tcljava-user

[tcljava-user] HELP...Calling TCL scripts from a Java program

[Tam H. <th...@su...>]

I'm trying to execute a Tcl script from a java program using the java
Runtime class.  However, the script does not execute because my log file is
never created.  Should i stick to this Runtime class or use something like
Tcl blend to include a class to call the script.  I'm just trying to find
the quickest solution to call the script, pass it parameters, and get
results from the script in return..Am i even calling the script the right
way?


Any suggestions would be appreciated!!


TCL SCRIPT:
set f "log.txt"
set out [open $f w]

puts $out $argv0
puts $out $argv1
puts $out $argv2

close $out


JAVA PROGRAM:
  public static void main(String args[])
    {
        try
        {
            String s;
            String[] argv = {"hey", "there", "buddy"};
            String[] cmd = new String[2];
            cmd[0] = "d:\\Tcl83\\bin\\wish83.exe";
            cmd[1] = "d:\\cygwin\\bin\\hello.tcl";

            Process myProcess = Runtime.getRuntime().exec(cmd, argv);
            myProcess.waitFor();
            System.out.println("Process exit code is: " +
myProcess.exitValue());

            DataInputStream in = new
DataInputStream(myProcess.getInputStream());
                 while ((s = in.readLine()) != null) {
                    System.out.println(s);
                }
        }
        catch (Throwable t)
        {
            System.err.println(t);
            t.printStackTrace();
            //Ensure the application exits with an error condition.
            System.exit(1);
        }
    }

[tcljava-user] HELP...Calling TCL scripts from a Java program

[Tam H. <th...@su...>]

ok, i'm trying the other approach by using the binary version of Jacl 1.2.6.
i'm trying to call the tcl script as describe below..am i missing any kind
of patch for jacl?  both tcljava.jar and jacl.jar are on my classpath and
i'm using Forte for Java 1.0.  i know the interp object is created bc it's
fine when i type newInterp.eval("puts {hello there}"), but doesn't invoke my
script when i use "source"..

ERRORS:

tcl.lang.TclVarException
tcl.lang.TclVarException
        at tcl.lang.Var.lookupVar(Var.java)
        at tcl.lang.Var.getVar(Var.java)
        at tcl.lang.Parser.evalTokens(Parser.java)
        at tcl.lang.Parser.eval2(Parser.java)
        at tcl.lang.Interp.eval(Interp.java)
        at tcl.lang.Interp.evalFile(Interp.java)
        at tcl.lang.SourceCmd.cmdProc(SourceCmd.java)
        at tcl.lang.AutoloadStub.cmdProc(Extension.java)
        at tcl.lang.Parser.evalObjv(Parser.java)
        at tcl.lang.Parser.eval2(Parser.java)
        at tcl.lang.Interp.eval(Interp.java)
        at tcl.lang.Interp.eval(Interp.java)
        at com.nwoods.jgo.examples.demo1.Demo1.main(Demo1.java:1006)


JAVA PROGRAM:
import tcl.lang.*;



  public static void main(String args[])
    {
        try
        {
		Interp newInterp = new Interp();
	    newInterp.eval("source d:/Tcl83/bin/hello.tcl");
            newInterp.dispose();
		}
        catch (Throwable t)
        {
            System.err.println(t);
            t.printStackTrace();
            //Ensure the application exits with an error condition.
            System.exit(1);
        }
    }

Re: [tcljava-user] HELP...Calling TCL scripts from a Java program

[Mo D. <md...@cy...>]

On Sat, 12 May 2001, Tam Huynh wrote:

