I'm using WaitForString command to pause my script until the desired text appears on screen. However I notice that the screen stops "printing" as soon as that happens. I'd rather wait until the whole screen finishes refreshing.
I suspect that instead of WaitForString("text"), I could use WaitForCursor; when the screen is complete, I can use Get("text").
However, I cannot find any documentation that explains the WaitForCursor command. How would I use it in this case?
Have a read through of this manual for secure-crt and scripting with vbscript
Scripting Essentials (PDF)
I expect you would use the command itself as crt.Screen.WaitForCursor(timeout) although I've never used this software myself so that's just a guess
Related
Several *NIX commands, such as screen, man, vim and others, create a temporary canvas/screen/overlay in a shell environment. When such programs execute, they cover or hide whatever content was displayed in the terminal before — almost like a "full screen" mode, within the terminal window. When they terminate, however, they reveal or restore whatever had been on the terminal before.
In the example below, I create some filler text on the screen, then invoke man bash. The man page opens up and covers all other characters on the terminal display. When I close the man page, the characters that had been covered up are again shown.
Before
While an example full-screen program is running
After
I would expect that programs writing to stdout/stderr could accomplish the first step (replacing the content of the terminal with program-specific content), but then it would produce a ton of text that I could scroll through, and therefore couldn't do the second step: restoring the contents of the terminal. That means that somehow either the program memorizes the previous contents of the screen and re-outputs them (I doubt it?), or it creates some sort of sub-window within a terminal and something else keeps track of the previous contents of the terminal.
My Question
How can I accomplish that behavior in my own program and/or script?
Perhaps I should use curses/ncurses, tput, termcap/terminfo, or ANSI escape sequences?
Update:
This revised question is essentially the same as https://unix.stackexchange.com/questions/27941/show-output-on-another-screen-and-return-to-normal-when-done. (I hadn't found it when I had written this question despite lots of searching.) The difference is that my question is more general (any language) whereas that question is specific to Bash. The answers to both questions are essentially the same. If it's too similar to a question on another site, feel free to close it here for that reason.
How do these programs accomplish that behavior?
ANSI escape sequences. Try running this script:
#/bin/bash -
tput smcup
echo 'Hello world!'
sleep 3
tput rmcup
Using infocmp, you can see underlying sequences that create this overlaying effect, e.g:
$ infocmp -1 | grep 'rmcup\|smcup'
rmcup=\E[?1049l\E[23;0;0t,
smcup=\E[?1049h\E[22;0;0t,
is this behavior shell-dependent or system-dependent?
None, it depends on whether the terminal emulator supports save/restore operations.
sometimes in terminal when I type a long command, instead of continuing in the next line it starts to write at the same line and I cannot see what I am typing. What is the reason and how should I make it fine?
Sometimes if you resize a terminal window while in a fullscreen command (say inside "vim" or "less"), when you exit back to the shell it will assume your terminal has the old dimensions, and will show the behavior you are describing. See this question: https://unix.stackexchange.com/questions/61584/how-to-solve-the-issue-that-a-terminal-screen-is-messed-up-usually-after-a-res
Also, please in the future post this kind of questions in unix.stackexchange.com as this one is not strictly a programming question.
I am trying to create a program which will have live updates from some data source. And I also want to wait for user input just like a normal terminal. Right now, whenever there is update, I will print the content and print the prompt message for input again which create something like this:
Enter command >
This is a live update message
Enter command >
This is a multi-line li......
......ve update message
Enter command > quit
Bye bye!
The problem is that for every live message I received, I will print it and the "Enter command >" will be displayed again again and again, which is not desired. I want the live update to be update on the main part of the terminal, while the "Enter command >" always stay at the bottom
The closest package I can found on Github is https://github.com/gizak/termui but most of the examples inside is trying to display text, gauge and graphs. So I am not quite sure how to get started.
Is there any package or example of the termui package to achieve this? Thank you.
With github.com/gizak/termui you're heading in the correct direction.
To understand why you can't get that
I want the live update to be update on the main part of the terminal, while the "Enter command >" always stay at the bottom
part sorted out, a little excursion to the history of computing is due. ;-)
The thing is, the mode your teminal emulator¹ works by default originated
in how computers would communicate to the operator in the era which predated
alphanumeric displays — they would print their responses using a line printer. Now think of it: a line printer works like this: it prints whatever is sent to it on a roll of paper. What was output, was output.
The new output always appears physically below the older.
When alphanumeric displays (screens) came into existence they
naturally continued to support this mode:
the line text to be output was rendered at the bottom of the screen
with the text above it scrolled upwards.
That's what you see in your typical terminal emulator all the time when you're working in the command line of a shell (such as bash) running by the emulator window.
This, default, work mode of a terminal is called "canonical" or "cooked".
Then came more advanced displays, for which it was possible to change
individual positions on the screen — identified by their column and
row numbers.
This changed the paradigm of how the information was output: the concept
of a so-called "full-screen application" was born.
Typical examples of them are text editors such as Vim and Emacs.
To support full-screen text output, terminals (and terminal emulators)
were adapted by implementing certain extensions to their protocols.
A full-screen application first requests the terminal to switch into another
mode called "raw", in which the terminal sends most of what is input by the
user directly to the program running on the terminal.
The program handles this input and orders the terminal where and what
to draw.
You can read this good summary
of the distinction between the both modes.
