HP-UX Reference (11i v1 05/09) - 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 character
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 signal
is sent to all processes in the foreground process group for which the terminal is the con-
trolling 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 process 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 disappearing
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 discarded when
processed. If IXON is not enabled, the STOP character is treated as a normal data char-
acter. 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 approach-
ing 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 charac-
ter. If IXOFF (input control) is enabled, the system sends a START
character to the ter-
minal 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 (Ctrl-W) and LNEXT (Ctrl-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 the stty
command. The NL and CR characters cannot be changed or disabled. The character values for the
HP-UX 11i Version 1: September 2005 − 5 − Hewlett-Packard Company Section 7−−179