--- a/TerminalSession.st	Fri Dec 22 15:36:27 2017 +0100
+++ b/TerminalSession.st	Sat Dec 23 13:34:32 2017 +0100
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 2013 by eXept Software AG
               All Rights Reserved
@@ -83,23 +85,32 @@
 !TerminalSession methodsFor:'accessing'!
 
 errStream
+    "the stdErrToStx stream.
+     Stuff written by the process' to its stderr will appear here"
+
     ^ errStream
 !
 
 inStream
+    "the stxTostdIn stream.
+     Stuff written to this stream will appear at the process' stdin"
+
     ^ inStream
 !
 
 outStream
+    "the process' stdOutToStx stream.
+     Stuff written by the process to its stdout will appear here"
+
     ^ outStream
 !
 
-pluggableCheckBeforeReadAction:something
-    pluggableCheckBeforeReadAction := something.
+pluggableCheckBeforeReadAction:aBlockOrNil
+    pluggableCheckBeforeReadAction := aBlockOrNil.
 !
 
-pluggableProcessInputAction:something
-    pluggableProcessInputAction := something.
+pluggableProcessInputAction:aBlockOrNil
+    pluggableProcessInputAction := aBlockOrNil.
 !
 
 pty
@@ -123,7 +134,7 @@
 !
 
 terminatedAction:aBlock
-    "hook to callback when terminated"
+    "hook to be called when terminated"
     
     terminatedAction := aBlock.
 
@@ -178,12 +189,12 @@
 !
 
 createTerminalConnectionAndSetupWith:setupBlock
-    "create a terminal conenction (pseudo terminal or pipe)"
+    "create a terminal connection (pseudo terminal or pipe)"
 
     |slaveFD master slave ptyTriple|
 
     OperatingSystem isMSWINDOWSlike ifTrue:[
-        "use two pipes to COMMAND.COM"
+        "use two pipes (eg. to COMMAND.COM)"
         stxToStdinPipe := NonPositionableExternalStream makePipe.
         stxToStdinPipe isNil ifTrue:[
             self error:(self class classResources string:'Could not create pipe to COMMAND.COM.') mayProceed:true. 
@@ -215,10 +226,11 @@
             ^ self.
         ].
 
+        "/ pty at:1 is the master;
+        "/ pty at:2 is the slave
+        "/ pty at:3 is the name of the pty
         ptyName := ptyTriple at:3.
 
-        "/ pty at:1 is the master;
-        "/ pty at:2 is the slave
         master := NonPositionableExternalStream forReadWriteToFileDescriptor:(ptyTriple at:1).
         master buffered:false.
 
@@ -235,6 +247,13 @@
     ].
 !
 
+isOpen
+    (inStream notNil and:[inStream isOpen]) ifTrue:[^ true].
+    (outStream notNil and:[outStream isOpen]) ifTrue:[^ true]. 
+    (errStream notNil and:[errStream isOpen]) ifTrue:[^ true]. 
+    ^ false
+!
+
 killShell
     "shut down my shell process and stop the background reader thread."
 
@@ -264,13 +283,13 @@
 !
 
 startCommand:aCommand in:aDirectory environment:envIn setupTerminalWith:setupBlock terminatedAction:terminatedActionArg
-    "start a command on a pseudo terminal. If the command arg is nil,
-     a shell is started. If aDirectory is not nil, the command is
-     executed in that directory.
-     Also fork a reader process, to read the shell's output and
-     tell me, whenever something arrives"
+    "start a command on a pseudo terminal. 
+     If the command arg is nil, a shell is started. 
+     If aDirectory is nil, the command is executed in the current directory.
+     Also fork a reader process, to read the shell's output 
+     and tell me, whenever something arrives"
 
-    |blocked exitStatus 
+    |exitStatus 
      cmd shell args env shellAndArgs didOpenTerminal|
 
     shellCommand := aCommand.
@@ -278,6 +297,9 @@
     terminatedAction := terminatedActionArg.
     didOpenTerminal := false.
 
+    env := Dictionary new.
+    env declareAllFrom:envIn.
+
     (inStream isNil or:[outStream isNil]) ifTrue:[
         self createTerminalConnectionAndSetupWith:setupBlock.
         didOpenTerminal := true.
@@ -298,15 +320,15 @@
             shell := '/bin/sh'.
             args := (Array with:'sh' with:'-c' with:aCommand).
         ].
-        env := Dictionary new.
-        env declareAllFrom:envIn.
         env at:'SHELL' put:shell.
     ].
 
-    blocked := OperatingSystem blockInterrupts.
-
     shellPid := Processor
                monitor:[
+                  Debug ifTrue:[
+                        Transcript show:'exec:'; show:shell.
+                        Transcript show:' '; showCR:args.
+                  ].
                   OperatingSystem
                       exec:shell
                       withArguments:args
@@ -332,10 +354,6 @@
                     ].
                ].
 
-    blocked ifFalse:[
-        OperatingSystem unblockInterrupts
-    ].
-
     "close the slave side of the pty/pipes (only used by the child)"
     pty notNil ifTrue:[
         (pty at:2) close.