NAME

termios.h - define values for termios

SYNOPSIS

#include <termios.h>

DESCRIPTION

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

The termios Structure

The following data types are 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 are all unsigned integral types.

The termios structure is defined, and includes 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 chars

A definition is given for:

NCCS

Size of the array c_cc for control characters.

The following subscript names for the array c_cc are 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 are unique, except that the VMIN and VTIME subscripts may have the same values as the VEOF and VEOL subscripts, respectively.

Input Modes

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

IUCLC

Map upper-case to lower-case on input (LEGACY).

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 c_oflag field specifies the system treatment of output:

OPOST

Post-process output

OLCUC

Map lower-case to upper-case on output (LEGACY).

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 character type 0.

NL1

Newline character 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 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 are 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

Control Modes

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.

Local Modes

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.

XCASE

Canonical upper/lower presentation (LEGACY).

Attribute Selection

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.

Line Control

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

TCIFLUSH

Flush pending input. Flush untransmitted output.

TCIOFLUSH

Flush both pending input and untransmitted output.

The following symbolic constants for use with tcflow() are 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 are declared as functions and may also be defined as macros. Function prototypes must be provided for use with an ISO C compiler.

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, struct termios *);

APPLICATION USAGE

The following names are commonly used as extensions to the above, therefore portable applications must not use them:

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

FUTURE DIRECTIONS

None.

SEE ALSO

cfgetispeed(), cfgetospeed(), cfsetispeed(), cfsetospeed(), tcdrain(), tcflow(), tcflush(), tcgetattr(), tcgetsid(), tcsendbreak(), tcsetattr(), the XBD specification, General Terminal Interface.