Hiding subroutine arguments to preserve the conventional arguments string

[frank.w...@gmail.com]

:: BEGIN SCRIPT :::::::::::::::::::::::::::::::::::::::::::::::::::::
:: hiddenArguments.cmd
:: From the desk of Frank P. Westlake, 2013-04-23
:: Written on Windows 8.
@Goto :main

REMARKS
I submitted something like this a few years ago and I don't think I used
it again until this week. This technique is not often necessary but it
can greatly simplify command line parsing in some cases. Arguments are
attached to the subroutine label by separating them from it and from
each other with a colon (:subroutine_name:arg1:arg2). The second colon
terminates the label for use with CALL and GOTO but the entire string
gets stuffed into "%0" for the subroutine. Normal command line
parameters (%1-%9) don't begin until the first command line delimiter
(, ;=).

The script first demonstrates with the subroutine ":tutorial" how to get
the arguments from the label. It uses a command line which shows which
cahracters can be used and how they must be handled. The wild card
characters '*' and '?' can be passed and used but not by the technique
used in this subroutine; they require parsing with 'FOR /F' which either
causes the loss of any colons in the arguments or prohibits having
quoted arguments.

Next the script uses the subroutine ":usage_demo" to perform a very
simple task which wants the switches separate from the string contained
in '%*'. It does not do all the parsing which is done by ":tutorial"
because it is not all necessary for this simple task.

Frank

:main
@Echo OFF
SetLocal EnableExtensions DisableDelayedExpansion
REM NOT ALLOWED: & | < > !
Call :tutorial:"Quoted =,;:()":Unquoted~`@#$_-+{}[]\'/.:"Two carets=^^":"Four percents=%%%%":"Wild cards not permitted." Conventional command line arguments.
Echo Usage demo:
Call :usage_demo:/I:/N String to find.
Goto :EOF

:usage_demo
SetLocal EnableExtensions EnableDelayedExpansion
Set "params="
Set "$*=%0" & Set "$*=!$*:~1!" & Set "$*=!$*:*:=!"
Set "$*=!$*::= _THIS_SPACE_WAS_A_COLON_ !"
For %%a in (!$*!) Do (
If "_THIS_SPACE_WAS_A_COLON_" NEQ "%%a" (
Set "$=%%~a"
Set "params=!params! !$: _THIS_SPACE_WAS_A_COLON_ =:!"
)
)
FindStr %params% /C:"%*" "%~f0"
Goto :EOF

:tutorial
SetLocal EnableExtensions EnableDelayedExpansion
Set /A "$#=-1"
Set "$*="
Set "$=%0"
Set "$=%$::= _THIS_SPACE_WAS_A_COLON_ %"
For %%a in (%$%) Do (
If "_THIS_SPACE_WAS_A_COLON_" NEQ "%%a" (
Set /A "$#+=1"
Set "$=%%~a"
Set "$!$#!=!$: _THIS_SPACE_WAS_A_COLON_ =:!"
Set $*=!$*! "!$: _THIS_SPACE_WAS_A_COLON_ =:!"
)
)
Set "$="
Echo;$*=!$*!
Echo;$#=!$#!
For /L %%i in (0,1,!$#!) Do Echo;$%%i=!$%%i!
Echo %%*=%*
Echo;
Echo;LEGEND
Echo; $# The number of parameters not including the subroutine name ($0).
Echo; $* All hidden arguments separately quoted and concatenated with space.
Echo; $0 The subroutine name.
Echo; $1+ Arguments 1 through %%$#%%.
Echo; %%* The conventional command line argument string.
Echo;
Goto :EOF
:: END SCRIPT ::::::::::::::::::::::::::::::::::::::::::::::::::::

[Frank Westlake]

Here's an example of using FOR/F to get an expected argument. This can
be added to the previous demo script.

:main
Echo String length demo:
Call :strlen:length Find the length of this string.
Echo Length of "Find the length of this string." is %length% characters.
Goto :EOF

:strlen:<variable name> <string>
For /F "tokens=2 delims=:" %%a in ("%0") Do (
For /F "delims=:" %%b in (
'(Echo;%*^& Echo.NEXT LINE^)^|FindStr /O "NEXT LINE"'
) Do Set /A "%%~a=%%b-3"
)
Goto :EOF

Frank

[jeb]

Btw. There exists a strange behaviour with CALL to labels

@echo off
setlocal EnableDelayedExpansion
call :label:one p1 p2

set var=label:one
set "pVar=:^!var^!"
call !pVar!:two P1 P2

set "complex^" var%%^^^^x=label:three"
set "pVar=:^!complex^^" var%%%%^^^^x^^!"
call !pVar!:four P1 P2
exit /b

:label
setlocal DisableDelayedExpansion
echo on
rem :label is called with '%0' Parameters are '%*'
@echo off
exit /b
------------------------
Output:
C:\temp>rem :label is called with ':label:one' Parameters are 'p1 p2'

C:\temp>rem :label is called with ':!var!:two' Parameters are 'P1 P2'

C:\temp>rem :label is called with ':!complex^" var%^^x!:four P1 P2' Parameters are ''
-------------------------

As you can see the delayed expansion is expanded twice, but the result of the second expansion is only used for the call, but in %0 is still the unexpanded value.
So even the beginning of %0 can be different to the name of the label

jeb

[frank.w...@gmail.com]

From jeb :

>Output:
>C:\temp>rem :label is called with ':label:one'
>Parameters are 'p1 p2'

>C:\temp>rem :label is called with ':!var!:two'
>Parameters are 'P1 P2'

>C:\temp>rem :label is called with ':!complex^"
>var%^^x!:four P1 P2' Parameters are ''
>-------------------------

The output on my system is thus:

The syntax of the command is incorrect.
The syntax of the command is incorrect.
The system cannot find the batch label specified - EOF

If I modify your script to use command extensions then
it produces the output you showed.

Frank