Can alias pass parameters to FOR command?

[DOSforever]

alias a=echo %*
It work.
>a 1 2 3
1 2 3

alias b=`for %f in (%*) echo %f`
It doesn't work.
>b 1 2 3

output nothing.

 

[Charles Dye]

Try it with %$ instead of %*.

 

[DOSforever]

Try it with %$ instead of %*.

Oh yes. It work. Thank you!

 

[Charles Dye]

I'm not sure exactly what's going on here, but it has something to do with the parsing of parentheses:

C:\>alias b=`echo ( %* )`

C:\>b foo bar fum
(  ) foo bar fum

C:\>alias b=`echo ( %$ )`

C:\>b foo bar fum
( foo bar fum )

C:\>

But the help file only describes %$, not %*. I'm guessing %* is a spillover from batch files. If it works with aliases, it's only by accident. Anyway, that's my guess.

 

[DOSforever]

This has nothing to do with the parsing of parentheses. Even without parentheses, alias cannot recognize %*.

alias ta=`echo %* tail string`
c:\>ta head string
It will not display

head string tail string

Instead, it shows

tail string head string

Only alias ta=`echo %$ tail string` can correctly display

head string tail string

. In other words, alias completely treats %* as non-existent.

However, in the Help v.25 section 'Alias Parameters', it says:

Aliases can use command line parameters or parameters like those in batch files.

In the 'Batch File Parameters' section, the explanation for %$ and %* is:

%$ the complete command tail, modified by SHIFT
%* the complete command tail, unmodified by SHIFT

If alias could use parameters exactly the same way as batch files, then logically %* should also work, and the meaning of %* is not exactly the same as %$. For some reason, in practice, alias completely does not recognize %* , and the examples in the 'Alias Parameters' section do not mention the use of %* either.

 

[Charles Dye]

%$ expands to all alias parameters. %* expands to all batch parameters. They are analogous, but not the same thing. Note that you can use aliases in a batch file.

 

[Charles Dye]

@echo off
setlocal

alias test1=`echo "%$"`
alias test2=`echo "%*"`

echo These two aliases look similar, but they do very different things.
echo TEST1 echos ITS OWN parameters, in quotes:
echo.

test1 One two three

echo.
echo But TEST2 echos any BATCH FILE'S parameters, in quotes, followed
echo by its own, if any:
echo.

test2 One two three

echo.
echo Try calling this batch files with different parameters to see how
echo this works.
echo.

endlocal

 

[vefatica]

Batch files suffer a bit also when it comes to %*.

 

[vefatica]

The only thing I found is that %* is not recognized as a "whole" variable. That is, if you echo **%***, you get *****. Are there other shortcomings?

And %* wouldn't enhance aliases any since SHIFT is not valid in an alias.

 

[vefatica]

P.S., but you can %[*].

v:\> type params.btm
echo ..%*..
echo ..%[*]..

v:\> params.btm a b c
..*..
..a b c..

 

[AnrDaemon]

Documentation clearly states that %* is a CMD compatibility and will always expand to all batch parameters.

 

[Jay Sage]

There is another difference I discovered. The variable %$ parses the arguments, while %* returns the command tail as entered by the user. Among other things, multiple spaces between arguments condense into single spaces. Here is some of the output from a BTM script VARS.BTM that I wrote to display the values of many batch file parameters. Here it was invoked as vars one two, with three spaces separating the two arguments.

   %$                 All arguments on command line (as per TCC) .............. one two
   %$                 All arguments on command line (as per TCC) ASCII ........ 111 110 101 32 116 119 111
   %*                 Complete command tail ................................... one   two
   %*                 Complete command tail (all characters) ASCII ............ 111 110 101 32 32 32 116 119 111

There is a bigger difference when arguments are separated by commas, as shown with vars a,b. In one case, commas are stripped and replaced by spaces. As in the above example, %* returns the command tail exactly as the user entered it.

   %$                 All arguments on command line (as per TCC) .............. a b
   %$                 All arguments on command line (as per TCC) ASCII ........ 97 32 98
   %*                 Complete command tail ................................... a,b
   %*                 Complete command tail (all characters) ASCII ............ 97 44 98

 

[Jay Sage]

The TCC help files should be corrected. The parameter "%*" really is the "complete command tail, unmodified by SHIFT". The parameter "%$", however, is not the "complete command tail, modified by SHIFT". It is the "complete command tail, modified by SHIFT and with multiple parameter separators condensed to a single space".

For example, if the command tail is one, ,two, then %$ is one two, and %* is one, ,two.

 

[Jay Sage]

Slight addition: "%*" is also not exactly the command tail. It strips leading and trailing parameter separators, including commas. Thus a command tail of , one two becomes one two.