Re: [vox-tech] shell question

[Micah Cowan <micahMAPS@cowanbox.com>]

On Thu, Nov 02, 2000 at 09:09:56AM -0800, Peter Jay Salzman wrote:
> consider the following directory:
> 
>       % ls
>       A 1st file  A 3rd file  A 5th file  A 7th file
>       A 2nd file  A 4th file  A 6th file
> 
> i don't understand what's going on here; spaces in the filename seem to
> delineate the end of the file, according to the following script.  i trust
> echo.  the problem must be `ls`.
> 
>       % for i in `ls`; do echo $i; done
>       A
>       1st
>       file
>       A
>       2nd
>       file
>       A
>       3rd
>       ...  (etc)
> 
> 

I can explain why.  The backticks gets the literal output of ls, which is
then used as a list in for.  Once the output is received, bash has no way
of knowing which spaces are part of the filename - all it knows is it has
a bunch of words seperated by spaces.  This is not a bug in echo, ls, or
bash - it's just slightly incorrect usage.

What *will* work is:

$ for i in *; do echo $; done.

Because this returns a bash glob-spawned list, which will produce the literal
filenames, and it will work correctly because bash isn't forced to seperate
tokens - it gets them already seperated.

Hope that helps!

BTW, using '%' for the prompt is usually a csh thing - as you seem
to be talking about bash flow control structures, etc., you should
probably use '$'.

Micah