Control Characters to Avoid In PEEK & SPY Hot-Key Sequences
Different control characters have special functions on a standard
VT-series terminal. Some of these should not be used as part of
hot-key sequences for PEEK & SPY.
The following table lists control characters which have a special
meaning to VMS. If any of these characters are used by PEEK & SPY,
then you may have trouble activating the corresponding VMS or program
function while using PEEK & SPY. Note that some of these may be used
in the PEEK_DEFAULTS.COM file as supplied on the software distribution.
If they conflict with other key usage on your system you will most
likey want to change the definitions in PEEK_DEFAULTS.COM.
The NULL, XON and XOFF characters will NOT be recognized in
PEEK & SPY hot-key sequences and should not be specified.
Other characters from this list MAY be used, but may create
undesirable effects.
Not Recommended:
Control Character Function
CTRL-@ NULL Ignored by most programs including PEEK & SPY.
(Always ignored in hot-key sequences).
CTRL-A VMS line editing - toggle insert/overtype modes.
CTRL-B VMS line editing - recall prior command line.
CTRL-C Used by VMS to cancel input for most programs.
CTRL-D VMS line editing - move cursor one position to
the left.
CTRL-E VMS line editing - move cursor to end of line.
CTRL-F VMS line editing - move cursor one position to
the right.
CTRL-H BACKSPACE VMS line editing - move cursor to the beginning
of the line.
CTRL-I TAB Horizontal tab character.
CTRL-J LINE-FEED VMS line editing - delete prior word.
CTRL-M RETURN Carriage-return - used to end an input sequence.
CTRL-O Tells VMS to discard terminal output.
CTRL-P Used to halt certain CPUs when entered at the
OPA0 console terminal. (NOTE: If the CPU halts
when CTRL-P is pressed, the CONTINUE command
should be entered at the >>> prompt which is
displayed while the CPU is halted.)
CTRL-Q XON or DC1 Transmit on - for terminal flow control.
(Always ignored in hot-key sequences).
CTRL-R VMS line editing - Re-displays current input.
CTRL-S XOFF or DC3 Transmit off - for terminal flow control.
(Always ignored in hot-key sequences).
CTRL-T Displays a line of statistics if a DCL
$ SET CONTROL=T command was done earlier.
CTRL-U Used by VMS to discard current line of typeahead.
CTRL-V Used by DCL to enable quoting of following
keystroke.
CTRL-X Used by VMS to discard all current typeahead.
CTRL-Y Used by VMS to interrupt program operation.
CTRL-Z Used as an end-of-file or exit command for many
VMS programs.
CTRL-[ ESCAPE Used as part of the sequences generated by any
of the function and keypad keys. Escape may be
used as part of a complete sequence, but in
general should not be used by itself as a
single character control sequence.
CTRL-\ Used to tell SET HOST/DTE to end a connection to
a remote system.
DEL DELETE VMS line editing - delete prior character.
The following characters currently are not used by DCL and may be
employed in PEEK & SPY control sequences:
Recommended:
CTRL-G CTRL-K CTRL-L CTRL-N CTRL-W CTRL-\
CTRL-] CTRL-_ CTRL-~
Printable text characters may be used as part of a hot-key sequence
but should NOT be used as the initial character in such a sequence.