commands for bash script that handles files of varying number of lines
 

Need commands for bash schell script that handles files varying in number of lines.

You can use wc to get the number of lines in a file (the option -l does this). Edit: you can also store the output of a command in a variable with syntax like this:

variable=`command`

For example, to put the number of lines in the file foo in a variable called num_lines, you'd use the following:

num_lines=`wc -l foo`