<?php
class p_grep extends prog {
	public static function flag($flags,$flag) {
		return (strpos($flags,$flag)!==false);
	}
	public static function recurse_grep($pattern, $subject, $flags = '') {
		// Do a breadth-first search
		$dirs = array();
		if ( is_dir($subject) ) {
			$dirs[] = $subject;
		} else {
			self::grep($pattern, $subject, $flags);
		}
		foreach($dirs as $dir) {
			$dh = opendir($dir);
			while(false !== ( $file = readdir($dh)) ) {
				if (( $file != '.' ) && ( $file != '..' )) {
					self::recurse_grep($pattern, $subject.'/'.$file, $flags);
				}
			}
			closedir($dh);
		}
	}

	public static function grep($pattern, $file, $flags) {
		$lines = preg_split("/\r\n/",file_get_contents($file));
		foreach ($lines as $line_number => $line_contents) {
			if (preg_match($pattern,$line_contents)>0) {
				if (
					   (self::flag($flags,'r') && !self::flag($flags,'h')) // recursive
					|| (self::flag($flags,'H')) // or explicit
				) { echo htmlentities($file).': '; }
				if (self::flag($flags,'n')) { echo $line_number.': '; }
				echo htmlentities($line_contents)."\n";
			}
		}
	}

	public static function main($args, $env) {
		$me = array_shift($args);
		$flags = '';
		while (substr($args[0],0,1) == '-') {
			$flags .= array_shift($args);
		}
		$flags = preg_replace('/[ -]/','',$flags);
		$pattern = array_shift($args);
		foreach ($args as $file) {
			if (self::flag($flags,'r')) { self::recurse_grep($pattern, $file, $flags); }
			else {                           self::grep($pattern, $file, $flags); }
		}
	}
}