Re: why is eval needed?

[Ray Andrews <rayandrews@eastlink.ca>]

On 2022-11-19 06:43, Roman Perepelitsa wrote:
> With the default options this this the same as this:
>      tree '-L 2'
>
> Is it clear why it doesn't work?

Actually yes ... but that was only my last effort.  With double quotes 
the error is:

 >  -L 2 [error opening dir]

... and with no quotes it's:

 > test:local:5: not valid in this context: -L

... to correct myself, it's really the double quoted offering that I'd 
expect to work.  I'm pretty sure this is an invisible grouping of 
arguments but I don't know what to do about it other than 'eval'.  I'm 
thinking that when tree sees: " -L 2 " it's seeing that not as a switch 
followed by a number, but as a single syntactic element which it's 
trying to interpret as a directory name.  Which sorta is 
semi-understandable since the quotes make " -L 2 " into 'one thing' 
whereas tree want's it to be 'two things'.  How to drop that variable in 
there so that tree is happy with it?  Is this perhaps a bit of 
crabbiness on the part of tree?  Should " -L 2 " be an array?? Sheesh, 
that might keep tree happy.  And ...

     local level=( -L 2 )
     tree $level

...

Success!  Ha! You give me enough feedback that I can talk myself out of 
the problem :-)