grade_utils

#!/bin/bash
# Utilities for making grade-scripts shorter

set -o pipefail   # see https://unix.stackexchange.com/a/267031/16569
exec 2>&1         # redirect stderr to stdout: https://unix.stackexchange.com/q/505581/16569


# from here: https://stackoverflow.com/a/1115909/827927
swap() {
    local TMPFILE=tmp.$$
	if [ -f $1 ] && [ -f $2 ]
	then
    	mv $1 $TMPFILE && mv $2 $1 && mv $TMPFILE $2
	elif [ -f $1 ]
	then
    	mv $1 $2
	elif [ -f $2 ]
	then
    	mv $2 $1
	fi
}

# A function that echoes and executes a command.
call() { 
	echo "! ${@/eval/}" 
	$@
}

# A function that echoes and executes a command.
# If it fails, it sets grade=0.
# If it succeeds, it sets grade=100.
grade_command() { 
	grade=100
	call $@
	exitcode=$?
	if [ $exitcode -ne 0 ]
	then 
		printf "*** Command failed. Exit code: $exitcode ***\n"
		grade=0
	fi
}

# A function that echoes and executes a command.
# If it fails, it sets grade=0.
# If it succeeds, it sets grade=[last line of output]
grade_program() { 
	program=$1
	TIMEOUT=1
	echo "! timeout $TIMEOUT ./$program" 
	timeout $TIMEOUT ./$program
	exitcode=$?
	if [ $exitcode -ne 0 ]
	then 
		printf "*** Command failed. Exit code: $exitcode ***\n"
		grade=0
	else
		grade=$( { timeout $TIMEOUT ./$program || echo 0; } | tail -n1 )
	fi
}