Shell Programming and Scripting

Okie I have two files.

file1 with input

asdf_s45
fdsa_s20
jkl_s32
lkj_s3

and file2 with input

asdf_s44
fdsa_s19
jkl_s31
lkj_s2

now I have counted the total number of lines in the file and put it in a variable so num_lines=4

now I have a while loop to repeat a diff command for each line from each file and print it out so:
x=1

while ((x<$num_lines)) ; do
sed '$xq;d' file1 > final_file1
sed '$xq;d' file2 > final_file2

read final1 < final_file1
read final2 < final_file2
diff $final1 $final2 > final_difference
((x=x+1))
done
exit 0

This will not allow $x to be a number in the sed command.. need help..

Variables in single quotes do not get expanded. You need to use double quotes.

okie got it, line
"sed '$xq;d' file1>final_file1"
should be
"sed "$xq;d" file1>final_file1"

now Im trying to do a diff of the variables and place it into a file
final_difference$x for each line diffed.. somehow it is not working though..is something wrong with my while loop?

okie got that fixed lol.. problem was
the line was supposed to be
"sed "${x}q;d" file1>final_file1"

after that I had to change the diff line to

"diff $file1 $file2>>final_difference"

now I just need to figure out how to put a title to each new diff file to show separation. anyone?

You mean unique file name for each new diff file? Why not use this precious $x variable you have anyway?

actually a new start title for each diff entry (sorrie not keeping it in separate files)

so what I tried to do was

x=1

while ((x<$num_lines)) ; do
sed "${x}q;d" file1 > final_file1
sed "${x}q;d" file2 > final_file2

read final1 < final_file1
read final2 < final_file2

echo "Differences between " $final1 " and " $final2 >>final_difference
diff $final1 $final2 >> final_difference
((x=x+1))
done
exit 0

and it does add a title on the top of each difference but then gives gibberish at the end for files that did not have a diff..

You could compare them or look for a zero-sized file or otherwise think of a condition to avoid that when there is no difference.