Why doesn't this bit of code work? Setting variables and config file

Question

I have recently just made this script:

 if test -s $HOME/koolaid.txt ; then
  Billz=$(grep / $HOME/koolaid.txt)
  echo $Billz
  else
 Billz=$HOME/notkoolaid
 echo $Billz
 fi



 if test -d $Billz ; then
  echo "Ok"
 else touch $Billz
fi

So basically, if the file $HOME/koolaid.txt file does NOT exist, then Billz will be set as $HOME/koolaid.txt. It then sucesfully creates the file.

However, if I do make the koolaid.txt then I get this

mkdir: cannot create directory : No such file or directory

Any help would be appreciated

-1 for putting garbage in my eyes. I will not doing efforts to understand what's wrong here while you don't take the small time to read your post before submit it. — Gilles Quénot, Jun 20 '13 at 19:57
You may find [Tilde expansion in quotes](http://stackoverflow.com/questions/15858766/tilde-expansion-in-quotes/15859646#15859646) useful and relevant. — Jonathan Leffler, Jun 20 '13 at 21:19
I the question was unable to be answered, why are there two answers with one accepted? — SethMMorton, Jun 21 '13 at 03:19

clt60 · Accepted Answer · 2013-06-20T21:09:11.427

1

Here is a difference between content of a variable and evaluated content... if your variable contains a string $HOME/some - you need expand it to get /home/login/same One dangerous method is eval.

bin=$(grep / ~/.rm.cfg)
eval rbin=${bin:-$HOME/deleted}
echo "==$rbin=="

Don't eval unless you're absolutely sure what you evaling...

edited Jun 20 '13 at 21:09

answered Jun 20 '13 at 20:28

clt60

62,119
17
107
194

I still don't understand why my command doesn't work. I would rather not meddle around in eval for now, especially as I am beginner and as you said it can be dangerous? – DeaIss Jun 20 '13 at 21:04
1

@oOTesterOo because the **string** `$HOME` need to be expanded... see my (working) example.. – clt60 Jun 20 '13 at 21:10

score 0 · Answer 2 · answered Jun 20 '13 at 20:00

0

Here are a couple things to fix:

Start your script with a "shebang," such as:

#!/bin/sh

This way the shell will know that you want to run this as a Bourne shell script.

Also, your conditional at the top of the script doesn't handle the case well in which .rm.cfg exists but doesn't contain a slash character anywhere in it. In that case the rbin variable never gets set.

Finally, try adding the line

ls ~

at the top so you can see how the shell is interpreting the tilde character; that might be the problem.

answered Jun 20 '13 at 20:00

catfood

4,267
5
29
55

Thanks for the quickly reply! I have added the shebang line now. Also, I am assuming that it DOES have the slash character for now. I will try and make this line more specific later, but for now it just seems that it wont even create the directory I want once the variable has been changed. I still can't find the problem – DeaIss Jun 20 '13 at 20:07
1

What happens with "ls ~" in the script? Is ~ doing what you expect it to? – catfood Jun 20 '13 at 21:10

Why doesn't this bit of code work? Setting variables and config file

2 Answers2