Calling linux utilities with options from within a Bash script.

Question

This is my first Bash script so forgive me if this question is trivial. I need to count the number of files within a specified directory $HOME/.junk. I thought this would be simple and assumed the following would work:

numfiles= find $HOME/.junk -type f | wc -l
echo "There are $numfiles files in the .junk directory."

Typing find $HOME/.junk -type f | wc -l at the command line works exactly how I expected it to, simply returning the number of files. Why is this not working when it is entered within my script? Am I missing some special notation when it comes to passing options to the utilities?

Thank you very much for your time and help.

Answer 1

You just need to surround it with backticks:

numfiles=`find $HOME/.junk -type f | wc -l`

The term for this is command substitution.

Answer 2

if you are using bash you can also use $() for command substitution, like so:

numfiles=$(find $HOME/.junk -type f | wc -l)

I find this to be slightly more readable than backquotes, as well as having the ability to nest several commands inside one another.

Answer 3

with bash 4 (if you want recursive)

#!/bin/bash
shopt -s globstar
for file in **
do
 ((i++))
done
echo "total files: $i"

if not

#!/bin/bash
shopt -s dotglob
shopt -s nullglob
for file in *
do 
  ((i++))
done 
echo "total files: $i"