Using standard input and output on Android [closed]

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Using standard input and output on Android [closed]

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When I learned to program in Java, I used a lot of standard input and output (stdin and stdout). Now that I am curious to learn what I can do on Android, I wanted to know if for practicality I can do the same thing I did on the Java SE platform, which is: create a "console" application.

With a console application we can do some very practical things like:

Direct the output of the program to other Unix utilities (on Android requires Busybox).

am start -n com.example.android/.MainActivity | sort -u | sed ... > saída.txt

Or direct the output of other programs to my program's default input.

logcat|am start -n com.example.android/.MainActivity

I got to try out the Jackpal Terminal Emulator and I noticed that it uses these features:

Android absolutely supports pipes as well as unix domain sockets. Use   of exec is somewhat discouraged, but works at the moment.

See the source of any android terminal emulator with a local shell   an example of how to do it. Essentially your gui just   replaces the terminal emulator, and your engine replaces the shell.    Chris Stratton

// Create a stream to hold the output
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintStream ps = new PrintStream(baos);

// IMPORTANT: Save the old System.out!
PrintStream old = System.out;

// Tell Java to use your special stream
System.setOut(ps);

System.out.println("Foofoofoo!");
// Put things back
System.out.flush();
System.setOut(old);

baos.toString(); //Pega os dados

Then get this baos.toString(); and put it in a TextField or similar.

You can also change System.out.print by a function of your own that would make an append in TextField.

Using standard input and output on Android [closed]

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