As you are supposedly suspecting by now, to be able to keep some block
of information at a certain fixed place of the terminal's text screen,
you want your program to be a full-screen program and use the terminal's
raw mode and its special commands allowing you to directly modify
text at certain character cells.
Now the problem is that different terminals (and terminal emulators)
have different commands to do that, so there exist libraries to isolate
the programs from these gory details. They rely on the special "terminal
information databases" to figure out what capabilities a terminal has
and how to make it do what the program asks.
See man terminfo for more background.
The most widely known such library (written in C) is called ncurses,
and there exist native solutions for Go with supposedly the most visible
one being github.com/nsf/termbox-go.
The github.com/gizak/termui makes use of termbox-go but for you it might
suffice to use the latter directly.
¹ Chances are very high you're not sitting at
a real hardware terminal
connected to a UNIX® machine but are rather working in a GUI application
such as GNOME Terminal or xterm or Termial.app etc.
These are not "terminals" per se but are rather
terminal emulators —
that is, pieces of software emulating a hardware terminal.
Is there a way in which I can debug my compiled Matlab components, using native Matlab debugger, like Visual Studio "Attach to process" option, or something like that?
I mean EXE stand-alone files, DLLs, COM in-process servers or .NET components.
You can't debug them in the sense of being able to step through the MATLAB code line by line, as you can with MATLAB's own debugger prior to compilation. One of the steps that the MATLAB deployment products take is to encrypt the MATLAB code (so you can preserve your IP when distributing the deployed component). The ability to step through the code in a debugger after deployment would defeat the purpose of that.
I experimented with using something like :
try
catch ME
waitbar(0,ME.message)
end
This was quite an effective and generic solution.
you may want to break down the code into multiple parts and debug each to save compiling time.
good luck,
dan
You can follow the instructions to debug:
Debugging:
Using the Debugging Tool will let you stop your program in mid-execution to examine the contents of variables and other things which can help you find mistakes in your program. M-file programs are stopped at "breakpoints". To create a breakpoint, simply press F12 and a red dot will appear next to the line where your cursor is. You can also click on the dash next to the line number on the left side of the M-file window to achieve the same result.
Then press F5 or Debug->Run from the menu to run the program. It will stop at the breakpoint with a green arrow next to it. You can then examine the contents of variables in the workspace, step, continue or stop your program using the Debug menu. To examine contents of a variable, simply type its name into the workspace, but be warned: you can only look at the values of variables in the file you stop in, so this means that you'll probably need multiple breakpoints to find the source of your problem. There are several different ways you can move through the program from a breakpoint. One way is to go through the whole program, line by line, entering every function that is called. This is effective if you don't know where the problem is. There's also a way to simply step through the function you're currently stopped in, one line at a time, and instead of going through the child functions line by line MATLAB will simply give you the results of those functions.
Finally, note that you cannot set a breakpoint until you save the M-file. If you change something, you must save before the breakpoint "notices" your changes. This situation is depicted in MATLAB by changing the dots from red to gray. Sometimes, you'll save but the dots will still be gray; this occurs when you have more than one breakpoint in multiple files. To get around this (which is really annoying), you have to keep going to "exit debug mode" until it turns gray. Once you're completely out of debug mode, your file will save and you'll be ready to start another round of debugging. Using comments to help you debug code. you want to test the effects of leaving out certain lines of code (to see, for example, if the program still returns Inf if you take them out), you can comment out the code. To do this, highlight it and then go to:
Text -> Comment
Or press CTRL+R. This will simply put a '%' in front of every line; if the line is already commented out it will put another '%' there so when you uncomment them the pattern of comment lines will not change. Commented lines will be ignored by the compiler, so the effect will be that the program is run without them.
To uncomment a line go to
Text -> Uncomment
Or press CTRL+T.
Another use of commenting is to test the difference between two different possible sets of code to do something (for example, you may want to test the effect of using ODE113 as opposed to ODE45 to solve a differential equation, so you'd have one line calling each). You can test the difference by commenting one out and running the program, then uncommenting that one and commenting the other one out, and calling the program again.
How to escape infinite loops?
MATLAB can't directly tell you you have an infinite loop, it does attempt to give you some hints. The first comes when you terminate the program. Terminate it by pressing CTRL+C and MATLAB will give you a message telling you exactly what line you stopped on. If your program is running a long time, it is likely the line you stopped in is in the middle of an infinite loop. sometimes MATLAB won't even let you return to the main window to press CTRL-C. In this case you probably have to kill the whole MATLAB process. After this, add a "pause (0.001)" or a similarly small value in the loop you suspect to be the infinite one. Whenever MATLAB passes this instruction you will be able to interact with MATLAB for a (very) short time, e.g. go to the main window and press CTRL-C with MATLAB being able to respond to your command.
The problem I face is this:
I would like to have in a context menu (when i right-click on a folder) an action to be executed and display the output to the user, inside, let's say, a text area window with a vertical scrolling bar. Suppose, that the action is just a shell script that executes a "find" command inside the given directory, searching for a specified pattern.
I have managed to implement it, up to this point, using Automator. What I cannot do is to pipe the output in a synchronous fashion (what is meant by "synchronous" is to have the output print to the user when is produced by the "find" command, and not after the command has finished) in a GUI.
I have spent sometime searching on this and I have come to the conclusion that XCode and Interface Builder have to be put into the play? Am I on the right track? Is there a straightforward and simple way in succeeding in this without having to dig into this framework?
Thank you very much,
Babis
You can have the shell script throw a dialog when it gets the result using http://cocoadialog.sourceforge.net/