#!/bin/bash
#
# Present a list of shell commands by single-stepping and echoing commands.
# Note that this only works well for self-contained single lines, no multi-line
# loops etc.
#
# (c) 2009 Martin Pitt <martin@piware.de>
# License: Public Domain

NORMAL=""
BOLD=";1"
STATE=$NORMAL

OFF=0
RED=31$STATE
GREEN=32$STATE
YELLOW=33$STATE
BLUE=34$STATE
MAGENTA=35$STATE
CYAN=36$STATE

# Presentation colors
COMMENT=$GREEN
PROMPT=$RED
CMD=$BLUE
OUTPUT=$OFF

if [ "x$1" = 'x--dark' ]; then
    shift || true
    STATE=$BOLD
    CMD=$YELLOW
fi

[ -e "$1" ] || {
    echo "Usage: $0 [--dark] <shell script>" >&2
    exit 1
}

clear
echo -en "\e[${PROMPT}m\$\e[${CMD}m "

while read line; do
    # paragraph clears screen
    if [ -z "$line" ]; then
	clear
	echo -en "\e[${PROMPT}m\$\e[${CMD}m "
	continue
    fi

    # comment
    if [ "${line:0:1}" = "#" ]; then
	if [ -n "${line:1}" ]; then
	    echo -e "\r\e[${COMMENT}m$line\e[${CMD}m"
	    echo -en "\e[${PROMPT}m\$\e[${CMD}m "
	fi
	continue
    fi

    # execute command
    echo -n "$line"
    read < /dev/tty
    echo -ne "\e[${OUTPUT}m"
    eval "$line"
    echo -en "\n\e[${PROMPT}m\$\e[${CMD}m "
    read -s < /dev/tty
done < "$1"