Question

  # The **variable slicing** notation in the following conditional
  # needs some explanation: `${var#expr}` returns everything after
  # the match for 'expr' in the variable value (if any), and
  # `${var%expr}` returns everything that doesn't match (in this
  # case, just the very first character. You can also do this in
  # Bash with `${var:0:1}`, and you could use cut too: `cut -c1`.

what does this actually means?
can i get an example

Answer 1

Here’s an simple example:

#!/bin/bash

message="hello world!"
var1="hello"
var2="world!"
echo "${message#$var1}"
echo "${message%$var2}"
echo "${message%???}"
echo "${message}"

Output:

 world!
hello 
hello wor
hello world!