Bash: Check if enter was pressed

问题

How can I check in Bash if the Enter key has been pressed? I'm using the read command:

read -p "Please press ENTER" var

回答1:

Firstly, check whether the exit status is normal ($? should be 0).

Secondly, check that $var equals "".

回答2:

You can also check the length of the $var variable after it was set by the read call. If it's 0, the user just hit enter without typing anything else:

read -p "Please press ENTER" var
if [ ${#var} -eq 0 ]; then
  echo "Enter was hit"
fi

回答3:

try this:

read var

echo $REPLY|hexdump -C

来源：https://stackoverflow.com/questions/10385782/bash-check-if-enter-was-pressed