batch

#!/bin/sh

trap "" TERM

if [ $# -ne 1 ]
then
	cat <<-tac
		USAGE: $0 <filename>

		<filename> names a job list file, each line of which consists of a set of arguments to the driver script.

		NB: "arguments to the driver script" means you should NOT start the lines with '`dirname "$0"`/driver'!

		Note that, although this file may be modified while experiments are running, lines
		corresponding to completed or currently-running jobs should not be removed,
		reordered, or otherwise displaced in this case.  Such lines are identifiable by
		the progress comments automatically added at the end of their lines.
	tac
	exit 1
fi
file="$1"
set -e

confirm() {
	if [ $# -ne 2 ]
	then
		return 2
	fi
	local prompt="$1"
	local default="$2"
	set -e
	
	case "$default" in
	y)
		local suffix=" (Y/n)"
		;;
	n)
		local suffix=" (y/N)"
		;;
	*)
		false
		;;
	esac

	while true
	do
		printf %s "$prompt$suffix? "
		read response
		case "$response" in
		"")
			return "`[ "$default" = "y" ] && echo 0 || echo 1`"
			;;
		[yY])
			return 0
			;;
		[nN])
			return 1
			;;
		esac
	done
}

oneline() {
	if [ $# -lt 1 -o $# -gt 2 ]
	then
		return 1
	fi
	local linenum="$1"
	local mode="-n"
	local after=";p"
	if [ $# -eq 2 ]
	then
		mode="-i"
		after=""
		if [ -n "$2" ]
		then
			after=";s/$/ # $2/"
		fi
	fi
	set -e

	sed "$mode" "$linenum{s/ \?#.*//$after}" "$file"
}

timestamp() {
	date +"%F at %H:%M:%S %Z"
}

if [ ! -e "$file" ]
then
	echo "$file: No such batch file" >&2
	exit 2
fi

if grep "#" "$file" >/dev/null
then
	cat <<-tac
		+-----------------------------------------------------------------------------------------+
		|                                                                                         |
		| IMPORTANT: That batch queue already has commented lines, indicating that it may already |
		|            be running or have been run!  Please take a moment to confirm your intent:   |
		|                                                                                         |
		+-----------------------------------------------------------------------------------------+

	tac

	if confirm "Do you want to abort" y
	then
		exit 3
	elif confirm "Do you want me to remove all comments from the file" n
	then
		sed -i 's/ \?#.*//' "$file"
	fi
fi

cat <<-tac
	------------------------
	STARTING BATCH RUN FROM: $file
	------------------------

tac

line="1"
while [ "$line" -le "`wc -l "$file" | cut -d" " -f1`" ]
do
	args="`oneline "$line"`"
	cat <<-tac


		---------------------
		STARTING BATCH JOB $line: ./driver $args
		---------------------

	tac

	comment="launching"
	for time in `seq 3`
	do
		comment="$comment."
		oneline "$line" "$comment"
		sleep 2
	done

	oneline "$line" "running since `timestamp`"
	( trap - TERM && eval '"'"`dirname "$0"`/driver"'"' $args ) || true

	oneline "$line" "completed at `timestamp`"
	line="$((line + 1))"
done

cat <<-tac

	------------------------
	COMPLETED BATCH FUN RUN!
	------------------------
tac