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Tricky BASH quoting question

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# 8  
Old 04-06-2013
How about this:-

There is always a back door...

EDIT:
Remember! I am a mere amateur, I don't code for a living...

Code:
Last login: Sat Apr  6 16:21:32 on ttys000
Barrys-MacBook-Pro:~ barrywalker$ one="/Users/barrywalker/Desk*/"
Barrys-MacBook-Pro:~ barrywalker$ two="Empty Drawer/"
Barrys-MacBook-Pro:~ barrywalker$ three="1KH*"
Barrys-MacBook-Pro:~ barrywalker$ ls $one"$two"$three
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Function_Generator_OSX.py
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Function_Generator_OSX.py~
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Generator_OSX.py
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Generator_OSX.py~
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Wave.py
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Wave.py~
Barrys-MacBook-Pro:~ barrywalker$ > /tmp/txt
Barrys-MacBook-Pro:~ barrywalker$ ls $one"$two"$three >> /tmp/txt
Barrys-MacBook-Pro:~ barrywalker$ less /tmp/txt

Code:
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Function_Generator_OSX.py
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Function_Generator_OSX.py~
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Generator_OSX.py
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Generator_OSX.py~
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Wave.py
/Users/barrywalker/Desktop/Empty Drawer/1KHz_Sine_Wave.py~
/tmp/txt (END)

# 9  
Old 04-06-2013
@OP: Try:
Code:
 XML=$(<"$xmlLocation")

bash is the only shell where the quotes are is necessary in case the file name contains spaces for example..

In any other POSIX shell this should suffice:
Code:
XML=$(<$xmlLocation)

or at least:
Code:
XML=$(cat <$xmlLocation)

But
Code:
XML=$(cat "$xmlLocation")

There is a big difference between
Code:
"$xmlLocation"

and
Code:
$"xmlLocation"

--
Note:
To expand wildcards you could use a for loop for example..
Then you should be able to use one of the example above with the loop variable..

Code:
for file in blabla*/blabla
do
  printf "%s\n" "$file"
done

Last edited by Scrutinizer; 04-06-2013 at 03:37 PM..
# 10  
Old 04-06-2013
Quote:
Originally Posted by Scrutinizer
In any other POSIX shell this should suffice:
Code:
XML=$(<$xmlLocation)

That's a good point. Field splitting the word in a redirection operation not only violates POSIX, but it makes no sense (for the same reasons that field splitting is not performed on a variable assignment nor the word being tested by a case statement).

For the OP, here's a possible workaround. If space characters during field splitting are the only problem, the following should allow you to get passed it without using external commands or a subshell:
Code:
eval XML="\$(<${xmlLocation// /\\ })"

Regards,
Alister

---------- Post updated at 12:34 PM ---------- Previous update was at 12:31 PM ----------

And immediately after posting that, the following occurred to me. Duh!
Code:
IFS= XML=$(<$xmlLocation)

You may need to save the original IFS so that it can be restored afterwards.

Regards,
Alister
Last edited by alister; 04-06-2013 at 02:22 PM..
This User Gave Thanks to alister For This Post:
Michael Stora
# 11  
Old 04-06-2013
Please learn from the following exercise:
Code:
xmlLocation="two words"
echo 'blabla' >"$xmlLocation"99
read XML <"$xmlLocation"*
echo "$XML"

echo 'two
lines' >"$xmlLocation"99
XML=$(cat "$xmlLocation"*)
echo "$XML"

This User Gave Thanks to MadeInGermany For This Post:
wisecracker
# 12  
Old 04-06-2013
@MadeInGermany:
In dash, you will get:
Code:
cannot open two words*: No such file

Also, what happens (when the shell does happen to expand wildcards in the variable in the redirect and) "$xmlLocation"* would expand to more than one file? The first would render and ambiguous redirect and the second would concatenate the content of those files and put that in a variable.

IMO this is not the place to use wild cards. it would be more reliable for example to use a for loop to expand wildcards and then use use the loop variable with proper quoting..
# 13  
Old 04-07-2013
Hopfully I will have time to work on this project after next Wednesday. I think Allister's ideas are sound (I was wondeing about IFS= myself at dinner last night) but have not has access to that machine over the weekend to try them out.

I also remembered octal ASCII excaping and dreamed up the following at dinner. Have not had time to try it out yet.
Code:
xmlLocation="${xmlLocation// /\040}"
XML=$(<$xmlLocation)

Mike
Last edited by Michael Stora; 04-07-2013 at 01:48 AM..
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