DECOM sequence allows to the user defines a new home position. The home
position is used as base for all the movement commands except HVP and
VPA. It is important notice than DECSLM moves cursor to absolute position
0,0.
---
st.c | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)
After terminal reset saved terminal position is reset to 0, allowing know
where cursor will go in next restore cursor operation.
---
st.c | 2 ++
1 file changed, 2 insertions(+)
Since relational expresions are always evaluated to 0 or 1, we can use
bitwise xor operator instead of using more complex boolean expressions.
---
st.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
Sequences like DECSC, DECRC, ESC [?1047l or ESC [?1047h save and restore
cursor attributes, than taken from vt100 manual are:
Save Cursor (DECSC) ESC 7
===========================
Saves the following in terminal memory.
- cursor position
- graphic rendition
- character set shift state
- state of wrap flag
- state of origin mode
Restore Cursor (DECRC) ESC 8
===========================
Restores the states described for (DECSC) above. If none of these
characteristics were saved, the cursor moves to home position; origin
mode is reset; no character attributes are assigned; and the default
character set mapping is established.
This implies that hide attribute of the cursor should not be saved/restored
in these sequences. The best way to fix this problem is moving hide
attribute into the terminal mode, instead of having it in the cursor state.
---
st.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
write can write less bytes than we request, so it is necessary check the
return value, in case of error print a message and don't continnue writing
in the file.
---
st.c | 39 ++++++++++++++++++++++++++++++---------
1 file changed, 30 insertions(+), 9 deletions(-)
This sequence was used by DEC personal in to for verifying the screen adjust
of terminals. It is the unique test sequence implemented by all the
emulators, and I think it is because they want be conforms with vttest which
uses this sequence in some tests.
---
st.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
If vt100_0 is a automatic variable then it is initializated in each call to
tsetchar, but if the variable is static it is initializated only in compile
time.
---
st.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Do not send NUL character in the identification (use (sizeof(VT102ID) - 1),
and finish the sequence once you execute it.
---
st.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
These sequences are used by the host in order to can detect which kind of
terminal is connected. St will answer like a vt102 terminal with this patch.
---
st.c | 9 +++++++++
1 file changed, 9 insertions(+)
Non handled codes must be ignored, except in graphic mode. Also STR
sequences have higher priority than control codes, so they must be handled
before of them.
---
st.c | 160 ++++++++++++++++++++++++++++++++++++------------------------------
1 file changed, 87 insertions(+), 73 deletions(-)
SI and SO allows change the G0 and G1 selection. This implementation is not
full vt100 compatible, but it is complatible with linux virtual terminal
implementation. For full vt100 compatibility we need remake a lot of stuff
relate to the different charmaps.
---
st.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
Add the documentation from the vt100 manual programmer:
Control Octal Action Taken
Character Code
-------------------------------------------
NUL 000 Ignored on input (not stored in input buffer;
see full duplex protocol).
ENQ 005 Transmit answerback message.
BEL 007 Sound bell tone from keyboard.
BS 010 Move the cursor to the left one character position,
unless it is at the left margin,
in which case no action occurs.
HT 011 Move the cursor to the next tab stop,
or to the right margin if no further tab stops
are present on the line.
LF 012 This code causes a line feed or
a new line operation. (See new line mode).
VT 013 Interpreted as LF.
FF 014 Interpreted as LF.
CR 015 Move cursor to the left margin on the current line.
SO 016 Invoke G1 character set, as designated by SCS
control sequence.
SI 017 Select G0 character set, as selected by ESC ( sequence.
XON 021 Causes terminal to resume transmission.
XOFF 023 Causes terminal to stop transmitted all codes
except XOFF and XON.
CAN 030 If sent during a control sequence, the sequence is
immediately terminated and not executed. It also causes
the error character to be displayed.
SUB 032 Interpreted as CAN.
ESC 033 Invokes a control sequence.
DEL 177 Ignored on input (not stored in input buffer).
--------------------------------------------
---
st.c | 28 +++++++++++++++++++---------
1 file changed, 19 insertions(+), 9 deletions(-)
Roberto E. Vargas Caballero
Christoph Lohmann