> ok, i'm trying the other approach by using the binary version of Jacl 1.2.6.
> i'm trying to call the tcl script as describe below..am i missing any kind
> of patch for jacl?  both tcljava.jar and jacl.jar are on my classpath and
> i'm using Forte for Java 1.0.  i know the interp object is created bc it's
> fine when i type newInterp.eval("puts {hello there}"), but doesn't invoke my
> script when i use "source"..
> 
> ERRORS:
> 
> tcl.lang.TclVarException
> tcl.lang.TclVarException
>         at tcl.lang.Var.lookupVar(Var.java)
>         at tcl.lang.Var.getVar(Var.java)
>         at tcl.lang.Parser.evalTokens(Parser.java)
>         at tcl.lang.Parser.eval2(Parser.java)
>         at tcl.lang.Interp.eval(Interp.java)
>         at tcl.lang.Interp.evalFile(Interp.java)
>         at tcl.lang.SourceCmd.cmdProc(SourceCmd.java)
>         at tcl.lang.AutoloadStub.cmdProc(Extension.java)
>         at tcl.lang.Parser.evalObjv(Parser.java)
>         at tcl.lang.Parser.eval2(Parser.java)
>         at tcl.lang.Interp.eval(Interp.java)
>         at tcl.lang.Interp.eval(Interp.java)
>         at com.nwoods.jgo.examples.demo1.Demo1.main(Demo1.java:1006)
> 
> 
> JAVA PROGRAM:
> import tcl.lang.*;
> 
> 
> 
>   public static void main(String args[])
>     {
>         try
>         {
> 		Interp newInterp = new Interp();
> 	    newInterp.eval("source d:/Tcl83/bin/hello.tcl");
>             newInterp.dispose();
> 		}
>         catch (Throwable t)
>         {
>             System.err.println(t);
>             t.printStackTrace();
>             //Ensure the application exits with an error condition.
>             System.exit(1);
>         }
>     }

Well, I don't know why running the source command would
do that. It is running Interp.evalFile() which should
eval the contents of the file. Could you poke around in
a debugger to find out why this variable error is being
generated? Is your script using a variable that is
not set?

Mo

Re: [tcljava-user] HELP...Calling TCL scripts from a Java program

[Mo D. <md...@cy...>]

On Thu, 10 May 2001, Tam Huynh wrote:

> I'm trying to execute a Tcl script from a java program using the java
> Runtime class.  However, the script does not execute because my log file is
> never created.  Should i stick to this Runtime class or use something like
> Tcl blend to include a class to call the script.  I'm just trying to find
> the quickest solution to call the script, pass it parameters, and get
> results from the script in return..Am i even calling the script the right
> way?

Running tclsh from a Java application should not be that hard.
Trouble is, the Java implementation from Sun is really full
of bugs under Windows. You could take a look at the Jacl
implementation of the exec command for Tcl. I have to warn
you, it is a bit scary!

> Any suggestions would be appreciated!!

Have you considered using Jacl? Jacl is a Tcl interp
written in 100% Java. Adding Jacl to your existing Java
application might be easier, you just add tcljava.jar
and jacl.jar to the CLASSPATH and then create a tcl.lang.Interp
object.

Mo DeJong
Red Hat Inc

Re: [tcljava-user] HELP...Calling TCL scripts from a Java program

[D. J. H. <dha...@mi...>]

The fundamental problem here is that Runtime.exec(...) is a very
primitive interface and hard to use correctly, especially to capture
large chunks of output from stdout/stderr or input large chunks
of data to stdin.

The following article on JavaWorld provides a good example at the end:

http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html

I don't know if this "fix" has yet been applied to Jacl's exec, 
per Mo's reply, but I was intending to do so someday if someone
hasn't already...

In addition, you should really use a BufferedReader(InputStreamReader())
chain around the exec'd process output if you want to capture text
lines.
DataInputStream is for binary struct-type and serialized Java object
data, not text.

			-=- D. J.

Tam Huynh wrote:
> I'm trying to execute a Tcl script from a java program using the java
> Runtime class.  However, the script does not execute because my log file is
> never created.  Should i stick to this Runtime class or use something like
> Tcl blend to include a class to call the script.  I'm just trying to find
> the quickest solution to call the script, pass it parameters, and get
> results from the script in return..Am i even calling the script the right
> way?
[ . . . ]
>             Process myProcess = Runtime.getRuntime().exec(cmd, argv);
>             myProcess.waitFor();
>             System.out.println("Process exit code is: " +
> myProcess.exitValue());
> 
>             DataInputStream in = new
> DataInputStream(myProcess.getInputStream());
[ . . . ]