Mini Online Judge script - 22/11/2011

compiler.php

<?php
/**
 *	My mini online judge script in php. This was done as a part of 6 hour hackathon.
 *
 *	@author	Ashwanth Kumar
 *	@version 0.1
 *	@date 22/11/2011
 **/
/**
	There are things to note here as,
	
	1. This was developed in windows platform
	2. Script is static, most of the variables values are pre-assigned 
	3. This is no where near production-ready. Still a lot of improvements to be made.
	4. Supported Languages are C/C++/Objective-C/Fortran77/Ada - Languages supported by GCC (GNU Compiler Collection)
	
	Improvements
	
	1. Check the source code for any critical system functions and remove them
	2. Build a neat web interface around
**/
// Current working directory
$cwd = 'c:/Users/krishna/';
// Time limit for the current program to execute
$time_limit = 1; // This has to be an integer. 
// Environmental variable values to set for execution
$env = array();
// Start time of the script
$start_time = 0;
// End time of the script
$end_time = 1;

// Step 1 - Compile the program
// Compiler execution descriptor
$compiler_descriptorspec = array(
   0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
   1 => array("file", "./hello.compile.output", "w"),  // stdout is a file that the child will write to
   2 => array("file", "./error-output.txt", "w") // stderr is a file to write to
);

// Execute the compiler
// I assume that GCC is present in your executable path
$process = proc_open('gcc hello.c -o hello.exe -ftime-report -fmem-report', $compiler_descriptorspec, $pipes, $cwd);
// Validate the compiler output
if (is_resource($process)) {
    $return_value = proc_close($process);

	// echo "Compiler output is $return_value";
	if($return_value != 0) die("Compile Error");
	
}

// Step 2 - Execute the program, only if there is no compile error
$descriptorspec = array(
   0 => array("file", "./hello.input", "r"),  // stdin is a pipe that the child will read from
   1 => array("file", "./hello.output", "w"),  // stdout is a pipe that the child will write to
   2 => array("file", "./error-output.txt", "a") // stderr is a file to write to
);

// Original file which is used as output reference
$output_reference = './hello.output.test';

// Start the Counter
$start_time = time();

// Start the program execution
$process = proc_open('hello.exe', $descriptorspec, $pipes, $cwd, $env);

// Time to sleep, for the program to complete
sleep($time_limit);
// Now awake up to see if the execution is complete
$status = proc_get_status($process);
if($status['running']) {
	$end_time = time();
	// echo "Total Time taken - " . date('H:m:s');
	// If the process is still running, terminate it
	proc_terminate($process);
	die("ERROR: Time limit exceeded");
}

if(is_resource($process)) {
    // It is important that you close any pipes before calling
    // proc_close in order to avoid a deadlock
    $return_value = proc_close($process);
	$end_time = time();
	// echo "Total Time taken - " . date('H:m:s', $end_time - $start_time);
	
	if($return_value == 0) {
		// Time to compare the program output with output reference
		$test_output = trim(file_get_contents($output_reference));
		$command_output = trim(file_get_contents('./hello.output'));
		$cmp_value = strcmp($test_output, $command_output);
		
		if($cmp_value === 0) {
			die("SUCCESS: Accepted!");
		} else {
			die("ERROR: Output does not match!");
		}
	} else {
		die("ERROR: Program Exited with code oter than 0");
	}
} else {
	// proc_open did not work at all
	die("TECHICAL_ERROR: proc_open did nt work properly, Please chk that out for me. ");
}

hello.c

// Sample program for testing the online judge script
int main() {
	int a, b, c, n, i;

	scanf("%d", &n);
	
	// for(i = 0; i < n + 10000000000000; i++) { -- For time limit execeeded
	for(i = 0; i < n; i++) {
		scanf("%d%d", &a, &b);

		// c = a - b; Wrong output case
		c = a + b;	// Success in execution
		printf("%d\n", c);
	}
	
	// return 5; -- ERROR with invalid return code
	return 0;
}

hello.input

3
2
3
1
1
2
2

hello.output.test

5
2
4