add shellbat - script wrapper for tcl allowing call from sh/bash/tclsh or cmd.exe (.bat file) on windows and unix

src/modules/punk/mix/templates/utility/shellbat.txt

@@ -0,0 +1,106 @@
+if (true=="shellbat") #;#\
+: <<'HIDE_FROM_BASH_AND_SH'
+::lindex tcl;# leading colons hide from .bat, trailing slash hides next line from tcl \
+@call tclsh "%~dp0%~n0.bat" %*
+::lindex tcl;#\
+@set taskexitcode=%errorlevel% & goto :exit
+# -*- tcl -*-
+# #################################################################################################
+# This is a tcl shellbat file
+# It is tuned to run when called as a batch file, a tcl script, an sh script or a bash script,
+# so the specific layout and characters used are quite sensitive to change.
+# It can be called on unix or windows platforms with or without the interpreter being specified on the commandline.
+# e.g ./filename.sh.bat in sh or bash or powershell
+# e.g filename.sh or filename.sh.bat at windows command prompt
+# e.g tclsh filename.sh.bat |  sh filename.sh.bat  | bash filename.sh.bat
+# In all cases an arbitrary number of arguments are accepted
+# To avoid the initial commandline on stdout when calling as a batch file on windows, use:
+# cmd /Q /c filename.sh.bat
+# (because we cannot use @if to silence it, as this isn't understood by tcl,sh or bash)
+# #################################################################################################
+#fconfigure stdout -translation crlf
+# --- --- --- --- --- --- --- --- --- --- --- --- ---begin Tcl Payload
+#puts "script   : [info script]"
+#puts "argcount : $::argc"
+#puts "argvalues: $::argv"
+
+#<tcl-payload>
+
+# --- --- --- --- --- --- --- --- --- --- --- --- ---
+# only exit if needed. see exitcode notes at bottom of file and exit there for consistency across invocation methods
+# --- --- --- --- --- --- --- --- --- --- --- --- ---end Tcl Payload
+#--
+#-- bash/sh code follows. 
+#-- protect from tcl using line continuation char on the previous comment for each line, like so: \
+printf "etc"
+#-- or alternatively place sh/bash script within the false==false block
+#-- whilst being careful to balance braces {}
+#-- For more complex needs you should call out to external scripts
+#--
+#-- END marker for hide_from_bash_and_sh\
+HIDE_FROM_BASH_AND_SH
+#\
+then
+
+#---------------------------------------------------------
+if false==false # else { 
+then
+:
+#---------------------------------------------------------
+    #-- leave as is if all that's required is launching the Tcl payload"
+    #--
+    #-- Note that sh/bash script isn't called when running a .bat from cmd.exe on windows by default
+    #-- adjust line 4:  @call tclsh ...  to something like @call sh ... @call bash ..  or @call env sh ... etc as appropriate
+    #--   if sh/bash scripting needs to run on windows too.
+    #--
+    #printf "start of bash or sh code"
+    
+
+    #-- sh/bash launches Tcl here instead of shebang line at top
+
+    #-- use exec to use exitcode (if any) directly from the tcl script
+    exec /usr/bin/env tclsh "$0" "$@"
+    
+    #-- alternative - if sh/bash script required to run after the tcl call.
+    #/usr/bin/env tclsh "$0" "$@"
+    #tcl_exitcode=$?
+    #echo "tcl_exitcode: ${tcl_exitcode}"
+    
+    #-- override exitcode example
+    #exit 66
+    
+    #printf "No need for trailing slashes for sh/bash code here\n"
+#---------------------------------------------------------
+fi
+# }
+#---------------------------------------------------------
+
+#-- comment for line sample 1 with trailing continuation slash \
+#printf "tcl-invisible sh/bash line sample 1 \n"
+
+#-- comment for line sample 2 with trailing continuation slash \
+#printf "tcl-invisible sh/bash line sample 2 \n"
+
+
+#-- Consistent exitcode from sh,bash,tclsh or cmd
+#-- Call exit in tcl (or sh/bash) code only if explicitly required, otherwise leave this commented out.
+#-- (script might be more widely useable without explicit exit. e.g in tcl: set ::argc 1; set ::argv "val"; source filename.sh.bat )
+#-- exit line unprotected by trailing slash will work for tcl and/or sh/bash
+#exit 0 
+#exit 42
+
+
+#---------------------------------------------------------
+#-- end if true==shellbat on very first line\
+fi
+#---------------------------------------------------------
+
+#-- make sure sh/bash/tcl all skip over .bat style exit \
+: <<'shell_end'
+#-- .bat exit with exitcode from tcl process \
+:exit
+::lindex tcl;#\
+@exit /B %taskexitcode%
+#\
+shell_end
+