How to read just a single character in shell script

In ksh you can basically do:

stty raw
REPLY=$(dd bs=1 count=1 2> /dev/null)
stty -raw

read -n1 works for bash

The stty raw mode prevents ctrl-c from working and can get you stuck in an input loop with no way out. Also the man page says stty -raw is not guaranteed to return your terminal to the same state.

So, building on dtmilano's answer using stty -icanon -echo avoids those issues.

#/bin/ksh
## /bin/{ksh,sh,zsh,...}

# read_char var
read_char() {
  stty -icanon -echo
  eval "$1=\$(dd bs=1 count=1 2>/dev/null)"
  stty icanon echo
}

read_char char
echo "got $char"

In bash, read can do it:

read -n1 ans