Re: Non-blocking keyboard input
On Sunday, 14 January 2024 at 13:41:26 UTC, Joe wrote: This does not actually work on my computer. It still blocks. Adam is no longer using mainstream D, and apparently not posting on this forum. I suggest you try to contact him via the arsd github page: https://github.com/adamdruppe/arsd -Steve
Re: Non-blocking keyboard input
On Wednesday, 27 December 2023 at 13:27:53 UTC, Adam D Ruppe
wrote:
On Wednesday, 27 December 2023 at 05:07:04 UTC, Joe wrote:
??? Surely there there is
a one liner library solution for this?
It is not one line because it needs a bit of setup (and
teardown, but the objects' destructors do that for you) but it
is close:
http://arsd-official.dpldocs.info/arsd.terminal.html#single-key
`input.getch` waits for a single line, but you can use
`if(input.kbhit())` to see if it would block before calling it.
This shouldn't be hard... yet it is.
Better be careful, the mods are out in force deleting posts
this week that tell the hard truth. But yeah, the stdlib in D
has very little activity:
https://github.com/dlang/phobos/graphs/contributors?
So you can't expect much from it. My arsd libs provide a broad
set of functionality missing from it: stuff like this
terminal/console stuff, window creation, basic guis, web
servers, etc.
If you want to try them, you can use it from the dub system,
but I recommend just `git clone
https://github.com/adamdruppe/arsd.git` in your working
directory then import what you want and use `dmd -i` to
automatically include them in the build.
This does not actually work on my computer. It still blocks.
int itr = 0;
for(;;)
{
itr++;
writeln("1. closeKBThread = ", closeKBThread, ", iter = ",
itr);
if (closeKBThread) return;
string op = "";
string istr = "";
while (!closeKBThread)
{
writeln("2. ", input.kbhit(), " ",
closeKBThread);
if (input.kbhit())
{
istr ~= input.getch(false);
break;
}
}
writeln("final istr = ", istr);
1. closeKBThread = false, iter = 1
2. false false
2. false false
2. false false
2. false false
final istr = f
1. closeKBThread = false, iter = 2
2. false false < now blocking
All this is just junk of me trying to figure out what was going
on, but literally input.kbhit blocks after the first run(which
really means it's always blocking)
My original code was
while(true)
{
if (input.kbhit()) { istr ~= input.getch(); break; }
}
and I've been trying all kinds of stuff to figure out what was
going on but I believe it is the kbhit function itself. It calls
getch(true) and blocks on that as if I were just using getch
itself.
The issue is the same, the code does not block then after I hit a
key and it goes through an iteration of the outside loop it then
blocks waiting for the next input.
Re: Non-blocking keyboard input
On Wednesday, 27 December 2023 at 14:41:05 UTC, Christian Köstlin wrote: One option (not tested) should be to close stdin so that readln then returns null or something on eof. Shutting down threads is always tricky. It would be great if there would be one or two (perhaps one synchronous, one asynchronous) main io-frameworks for dlang (also as dub packages) that cover the most common use-cases. Kind regards, Christian I tested this now, but it still blocks in readln ... Kind regards, Christian
Re: Non-blocking keyboard input
On Wednesday, 27 December 2023 at 05:07:04 UTC, Joe wrote: ??? Surely there there is a one liner library solution for this? I have a program that spawns a thread for debugging information and uses the keyboard input which allows me to display the information. If I use getchar or readline then it blocks the thread. This is generally fine because that is all the thread does. The problem is that it also blocks the program termination as the main thread will not exit while the thread is running which is is because it's waiting on keyboard input stuck on getchar or fgetc or whatever. If I terminate the threads using thread_term then it terminates the program but the program then does not return the return code that it was successfully finished(because it was prematurely terminated by thread_term. Surely there is some type of peek for keyboards in D? I can't seem to get kbhit or because the library is not included(well, I tried to use one from dmc but it seemed to be invalid. snn.lib IIRC). This shouldn't be hard... yet it is. One option (not tested) should be to close stdin so that readln then returns null or something on eof. Shutting down threads is always tricky. It would be great if there would be one or two (perhaps one synchronous, one asynchronous) main io-frameworks for dlang (also as dub packages) that cover the most common use-cases. Kind regards, Christian
Re: Non-blocking keyboard input
On Wednesday, 27 December 2023 at 05:07:04 UTC, Joe wrote: ??? Surely there there is a one liner library solution for this? It is not one line because it needs a bit of setup (and teardown, but the objects' destructors do that for you) but it is close: http://arsd-official.dpldocs.info/arsd.terminal.html#single-key `input.getch` waits for a single line, but you can use `if(input.kbhit())` to see if it would block before calling it. This shouldn't be hard... yet it is. Better be careful, the mods are out in force deleting posts this week that tell the hard truth. But yeah, the stdlib in D has very little activity: https://github.com/dlang/phobos/graphs/contributors? So you can't expect much from it. My arsd libs provide a broad set of functionality missing from it: stuff like this terminal/console stuff, window creation, basic guis, web servers, etc. If you want to try them, you can use it from the dub system, but I recommend just `git clone https://github.com/adamdruppe/arsd.git` in your working directory then import what you want and use `dmd -i` to automatically include them in the build.
Non-blocking keyboard input
??? Surely there there is a one liner library solution for this? I have a program that spawns a thread for debugging information and uses the keyboard input which allows me to display the information. If I use getchar or readline then it blocks the thread. This is generally fine because that is all the thread does. The problem is that it also blocks the program termination as the main thread will not exit while the thread is running which is is because it's waiting on keyboard input stuck on getchar or fgetc or whatever. If I terminate the threads using thread_term then it terminates the program but the program then does not return the return code that it was successfully finished(because it was prematurely terminated by thread_term. Surely there is some type of peek for keyboards in D? I can't seem to get kbhit or because the library is not included(well, I tried to use one from dmc but it seemed to be invalid. snn.lib IIRC). This shouldn't be hard... yet it is.
