From: E. Allaert
                                                           Date: 2001-10-02


             VLT-SW-OCT2001 - TCL/TK 8.3.3 PORTING GUIDELINES 
             ================================================

The upgrade from Tcl/Tk 8.0 to 8.3.3 does not introduce any incompatibilities
at the Tcl-code level. However, there are a few subtleties and obsolescent
features one may be confronted with:

1. the regular expression engine has been rewritten. Depending on how
   your patterns are coded (and special characters are escaped), you 
   may find in particular cases that Tcl/Tk 8.3.3 behaves somewhat
   differently from 8.0. Check the manpages of regexp(n)/regsub(n) and in 
   particular re_syntax(n), also to check out some powerful new features.

2. The shells "itclsh" and "itkwish" do no longer exist. Use the standart
   Tcl/Tk shells instead, and do a "package require Itcl".

3. The "-f" option in between the interpreter name and the Tcl-script
   filename (appearing e.g. within some sh-scripts as generated by 
   vltMakefile) was declared obsolescent quite some time ago. 
   Future versions of Tcl/Tk and seqWish actually can have problems if it
   is defined. Therefore, the "-f" should be removed from within scripts and
   Makefiles that produce executable Tcl scripts (see the "xxx_TCLSH" 
   definition in your module's Makefile).


In order to check your pre-OCT2001 Tcl/Tk scripts with regard to these Tcl/Tk
(and other) compatibility-issues, please do the following:

0. Get version 1.23 or higher of compat (which is anyway part of OCT2001; 
   so if you're running on a OCT2001 installation, compat should already be
   there for you, no need to cmmCopy). If it is not yet under VLTROOT, 
   install it in your INTROOT.

1. Read the manpage of compat 1.23.

2. cd to your module directory of the module to be checked, and run compat, 
   print results (or store them in a file)
   $ cd <module>
   $ find . -name "*.tcl" | compat -verbose \
	-configFile $INTROOT/config/compat.OCT2001.config | lp

3. Check the reported potential compatibilities within the files as
   listed by compat, and follow the instructions given by the verbose output.



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