HP-UX Reference (11i v3 07/02) - 7 Device (Special) Files, 9 General Information, Index (vol 10)

t
termio(7) termio(7)
character is treated as a normal data character.
NL (ASCII LF) special character on input and is recognized if
ICANON flag is enabled. It is
the line delimiter (
\n). If ICANON
is not enabled, the NL character is treated as a nor-
mal data character.
EOL (ASCII NUL) special character on input and is recognized if
ICANON is enabled. EOL
is an additional line delimiter similar to NL. It is not normally used. If
ICANON is not
enabled, the EOL character is treated as a normal data character.
EOL2 (disabled) special character on input and is recognized if
ICANON is enabled. EOL2 is
an additional line delimiter similar to EOL. It is not normally used. If
ICANON is not
enabled, the EOL2 character is treated as a normal data character.
SUSP (disabled) special character recognized on input. If
ISIG is enabled, receipt of the
SUSP character causes a
SIGTSTP signal to be sent to all processes in the foreground
process group for which the terminal is the controlling terminal, and the SUSP charac-
ter is discarded when processed. If ISIG is not enabled, the SUSP character is treated
as a normal data character. Command interpreter processes typically set SUSP to
Control-Z.
DSUSP (disabled) special character recognized on input. If
ISIG is enabled, and a process in
the foreground process group attempts to read the DSUSP character, a SIGTSTP sig-
nal is sent to all processes in the foreground process group for which the terminal is the
controlling terminal, and the DSUSP character is then discarded. If ISIG is not
enabled, the DSUSP character is treated as a normal data character. Note that DSUSP
is similar to SUSP except that the signal is sent when a process in the foreground pro-
cess group attempts to read the DSUSP character, rather than when it is typed.
STOP (Control-S or ASCII DC3) special character on both input and output. If IXON (output
control) is enabled, processing of the STOP character temporarily suspends output to
the terminal device. This is useful with CRT terminals to prevent output from disap-
pearing before it can be read. While output is suspended and
IXON is enabled, STOP
characters are ignored and not read. If IXON is enabled, the STOP character is dis-
carded when processed. If IXON is not enabled, the STOP character is treated as a
normal data character. If IXOFF (input control) is enabled, the system sends a STOP
character to the terminal device when the number of unread characters in the input
queue is approaching a system specified limit. This is an attempt to prevent this buffer
from overflowing by telling the terminal device to stop sending data.
START (Control-Q or ASCII DC1) special character on both input and output. If
IXON (output
control) is enabled, processing of the START character resumes output that has been
suspended. While output is not suspended and
IXON is enabled, START characters are
ignored and not read. If IXON is enabled, the START character is discarded when pro-
cessed. If IXON is not enabled, the START character is treated as a normal data char-
acter. If IXOFF (input control) is enabled, the system sends a START character to the
terminal device when the input queue has drained to a certain system-defined level.
This occurs when the input queue is no longer in danger of possibly overflowing.
CR (ASCII CR) special character on input is recognized if ICANON is enabled. When
ICANON and ICRNL are enabled and IGNCR is not enabled, this character is
translated into a NL, and has the same affect as the NL character. If ICANON and
IGNCR are enabled, the CR character is ignored. If ICANON is enabled and both
ICRNL and IGNCR are not enabled, the CR character is treated as a normal data char-
acter.
LNEXT (disabled) special character recognized on input. Causes the special meaning of the next
character to be ignored. This works for all special characters specified above. It allows
characters to be input that would otherwise be interpreted by the system for a special
function.
The special characters are assigned their default character values when the terminal port is opened. The
default values used are those specified by the System V Interface Definition, Third Edition (SVID3), except
for the WERASE (Control-W) and LNEXT (Control-V) characters which are set to _POSIX_VDISABLE to
maintain binary compatibility with previous releases of HP-UX. The default character values assigned
when the port is opened can be changed for all ports on a system wide basis through the use of the stty
command (see stty(1)). The character values may also be changed for a specific port after it is opened using
HP-UX 11i Version 3: February 2007 − 5 − Hewlett-Packard Company 213