Alias expansion and switch character

  • This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
May 30, 2008
209
1
#1
Using build 151.

Should alias expansion cause an extra space to be inserted before switch (/) characters used in the alias parameters given when invoking the alias?

It seems to do that with this alias:

alias cpfrom=*copy /G ftp:%1 %2

c:\> cpfrom putget/idoc.zip

After expansion with Ctrl-F:

c:\> copy /G ftp:putget /idoc.zip

Note the extra space after "putget".

Needless to say, this causes the command to fail.
A simple work-around is to use `cpfrom "putget/idoc.zip"` instead.

Defining the alias as

alias cpfrom=*copy /G "ftp:%1" %2

does not help.

Is this behaviour deliberate or might it be a bug in the alias expansion handling?

Might there be a way to define the alias so that `cpfrom putget/idoc.zip` works "as expected"?

--
Niklas Bäckman
 

Charles Dye

Super Moderator
Staff member
May 20, 2008
3,410
40
Albuquerque, NM
prospero.unm.edu
#2
Should alias expansion cause an extra space to be inserted before switch (/) characters used in the alias parameters given when invoking the alias?

It seems to do that with this alias:

alias cpfrom=*copy /G ftp:%1 %2

c:\> cpfrom putget/idoc.zip

After expansion with Ctrl-F:

c:\> copy /G ftp:putget /idoc.zip

Note the extra space after "putget".
The "extra" space is in your alias definition, between the %1 and the %2. If you don't want PUTGET and /IDOC.ZIP to be treated as two separate parameters, then quoting the entire string is the correct way to do that.
 
#3
nikbackm wrote:
| Using build 151.
|
| Should alias expansion cause an extra space to be inserted before
| switch (/) characters used in the alias parameters given when
| invoking the alias?
|
| It seems to do that with this alias:
|
| alias cpfrom=*copy /G ftp:%1 %2

I presume you did not use the above command as displayed when defining the
alias CPFROM, as it would have expanded %1 and %2 during definition,
resulting in


> which cpfrom
cpfrom is an alias: *copy /G ftp:

With this definition of CPFROM, I get different result:


>cpfrom putget/idoc.zip [ctrl-F]
>copy /G ftp: putget/idoc.zip
Note the extra space BEFORE "putget". This is exactly what I would expect.

I then tried

alias cpfrom=`*copy /G ftp:%1 %2`

Now entering


>cpfrom putget/idoc.zip [ctrl-F]
>copy /G ftp:putget /idoc.zip
as in the OP.

Entering


>cpfrom "putget/idoc.zip" [ctrl-F]
>copy /G ftp:"putget/idoc.zip"
as expected, but it's wrong syntax!

The problem is that / is parsed as a parameter separator. I have not come up
with a variant alias to perform according to the perceived intent of the OP.

Another problem is that if COPY is an alias, the alias expansion replaces
*COPY with COPY, thus executing the command will use the value of the alias
COPY, not the internal command COPY. This is definitely a parser error, or
at least a limitation of the alias expansion logic triggered by ctrl-F.

What I don't know is what the command actually built by the parser without
the expansion actually looks like.