Advanced Programming in the UNIX® Environment

ptg10805159

Section 18.5 Te rminal Option Flags 687

ECHOK (c_lflag,POSIX.1, FreeBSD, Linux, Mac OS X, Solaris) If set and if

ICANON is set, the KILL character erases the current line from the

display or outputs the NL character (to emphasize that the entireline

was erased).

If theECHOKEflag is supported, this description ofECHOKassumes that

ECHOKEis not set.

ECHOKE (c_lflag,FreeBSD, Linux, Mac OS X, Solaris) If set and ifICANONis

set, the KILL character is echoed by erasing each character on the line.

The way in which each character is erased is selected by theECHOEand

ECHOPRTflags.

ECHONL (c_lflag,POSIX.1, FreeBSD, Linux, Mac OS X, Solaris) If set and if

ICANONis set, the NL character is echoed, even ifECHOis not set.

ECHOPRT (c_lflag,FreeBSD, Linux, Mac OS X, Solaris) If set and if both

ICANONandECHOareset, then the ERASE character (and WERASE

character, if supported) cause all the characters being erased to be

printed as they areerased. This is often useful on a hard-copy terminal

to see exactly which characters arebeing deleted.

EXTPROC (c_lflag,FreeBSD, Linux, Mac OS X) If set, canonical character

processing is performed external to the operating system. This can be

the case if the serial communication peripheral cardcan offload the host

processor by doing some of the line discipline processing. This can also

be the case when using pseudo terminals (Chapter 19).

FFDLY (c_oflag,XSI, Linux, Solaris) Form feed delay mask. The values for

the mask areFF0orFF1.

FLUSHO (c_lflag,FreeBSD, Linux, Mac OS X, Solaris) If set, output is being

flushed. This flag is set when we type the DISCARD character; the flag

is cleared when we type another DISCARD character.Wecan also set or

clear this condition by setting or clearing this terminal flag.

HUPCL (c_cflag,POSIX.1, FreeBSD, Linux, Mac OS X, Solaris) If set, the

modem control lines arelowered (i.e., the modem connection is broken)

when the last process closes the device.

ICANON (c_lflag,POSIX.1, FreeBSD, Linux, Mac OS X, Solaris) If set, canonical

mode is in effect (Section 18.10). This enables the following characters:

EOF,EOL, EOL2, ERASE, KILL, REPRINT,STATUS, and WERASE. The

input characters areassembled into lines.

If canonical mode is not enabled, read requests aresatisfied directly

from the input queue. Aread does not return until at least MIN bytes

have been received or the timeout value TIME has expired between

bytes. Refer to Section 18.11for additional details.