Differences include: * event loop * various memory usage patterns * GUI service Under DOS, tclsh myscript.tcl > output.txt does what one wants, but it's harder to achieve with [wish]. [Luciano ES] ''Harder? Harder how?'' (please read on...) ---- This topic was raised at [comp.lang.tcl] by [Luciano ES] who asked, boldly: "What do we need [tclsh] for?" My point was that ''[wish] can do everything that [tclsh] can, plus the extra optional features, so why not ditch [tclsh] and keep [wish] only?'' Among the several mentioned reasons, were: * tclsh does not require a graphics server, like [X]. Also, tclsh uses a lot less resources than wish; * many applications that rely on [Tcl]/[Tk] are run on very low-spec hardware; * many (most?) applications do not need a GUI at all; * ''under Windows, tclsh has a console associated with it and it's the only way to see the various printf messages your code has under Windows''; * Tcl makes very frequent use of event loops, which under Tk results in a probably unwelcome blank window being shown; * ''after processing a script, tclsh exits, while wish hangs around, entering the event loop''; * [LV] adds: ''The very act of starting a wish begins by attempting to create and display a toplevel widget. For historical reasons, Tk has always created and instantiated a toplevel.'' It was also noted that the opposite is a lot easier to achieve, i.e. ditch wish and keep tclsh. package require Tk 8.4 The simple line above in a Tcl script, even if run by [tclsh], will immediately make all [Tk] functionality available throughout the rest of the program. A little (just a little) more about that is discussed in [Using Tk as a loadable package]. ---- Someone also added that: "''At a [DOS] prompt I can say... '' tclsh myscript.tcl >output.txt ''... to capture the output (of practically unlimited size). Using wish for this kind of stuff might be possible but would be more involved IMO.''" The information was confirmed by a notorious Tcl expert, who also said that "''[Tkcon] would require an [exec] at the beginning of that command''" But it still puzzles me: wm withdraw . puts "hi, Mom" exit The script above can be run by wish and produce the same result as tclsh. wish myscript.tcl >output.txt in a [DOS] prompt produces just the same result as... tclsh myscript.tcl >output.txt I also ran '''wish myscript.tcl >output.txt''' from [Tkcon], without the [exec] command, and had exactly the same result (shrug). So, my conclusions so far are: * if I use wish instead of tclsh, I have to use [wm withdraw] . if I don't want any windows, and [exit] because [wish] won't [exit] automatically like [tclsh]; * [wish] uses up more resources than [tclsh], and that is often not good; * if there is no $DISPLAY environment variable available, [wish] refuses to initialize, but that is hard-coded and I wonder if it could be changed. [[ [CL] notes that "[Image manipulation without Tk]", which now appears just confusing, has fragments of an explanation that bears on this topic.]] Note that I don't really want to get rid of tclsh. It is all just for the sake of getting a better grasp of the differences between the two programs. ---- [SLB] From a DOS prompt try running wish myscript.tcl i.e. with no redirection. The output will be lost. Conversely, if you setup file extensions so you can run Tcl scripts from Windows Explorer via tclsh, you will get a DOS Window. [RLH] You will not get the DOS Window if you require the Tk package in your Tcl script. Even after reading all of this I come away with "we only really need tclsh now.". Am I missing something? package require Tk 8.4 [SLB] Hmm, not what I see. Let's be specific. I'm running ActiveTcl 8.4.5 on Windows 2000. If I use the Run option from the start menu to launch tclsh84 I get a DOS window. I can use package require Tk 8.4 and the DOS window is still there. I try the console command and it says: invalid command name "console" So the wish console is not available from tclsh. That's one difference between wish and tclsh If I now take a simple Tcl script such as: package require Tk button .b pack .b save it in a file and double click on the file from Windows Explorer, then the wish top level window appears with no DOS window. Perhaps this is what you meant? But now, I go to Windows Explorer's Tools menu, select Folder Options and then choose the File Types tab. I locate the file type Tcl and press Advanced to see its actions. I choose action 'open' and press Edit... This reveals that 'open' uses wish84. Change it to tclsh84, OK all the dialogs and try running the script again. I now see DOS prompt. ---- [category internals]