I've redirected stdout of a child process spawned with CreateProcess to a pipe. It works fine except that, as far as I can tell, no information about color changes are coming through. The child process is using SetConsoleTextAttribute to change the text color--is it possible to detect this through the pipe and, if so, how?
I'm ultimately displaying the output in a RichEdit control and I would like to capture the color information if at all possible.
This is in C with the Win32 API on XP and Vista.
You probably need to use ReadConsoleOutput (and/or related ones) found here: http://msdn.microsoft.com/en-us/library/ms682073(VS.85).aspx.
Hope that helps.
There maybe a work around...its old and not-used much!
Use Ansi.Sys and load that.
Whenever you output a text to the console, by using the Escape sequence, you can set a color around the text.
Then parse the escape sequences into the equivalent for RichText Colors.
The escape sequences are standard here. Here is how to add support for ANSI.SYS into the console. And here is the official KB from Microsoft on how to do this.
For an example:
printf("\x1b[33;43Yellow on Blue\x1b[0\n");
Now, parse the bit after the \x1b[, 33 is yellow foreground, and 43 is blue background, then look up the relevant color for that and set it in the RichTextBox..
Note: \x1b[0 turns off the attribute.
Edit: This may not be the best solution as that's for legacy NTVDM's 16bit DOS command.com under XP or later. But however, I found another link to 'ansicon' here which is for pure cmd.exe 32bit console, with ANSI support.
Hope this helps,
Best regards,
Tom.
Related
I'm trying to make a (somewhat) stylish DOS menu as a present for my father.
I was able to get the whole menu system to work, but I wanted to gussy it up with some box drawing characters and, possibly, colored text.
In this YouTube video, the user shows an example of what I'm trying to do (example at the 5:00 mark), but doesn't explain how those characters are being rendered. In the Notepad document, it is displayed as goofy characters.
Do I need to save the file with a special type of encoding? Can it only be done in Notepad (I'm using TextEdit on Mac)? Can someone provide an example menu that can be added to DOSBox's [autoexec] config?
Also, I'm not sure if it is possible, but how can the text color/background color be changed? When running DOSBox initially, it shows their welcome screen with a blue background and box drawing characters, so I would think all of that is possible.
I tried using escaped unicode characters and I tried using a capital-E acute (as shown in the linked video), but they just render funky stuff when run in DOSBox.
The discrepancy in characters is a result of different code pages being used in character rendering. English-speaking Windows uses ANSI code page 1252 (otherwise known as Latin-1), while DOS uses OEM code page 437, or IBM-PC.
The codepage that Windows uses will vary based on your system language, so you many need to experiment to find the correct characters, but basically, find the character you want to print in 437 (say ╔, which is 200) and then in your code use the 1252 version (where 200 is È). Then save the file in ANSI encoding.
I have been using the SoX play command line tool to playback audio files from the console, and have noticed that there is a nice little display of the time info and left/right levels that update in real time with the audio source . . .
Screenshot from SoX homepage
However, after cloning the source, I could not find any mention of Ncurses. Does anyone know how SoX achieves this neat little console trick? I just don't know what to look for, or which file to look in to see how this is implemented.
I doubt it's merely using the \b character. My guess would be that it's using the terminal cursor movement commands, which are a set of escape sequences supported by many (but not all) Linux terminals.
You can even use these straight from the command line using echo. For instance:
$ s=($(stty size)); echo -en "\e[2J\e[$((s[0]/2));$((s[1]/2-6))HHello world.\e[${s[0]};0H"
This should give you a blank screen, except for the the message "Hello world." printed right in the middle of the screen, and a prompt at the very bottom.
I've wrote a simple console program in C which uses ANSI escape codes to color its text.
Is there a way to temporarily set the background of the whole terminal to black and the default font color to light gray? Can this be reverted after the program ends?
I'd prefer to avoid using ncurses.
