How can I read a single line from a text file using bash?

[Euclid]

I want to write a script that will automatically backup my documents to a remote computer. I have a lot (~500 MB) of files, so I only want the files to be backed up when a newer version exists.

Short version of the question: how do I read a single line from a text file using bash?

Long version of the question:
Here is the plan for the script...

#!/bin/bash
ssh remoteComputer # connect to remote comp
find ~/Documents * > files.txt #find all files in documents and write to files.txt
line=1
fileLength = (number of lines if files.txt)
while [line -lte fileLength]
do
(put filename at the lineth line to the string fileName)
if fileName -nt remoteComputer:~/Documents/fileName
#go through all files and
#check to see if remoteComputer has the
#latest version of this file already
scp line to remoteComputer
#if so, update file
fi
line=$[$line+1]
done
exit #leave ssh session

The exact implementation is what I need help on. If I could read files.txt line by line this would be very easy, but I can't figure it out!

 

[mgb_phys]

You should look at rsync, it not only does this but can copy just the parts of files that have changed.

 

[Euclid]

That's just too easy! Thanks mgb_phys!