Shell Programming and Scripting

Hi
I need to write a script that can check files in a folder one by one and compare against a fixed file.

i.e.
I have some files in folder_a
file1.txt
file2.txt
file3.txt
and a fixed file in folder_b
fixed.txt

Inside the fixed.txt, I have
line1.sql
line2.sql
line3.sql

Inside the file1.txt, I have
line1.sql
Inside the file2.txt, I have
line2.sql
Inside the file3.txt, I have
line3.sql

I was wondering, how can I write a script that would check file1.txt to file3.txt and make sure that fixed.txt has everthing in those three files?

I start by searching the files in folder_a like the following...then I am not sure what to do next

Code:

find ~/Documents/folder_a -name 'file*.txt'

Could someone please give me some guidence/help on how to go about solving this

Code:

for file in `ls folder_a`
do
cat $file | while read line
do
grep -q $line folder_b/fixed.txt
if [ $? -eq 1 ]; then
     echo "$file - $line not in fixed.txt"
     echo "$line" >> folder_b/fixed.txt
fi
done
done

I'm sure there are fancier ways, but something along those lines would get the job done.