Probably the simplest way to go is to set the background colour of your text with ANSI:
For instance using:
echo -e "\e[37m\e[41m"
will give you blue text on a red background (you can use this to test the effect in dramatic, easy to see colours).
Whereas
echo -e "\e[97m\e[40m"
will set the foreground to white and the background to black for the duration of your program.
If you find that you're getting a kind of ugly transition zone between your background colour and the terminal's just print a sufficient number of newlines to wipe the whole screen.
To use this in C, you'll obviously want printf instead of echo.
The wiki page on ANSI escape codes has additional information.
How to do this depends on the terminal the user is using. It may be ANSI, it may be VT100, it might be a line printer. ncurses abstracts this horror for you. It uses a database of information about how to talk to different kinds of terminal (see the contents of $TERM to see which one you are currently using) normally stored in /lib/terminfo or /usr/share/terminfo.
Once you look in those files, you'll probably want to reconsider not using ncurses, unless you have specific requirements to avoid it (embedded system with not enough storage, etc.)
I think this is simple, but not for me obviously!
I have a console-application. I need to read input from the keyboard, but stdin has been redirected to a file. So how do I create a FILE-Handle that points at the keyboard-stream which i can use with fgets etc.?
I found out that ttyname(0) seems to be what i look for in a POSIX-environment, which I don't have here. I'm in a Windows-system with standard Visual Studio compiler.
Any ideas? Thank you in advance.
There's no easy/portable way to tell if a keyboard exists (your application may be being run from a terminal emulator from a serial port, a telnet session or anything else). If a keyboard actually does exist (including a picture of a keyboard on a touch screen), then you can't really tell how many layers of software the keystrokes need to pass through before they get to your application (e.g. keystrokes might go from a keyboard driver to an input method editor to a GUI to a shell to your application). This means that attempting to get keystrokes directly from a keyboard driver or something is a bad idea that will fail in almost all cases.
The best way to solve your problem is to find out which series of design failures led to STDIN being redirected in the first place.
For example; maybe the application should've had a command line option to read some data from a file; so that the application can get some data from the file and some from STDIN (and get all data from STDIN if the command line option isn't present).
Pulling from the dim dark days of DOS programming here: try opening "CON:" (Console), a reserved word. Hopefully it will open the same way in Windows. The colon may or may not be required. Both "dir >con:" and "dir >con" still work in command prompt.
Also, be sure to use something from the setbuf() family on the output handle to avoid buffering... it's not supposed to buffer terminal I/O, but it never hurts to be sure.
Again, not sure, but I suspect opening separate FILE *conin, *conout for output and one for input may help if you seem to have troubles with one handle doing both input and output.
In my C program I've had to swap my unicode box-drawing characters into escaped characters for DOS code page 437 to get it to work in the Windows command prompt. Is it possible to change the code page of gnome-terminal to display these characters correctly when natively compiling the program for linux?
Thanks.
From https://nethackwiki.com/wiki/IBMgraphics
The current gnome-terminal does not
have a setting for code page 437, but
it does support other code pages that
are equivalent for NetHack's purposes,
such as 862 (Hebrew).
To set code page 862 on
gnome-terminal:
Select Terminal->Set Character Encoding->Add or Remove.
In the pane on the left, select the line with description Hebrew and
encoding IBM862.
Click the right-pointing arrow between the two panes.
Click Close.
The above steps only need to be done
once for the lifetime of the Gnome
installation. Once done, it is
sufficient to:
Select Terminal, Set Character Encoding, and then Hebrew (IBM862).
It should be noted that the current
default gnome-terminal font in Ubuntu
Jaunty fully supports DECgraphics as
long as eight_bit_tty is set to false.
If you need these characters, you should use their correct Unicode codepoint values and output them as UTF-8. Or, if you prefer, you can output them as wide characters and let the standard library's locale system take care of converting them to UTF-8 or another "native" encoding the user has selected (which might even be CP437, although I've never seen a system setup that poorly...).