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Index › Programming Questions & Help › Syntax Questions › System Commands

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System Commands (Read 1009 times)

orangeid

System Commands
Nov 11^th, 2009, 2:53pm

Hi There

Does anyone know if there is a way to run system commands in processing like os in python.

I have tried using open() but as the name suggest it only seem to open programs or files

here a example of what i am trying to do

Code:

void setup() {
  size(200, 200);
}

void draw() { 
  // draw() must be present for mousePressed() to work
}

void mousePressed() {
  open("echo info > /Test.txt");
}

Cheers

James

PhiLho

Re: System Commands
Reply #1 - Nov 12^th, 2009, 1:59am

Well, you know what? As I expected, your sketch just works!
But as you didn't expect, it writes the file at the root of C: (on my Windows system).
Why? Processing creates the sketches in the temp dir of your system, which is located, for me, on C:, somewhere in my user directory. It runs them from there, so current dir is this temp dir. You write on the root of the disk (the /Test.txt path), so data went there.

orangeid

Re: System Commands
Reply #2 - Nov 12^th, 2009, 5:42am

Hi Phil

Thanks for Replying

Thats strange maybe there's a difference between the Mac and PC

as i have tried with a full path and it still doesn't work

Code:


void setup() {
  size(200, 200);
}

void draw() { 
  // draw() must be present for mousePressed() to work
}

void mousePressed() {
  println("Opening Process_4");
  open("echo info >/Users/james/Desktop/test_001.txt");
}

My main aim is to run a script but it justs opens the text file up instead, any suggestions

Cheers

James

mhuyck

Re: System Commands
Reply #3 - Nov 12^th, 2009, 8:13am

Hi James,

On the Mac, open() does the equivalent of what would happen if you double-clicked on the file you specified, which may be why your script is opening in an editor instead. If you are using something like AppleScript, you should save the file as an Application using the AppleScript Editor. Check that double-clicking will run rather than open the file and then try again.

Re-read the documentation for the open() command and "man open" on the Mac closely for details on the platform-specific differences:

http://processing.org/reference/open_.html

If you have an actual shell script rather than an AppleScript, then you might try the exec(String[]) command mentioned above.

I hope this helps!

-Matt

blindfish

Re: System Commands
Reply #4 - Nov 12^th, 2009, 8:14am

OK maybe I'm showing my ignorance of Macs but that still looks like a relative path:

/Users/james/Desktop/test_001.txt

Surely that's still relative to 'root' which, as PhilHo suggested, your program will presumably interpret as running from its root, not your system root...

On a PC a full path would start with a drive letter:

C:/etc...

Where is the what if the what is in why?

PhiLho

Re: System Commands
Reply #5 - Nov 12^th, 2009, 8:34am

blindfish, on Unix systems (that's what MacOS is, now), a path starting with slash is an absolute path. Well, that's also the definition of a path relative to the root dir...

(system root, I know no other, actually).

Actually, this also applies to Windows systems as well: foo/bar (or foo\bar, that's the same on XP and above) is a relative path, /foo/bar is an absolute path (or actually relative to root of current drive).

blindfish God Member Offline Posts: 793	Re: System Commands Reply #6 - Nov 12^th, 2009, 8:43am Ah - OK... I'm applying my experience of a different environment where it's not relevant: I've used one authoring tool which treats '/' as the root directory of the application rather than system root. That and my brain hurts today
	Where is the what if the what is in why?

orangeid YaBB Newbies Offline Posts: 8	Re: System Commands Reply #7 - Nov 12^th, 2009, 3:07pm Hi Matt The exec() was exactly what i was after. Many Thanks James

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