[tcljava-dev] A patch for exec and errorCode

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

This patch is adapted from one sent in earlier.

Here is the Tcl behavior we want to match:

% catch {exec false} err
1
% set err
child process exited abnormally
% set errorCode
CHILDSTATUS 25301 1

Here is what the patched Jacl does:

% catch {exec false} err
1
% set err
child process exited abnormally
% set errorCode
CHILDSTATUS ?PID? 1

We don't have any way to find the
childs PID so I just put the
string ?PID? in there.


Here are a pair of test cases that
pass in Tcl and the patched Jacl.

test exec-4.1 { setting of errorCode when exit value != 0 } {
    set abnormal {child process exited abnormally}

    if {![catch {exec false} err]} {
        set result "exception not raised"
    } elseif {$err != $abnormal} {
        set result "expected $abnormal got $err"
    } elseif {[lindex $errorCode 0] != "CHILDSTATUS" ||
        [lindex $errorCode 2] != "1"} {
        set result "expected {CHILDSTATUS ?PID? 1} got $errorCode"
    } else {
        set result ok
    }
} ok

test exec-4.2 { no error when exit value == 0 } {
    list [catch {exec true} err] $err
} {0 {}}


And here is the patch:

Index: src/jacl/tcl/lang/ExecCmd.java
===================================================================
RCS file: /cvsroot/tcljava/tcljava/src/jacl/tcl/lang/ExecCmd.java,v
retrieving revision 1.5
diff -u -r1.5 ExecCmd.java
--- src/jacl/tcl/lang/ExecCmd.java	1999/05/17 03:50:37	1.5
+++ src/jacl/tcl/lang/ExecCmd.java	2001/02/28 08:59:32
@@ -151,6 +149,24 @@
 	    sbuf.setLength(length - 1);
 	}
 
+	// Tcl supports lots of child status conditions.
+	// Unfortunately, we can only find the child's
+	// exit status using the Java API
+        
+	if (exit != 0) {
+	    TclObject childstatus = TclList.newInstance();
+	    TclList.append(interp, childstatus,
+	        TclString.newInstance("CHILDSTATUS"));
+
+            // We don't know how to find the child's pid
+	    TclList.append(interp, childstatus,
+	        TclString.newInstance("?PID?"));
+
+	    TclList.append(interp, childstatus,
+	        TclInteger.newInstance(exit));
+
+            interp.setErrorCode( childstatus );
+	}
 
 	//when the subprocess writes to its stderr stream or returns
 	//a non zero result we generate an error


Does anyone see any problems with this change?

Mo DeJong
Red Hat Inc