   Select form-feed delays:

		   FF0	   Form-feed delay type 0.

		   FF1	   Form-feed delay type 1.

   Baud Rate Selection
       The <termios.h> header shall define the following symbolic constants
       for use as values of objects of type speed_t.

       The input and output baud rates are stored in the termios structure.
       These are the valid values for objects of type speed_t.	Not all baud
       rates need be supported by the underlying hardware.

       B0	   Hang up

       B50	   50 baud

       B75	   75 baud

       B110	   110 baud

       B134	   134.5 baud

       B150	   150 baud

       B200	   200 baud

       B300	   300 baud

       B600	   600 baud

       B1200	   1200 baud

       B1800	   1800 baud

       B2400	   2400 baud

       B4800	   4800 baud

       B9600	   9600 baud

       B19200	   19200 baud

       B38400	   38400 baud

   Control Modes
       The <termios.h> header shall define the following symbolic constants
       for use as flags in the c_cflag field. The c_cflag field describes the
       hardware control of the terminal; not all values specified are required
       to be supported by the underlying hardware.

       CSIZE	   Character size:

		   CS5	   5 bits

		   CS6	   6 bits

		   CS7	   7 bits

		   CS8	   8 bits

       CSTOPB	   Send two stop bits, else one.

       CREAD	   Enable receiver.

       PARENB	   Parity enable.

       PARODD	   Odd parity, else even.

       HUPCL	   Hang up on last close.

       CLOCAL	   Ignore modem status lines.

       The implementation shall support the functionality associated with the
       symbols CS7, CS8, CSTOPB, PARODD, and PARENB.

   Local Modes
       The <termios.h> header shall define the following symbolic constants
       for use as flags in the c_lflag field. The c_lflag field of the
       argument structure is used to control various terminal functions.

       ECHO	   Enable echo.

       ECHOE	   Echo erase character as error-correcting backspace.

       ECHOK	   Echo KILL.

       ECHONL	   Echo NL.

       ICANON	   Canonical input (erase and kill processing).

       IEXTEN	   Enable extended input character processing.

       ISIG	   Enable signals.

       NOFLSH	   Disable flush after interrupt or quit.

       TOSTOP	   Send SIGTTOU for background output.

   Attribute Selection
       The <termios.h> header shall define the following symbolic constants
       for use with tcsetattr():

       TCSANOW	   Change attributes immediately.

       TCSADRAIN   Change attributes when output has drained.

       TCSAFLUSH   Change attributes when output has drained; also flush
		   pending input.

   Line Control
       The <termios.h> header shall define the following symbolic constants
       for use with tcflush():

       TCIFLUSH	   Flush pending input.

       TCIOFLUSH   Flush both pending input and untransmitted output.

       TCOFLUSH	   Flush untransmitted output.

       The <termios.h> header shall define the following symbolic constants
       for use with tcflow():

       TCIOFF	   Transmit a STOP character, intended to suspend input data.

       TCION	   Transmit a START character, intended to restart input data.

       TCOOFF	   Suspend output.

       TCOON	   Restart output.

       The <termios.h> header shall define the pid_t type as described in
       <sys/types.h>.

       The following shall be declared as functions and may also be defined as
       macros. Function prototypes shall be provided.


	   speed_t cfgetispeed(const struct termios *);
	   speed_t cfgetospeed(const struct termios *);
	   int	   cfsetispeed(struct termios *, speed_t);
	   int	   cfsetospeed(struct termios *, speed_t);
	   int	   tcdrain(int);
	   int	   tcflow(int, int);
	   int	   tcflush(int, int);
	   int	   tcgetattr(int, struct termios *);
	   pid_t   tcgetsid(int);
	   int	   tcsendbreak(int, int);
	   int	   tcsetattr(int, int, const struct termios *);

       The following sections are informative.

APPLICATION USAGE
       The following names are reserved for XSI-conformant systems to use as
       an extension to the above; therefore strictly conforming applications
       shall not use them:

       CBAUD	  EXTB	     VDSUSP
       DEFECHO	  FLUSHO     VLNEXT
       ECHOCTL	  LOBLK	     VREPRINT
       ECHOKE	  PENDIN     VSTATUS
       ECHOPRT	  SWTCH	     VWERASE
       EXTA	  VDISCARD

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       <sys_types.h>

       The System Interfaces volume of POSIX.1‐2017, cfgetispeed(),
       cfgetospeed(), cfsetispeed(), cfsetospeed(), confstr(), tcdrain(),
       tcflow(), tcflush(), tcgetattr(), tcgetsid(), tcsendbreak(),
       tcsetattr()

       The Shell and Utilities volume of POSIX.1‐2017, Chapter 11, General
       Terminal Interface, getconf

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group		     2017			 termios.h(0P)