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Manual Reference Pages  - <termios.h> (P)

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termios.h - define values for termios

CONTENTS

Synopsis
Description
     The termios Structure
     Input Modes
     Output Modes
     Baud Rate Selection
     Control Modes
     Local Modes
     Attribute Selection
     Line Control
Application Usage
Rationale
Future Directions
See Also
Copyright

#include <termios.h>

The <termios.h> header contains the definitions used by the terminal I/O interfaces (see General Terminal Interface for the structures and names defined).

The following data types shall be defined 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 structure shall be defined, and 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. 

A definition shall be provided for:

NCCS	Size of the array c_cc for control characters.

The following subscript names for the array c_cc shall be defined:

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 unique, except that the VMIN and VTIME subscripts may have the same values as the VEOF and VEOL subscripts, respectively.

The following flags shall be provided.

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.

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.
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.

The input and output baud rates are stored in the termios structure. These are the valid values for objects of type speed_t. The following values shall be defined, but 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

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.

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.

The following symbolic constants for use with tcsetattr() are defined:

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

The following symbolic constants for use with tcflush() shall be defined:

TCIFLUSH
	Flush pending input.
TCIOFLUSH
	Flush both pending input and untransmitted output.
TCOFLUSH
	Flush untransmitted output.
The following symbolic constants for use with tcflow() shall be defined:
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 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.

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

None.

None.

The System Interfaces volume of IEEE Std 1003.1-2001, cfgetispeed(), cfgetospeed(), cfsetispeed(), cfsetospeed(), confstr(), tcdrain(), tcflow(), tcflush(), tcgetattr(), tcgetsid(), tcsendbreak(), tcsetattr(), the Shell and Utilities volume of IEEE Std 1003.1-2001, getconf, General Terminal Interface

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .