I want to use user input of special characters in conditional statement. I tried:

read -p "press arrow up" foo
if [ $foo == "^[[A" ]; then echo yes; fi

It did not do what I wanted it to do.

  • 1
    You could do: if [ "$foo" = "$(xxd -r <<< "00000000: 1b5b 410a")" ];, but there might be a better option.
    – pLumo
    Jun 29 at 13:45
  • @pLumo Is there a map for all special characters for this format: (xxd -r <<< "00000000: 1b5b 410a"? Jun 29 at 13:48
  • 1
    No, I just made xxd <<< "$foo" and copy-pasted ;-)
    – pLumo
    Jun 29 at 13:48

2 Answers 2


In bash, you could use ANSI-C quoting


read -p "press arrow up " foo

if [ "$foo" = $'\e[A' ]; then
  echo 'yes'

For a more nuanced version, see BASH question: using read, can I capture a single char OR arrow key (on keyup)


Not especially beautiful, but you could compare hex values.

To find out hex value of up arrow, assign foo manually and run

xxd <<< "$foo"

Copy paste the output to your script and use xxd -r to revert the hex value:

up_arrow="$(xxd -r <<< "00000000: 1b5b 410a")"
if [ "$foo" = "$up_arrow" ]; then echo yes; fi

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