-d option not working. . .?

[Michael Williams]

Hi All,

I've got a script that I'm trying to set up, but it keeps telling me  
that  "[-d command not found".  Can someone please explain what is  
wrong with this?:





#!/bin/sh

for i in $*
do
{
if  [-d $i]
then
echo "$i is a directory! Yay!"
else
echo "$i is not a directory!"
fi
}
done



Regards,
Michael

Re: -d option not working. . .?

[Michael Williams]

On Sep 12, 2007, at 2:56 AM, Bob Proulx wrote:

 The [ is a shell builtin, not a shell
metacharacter.  Shell metacharacters do not need to be separated by
whitespace but the test program needs to be apart or it won't be
parsed right.  That is why you are seeing "[-d" not found.  It is not
a parenthesis as in some programming languages.  The [ is a synonym
for the "test" operator.  It is a command like grep, sed, awk, etc.



Being that I'm not a bash (or any other shell for that matter) guru,  
is there any reason that parsing occurs this way?  Why is it not more  
like other programming languages?



  [ -d /tmp ] && echo /tmp is a dir

Do it this way.

  if [ -d "$i" ]

Note that you should quote the argument to protect against whitespace
there.


Thanks, that worked perfectly!

Re: -d option not working. . .?

[Michael Williams]

Two words: history and POSIX.  It's been done that way for more  
than 20
years, so it was standardized that way.  Changing it would break  
too many

existing scripts.



Forgive me for saying so, and please appreciate both the sarcasm and  
irony, but I've never been one for "that's the way it's always  
been".  I mean, if we all thought that way, we'd be a bunch of  
bloodletting flat-earthers. . .no?  ;)


That said, I'm sure these BASH and POSIX guys were (and still are) a  
lot smarter than myself.  So I'll rest my faith on that and see about  
doing a bit more getting familiar.


Best Regards All!

Michael