Command Capture

You can capture the output (stdout) of a command as a string using the notation \$( ) and then use that string in a variable assignment or as a command argument:

$ echo "The current date and time is: $(date)"
The current date and time is: Mon 19 Jun 2034 12:02:11 AM EDT

$ FILES="$(ls|wc -l)"
$ echo "There are $FILES files in the current directory $(pwd)"
There are 2938 files in the current directory /bin

Avoid Backticks! You may see old scripts that use backticks (reverse single quotes) for command capture, like this:

``  $ A=`ls` `

This is an archaic syntax which is depricated -- avoid doing this. Some fonts make it hard to distiguish between backticks and single-quotes, and nesting backticks is difficult.