rc/sh/pause

#!/usr/bin/env sh
# YES_ZSH YES_BASH YES_DASH YES_ASH

### @ pause
### pause — the companion script of [`confirm`.](#confirm)
###
### ```
### $ pause
### Press any key to continue
### $ 
### ```

if [ -n "$ZSH_VERSION" ]; then
    pause() {
        [ $# -eq 0 ] || { printf "%s\n" "$0: too many arguments" >&2; return 2; }
        local c=
        read -sk $'?Press any key to continue\n' c
    }
elif [ -n "$BASH_VERSION" ]; then
    pause() {
        [ $# -eq 0 ] || { printf "%s\n" "$0: too many arguments" >&2; return 2; }
        local c=
        read -n1 -sp $'Press any key to continue\n' c 2>&1
    } 1<>/dev/tty <&1 # ensure this interacts with a terminal instead of a pipe
else
    pause() (
        [ $# -eq 0 ] || { printf "%s\n" "$0: too many arguments" >&2; return 2; }
        old="$(stty -g)"
        trap 'stty "$old"' INT EXIT
        printf 'Press any key to continue\n'
        stty -icanon -echo
        dd ibs=1 count=1 2>/dev/null >/dev/null
    ) 1<>/dev/tty <&1 # ensure this interacts with a terminal instead of a pipe
fi

[ -n "${preload+-}" ] || pause "$@"