A little code checker tool in python for Java,C,Cpp. Handles compile error, runtime error, accepted, wrong, TLE.

littlechecker.py

import os, filecmp

codes = {200:'success',404:'file not found',400:'error',408:'timeout'}

def compile(file,lang):
    if lang == 'java':
        class_file = file[:-4]+"class"
    elif lang == 'c':
        class_file = file[:-2]
    elif lang=='cpp':
        class_file = file[:-4]

    if (os.path.isfile(class_file)):
        os.remove(class_file)
    if (os.path.isfile(file)):
        if lang == 'java':
            os.system('javac '+file)
        elif lang == 'c' or lang == 'cpp':
            os.system('gcc -o '+class_file+' '+file)
        if (os.path.isfile(class_file)):
            return 200
        else:
            return 400
    else:
        return 404

def run(file,input,timeout,lang):
    if lang == 'java':
        cmd = 'java '+file
    elif lang=='c' or lang=='cpp':
        cmd = './'+file
    r = os.system('timeout '+timeout+' '+cmd+' < '+input+' > out.txt')
    if lang == 'java':
        os.remove(file+'.class')
    elif lang == 'c' or lang == 'cpp':
        os.remove(file)
    if r==0:
        return 200
    elif r==31744:
        os.remove('out.txt')
        return 408
    else:
        os.remove('out.txt')
        return 400

def match(output):
    if os.path.isfile('out.txt') and os.path.isfile(output):
        b = filecmp.cmp('out.txt',output)
        #os.remove('out.txt')
        return b
    else:
        return 404

file = 'add.c'
lang = 'c'
testin = 'testin.txt'
testout = 'testout.txt'
timeout = '1' # secs

print(codes[compile(file,'c')])
print (codes[run('add',testin,timeout,lang)])
print (match(testout))  # True implies that code is accepted.

Java,C,Cpp.
Handles compile error, runtime error, accepted, wrong, TLE.
Assumes all the files are in the same directory.

Hi Rajarsheem, I have updated your code to a more modular object oriented design. Also, regular expression have been used to replace the task of separating file extensions by hand. Here's a look
(https://gist.github.com/isopropylcyanide/fe6a02acad68656a08ddbd57d357cd00)

How do you integrate with java backend?

The only problem is that its not safe. The code may contain some dangerous function call that can affect the server.