Purpose: to collect information regarding special tips, techniques, tricks, and got-chas in writing '''true''' cross platform Tcl scripts.

Page begun by [Larry Virden].

See also [Tcl built-ins for cross platform functionality].
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Issues:

   * Directory naming conventions differ somewhat between Unix, Windows, MacOS.

   * Line endings on text based disk files vary.

   * Command pipelines are not supported on some platforms.

   * [How do I manage lock files in a cross platform manner in Tcl]?

   * [Practical Guide to Choosing Fonts]

   * [What about time epoch differences]?

   * [Tcl built-ins for cross platform functionality]

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Other resources:

   * Tcl Engineering White Paper ftp://ftp.scriptics.com/pub/tcl/doc/engManual.tar.Z
   * Tcl Style Guide ftp://ftp.scriptics.com/pub/tcl/doc/styleGuide.tar.gz
   * Tcl portability White Paper ftp://ftp.scriptics.com/pub/tcl/doc/portable-tk.ps (I think)

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Here are some example Tcl applications that run on all of UNIX, Win, and MacOS and which are not merely trivial but demonstrate many of the problems/solutions of cross-platform portability.

   * Alphatk [http://www.santafe.edu/~vince/Alphatk.html] is such an application.  It is a cross-platform programmer's editor.  It has some problems on MacOS, but this is due to a few remaining bugs/issues in MacTk, and not in Alphatk's scripts.  It has cross-platform support for things like: executing external scripts, starting up latex processes (and capturing their output), etc.  There are now about 170000 lines of Tcl code in there, which work cross-platform!

   * tkbiff [http://expect.nist.gov/tkbiff] includes a lot of code to make it work on all platforms.  It sounds like a trivial app but it is actually 4300 lines of Tcl.  Besides the things Tcl handles automatically, extra coding is necessary for cross-platform issues like : playing audios, fonts, cursors, preference file locations, keyboard/mouse bindings, invoking browsers, dialogues, and diagnostics.  Fairly good rosetta stone since it is small and yet demonstrates things like UNIX/Win exec vs Mac-Applescript and Mac-resources.

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Sometimes, even when a command itself isn't available in Tcl or Tk, it
can be built rather easily.  Hopefully the maintainer of [tcllib] and
developers will continue to work together to gather things like [fileutil]
and other pieces of code together into modules.
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Please feel free to add anything you can.  Hopefully some new tools could be added to the Tcl and Tk core to improve portability!