So, I have a chat server in python (using twisted) setup, to which users connect using telnet. The problem is, when someone sends a message while someone else is typing one, the sent message will overwrite the one that is being typed. My current solution is to delete the line the cursor is on (with the \033[2K ANSI escape sequence, followed by \r), and replace it with the message, but obviously, people won't like it if their draft message gets deleted every time someone else sends one. I have tried to use escape sequences to
save the cursor's position,
go to the beginning of the line,
insert the message followed by a new line, and
return to the message by going to the saved position and going one line down.
However, the draft message gets overwritten by the sent one, instead of getting pushed aside. So my question is, is there a way to insert the sent message before the draft one without overwriting it, and then return the cursor to the message for further typing?
I've managed to avoid creating my own client, and instead, I'm using stty -icanon && nc {CHAT IP} {CHAT PORT}. On the server side, I've created a buffer to hold the message that is being typed, and to edit it accordingly and reprint it when it receives the character code for the backspace key. When it receives the character code for the arrow keys, it keeps track of the cursor and sends the escape codes to move the cursor accordingly.
Related
I want to create a script that triggers when pressing Q twice while holding Alt, but couldn't figure out what're the correct key codes for that, could someone please shed some light?
P.S. I want to bind this shortcut to Ctrl+F12, which I assigned Sogou IME to turn on the Chinese input mode.
I didn't test this and there's probably a more concise way to do it, but I think something like this should work.
!Q::
If(keyPressed = 1){
...Do a thing...
}
keyPressed := 1
SetTimer, altQTimer, 50
return
altQTimer:
keyPressed := 0
return
TL;DR
In conclusion, even if I do all kinds of hacks and get the script working as intended, it's likely to break in the future, which is really not worth the trouble.
After hours of experimenting, the current conclusion is Sogou IME which uses Ctrl+F12 won't trigger the bound action i.e. switching to the Chinese input mode if it was sent by Alt+[Any Other Key], it can be triggered if it was sent by other shortcuts such as Ctrl+C, which is really unfortunate.
And the weirdest thing is the following code works:
^c::Send !q
!q::Send ^{F12}
And to rule out the potential extra simulated keystrokes (Ctrl by default) effect, the following code also works:
^!q::Send ^{F12}
But the following doesn't (tested on several machines):
!q::Send ^{F12}
Update
After much effort, I did get Alt+Q to turn on the Chinese input mode with the following code, not sure why:
!q::Send ^{F6}
^F6::Send ^{F7}
^F7::Send ^{F12}
But because I also need to trigger a VSCode command using Alt+Q at the same time, I had to modify the above code to the following:
~!q::Send ^{F6} ; with ~ prefixed
^F6::Send ^{F7}
^F7::Send ^{F12}
Now Alt+Q does trigger the VSCode command, but it won't turn on the Chinese input mode...
At last, if I take a step back and bind the VSCode command to Ctrl+C (which could turn on the Chinese input mode with just ^c::Send ^{F12}), I still have to prefix ^c with ~, otherwise it won't trigger the VSCode command, now I'm repeating the cycle all over again...
After all of these attempts, I have to say Sogou IME's logic for determining whether to enable the Chinese input mode is quite indeterminate, making the script for enabling the Chinese input mode very unreliable.
In conclusion, even if I do all kinds of hacks and get the script working as intended, it's likely to break in the future, which is really not worth the trouble.
Reading a text file (which happens to be a PDS Member FB 80)
hFile = fopen(filename,"r");
and have reached up to the point in the file where there is only an empty line left.
FilePos = ftell(hFile);
Then read the last line, which only contains a '\n' character.
fseek(hFile, FilePos, SEEK_SET);
fails with:-
errno=(27) EDC5027I The position specified to fseek() was invalid.
The position specified to fseek() was returned by ftell() a few lines earlier. It has the value 841 in the specific error case I have seen. Checking through the debugger, this is also the value returned by ftell a few lines earlier. It has not been corrupted.
The same code works at other positions in the file, and only fails at the point where there is a single empty line left to read when the position is remembered.
My understanding of how ftell/fseek should work is succinctly captured by another answer on SO.
The value returned from ftell on a text stream has no predictable relationship to the number of characters you have read so far. The only thing you can rely on is that you can use it subsequently as the offset argument to fseek or fseeko to move back to the same file position.
It would seem that I cannot rely on the one thing I should be able to rely on.
My questions is, why does fseek fail in this way?
As z/OS has some file formats that are unique you might find the answer in this Knowledge Center article.
Given that you are processing a PDS member I would suspect that this is record level I/O which is handled differently than stream I/O which is more common in distributed implementations.
I do not know why fseek fails in this way, but if your common usage pattern is to use ftell to get the position and then fseek to go to that position, I strongly suggest using fgetpos and fsetpos instead for data set I/O. Not only will you avoid this problem that you are finding, but it is also better performing for certain data set characteristics.
I am trying to setup a program that takes user input for database ddl generation. I have it working to the point where it can ask a user for the name of the table, the number of columns and any attributes that might be needed. The problem comes when I try to print a string that includes the variables used for the column names. Due to trying to let users have as many columns as they want I used variables similar to this newvar(number that increases every time you enter a column name). This works fine and I can get the values if i do send %newvar1% but it doesn't work to do send newvar%increasing number%. I need to know if this is possible or if I'm just missing something obvious. Also I don't have the code with me but I can post it once I get back to my main computer.
I have tried quite a few things like, send %newvar%%number%, send newvar%number%, othervar = newvar%number% send %othervar%.
I'll show some once I have access to it in about 2 hours.
I expect to be able to output names for increasing variables using an ever increasing number. Class is starting I'll clarify some things later.
You can use a lone percent % beginning the first argument for the send command to achieve what you want. This will make everything after it to be evaluated (up to the next comma). Here is an example:
f1::
newvar1 := "This " , newvar2 := "is just a " , newvar3 := "test."
Loop , 3
Send , % newvar%A_Index%
Return
See: https://www.autohotkey.com/docs/Language.htm#-expression
Hi I want to take input from user in my
DO BEGIN and END block...
I tried to use /prompt inside but it doesnt work.
Do we have any other way that we can use it inside function or block in postgres?
Important note: PLpgSQL is server side only language - there is not any possibility do any user interactivity operation. You have to collect input on client side before start of PLpgSQL code, and user input push there as parameters.
DO statement is server side statement, so you cannot do any interactive action there.
DO statement doesn't support parameters so it is not easy push any parameters inside DO statement, but is possible with custom configuration variables:
\prompt 'enter some text: ' psqlvar
\o /dev/null
select set_config('psql.psqlvar', :'psqlvar', false);
\o
do $$
DECLARE var text = current_setting('psql.psqlvar');
BEGIN
RAISE NOTICE 'entered text is: %', var;
END;
$$;
The function set_config is used to moving a content of client variable :psqlvar to server side - session variable psql.psqlvar. The content of this server side variable is taken by function current_setting.
You have to separate in your mind server side and client side content. The DO statement is evaluated on server side. The psql \prompt command is evaluated on client side.
As bad ideas go, asking for user input in a stored procedure is up there with using usernames as session identifiers. This is a really, really bad idea. Yes there are ways in some environmnets to do this. But just because you can does not mean you should. For example I have heard of people using pl/python to make a network connection back to the client computer and ask for more information. However, this is frankly DailyWTF territory. It also assumes a protocol and listener on the client to ask for this request and therefore doesn't work from pgadmin.
Now, DO creates an anonymous function without arguments and immediately executes it. This seems to be where your real problem is.
Your best solution is to just create an actual function with arguments and accept the input there. Then it can be used anywhere. And you can re-use, modify security, etc. This sounds like it is exactly what you need.
Failing that you could preprocess your do block before you send it.
Your best design where you want to reuse PL/PGSQL code with inputs is to use a function (see CREATE FUNCTION) instead of DO (note you can put these in another schema if that is a concern).
I am working on a small RTE in a contentEditable DIV. I have attached a keypress event handler to the DIV that monitors when the ENTER key is struck and where the selection is. If it is inside a text node, I am inserting a new line. However, this code is buggy and often inserts 4 newlines instead of one (I have to press undo 4 times to get back to where the cursor was before - that's why I think execCommand is firing multiple times). On the other hand, it sometimes requires TWO strikes of the ENTER key to get a new line inserted.
here is a code snippet of the keypress event handler, once it's determined that the ENTER key has been pressed:
if(selection.focusNode.nodeType!=3){ return; }
ev.preventDefault();
var HTML='
';
toolbar.target.ownerDocument.execCommand('insertHTML',false,HTML);
I want to use execCommand to preserve the browser's undo behavior. I do NOT want to insert a <br> as this insertion only happens in a text node and for post-processing purposes, I need \n in the text nodes instead of <br>'s or any other block-type tags. I am using the unicode newline character
. I have tried the carriage return character
as well with similar results. I can't use \n with insertHTML because that is not proper HTML.
Anyone have ideas about how to make sure that execCommand runs ONLY once?