<?php
define('CRON_COMMENT', 0);
define('CRON_ASSIGN', 1);
define('CRON_CMD', 2);
define('CRON_SPECIAL', 3);
define('CRON_EMPTY', 4);
/**
* A class that interfaces with the crontab. (cjpa@audiophile.com)
*
* This class lets you manipulate a user's crontab.
* It lets you add delete update entries easily.
*
* @package Airtime
* @subpackage StorageServer.Cron
*/
class Crontab
{
// {{{ properties
/**
* Holds all the different lines.
* Lines are associative arrays with the following fields:
* "minute" : holds the minutes (0-59)
* "hour" : holds the hour (0-23)
* "dayofmonth" : holds the day of the month (1-31)
* "month" : the month (1-12 or the names)
* "dayofweek" : 0-7 (or the names)
*
* or a line can be a 2-value array that represents an assignment:
* "name" => "value"
* or a line can be a comment (string beginning with #)
* or it can be a special command (beginning with an @)
* @var array
*/
private $crontabs;
/**
* The user for whom the crontab will be manipulated
* @var string
*/
private $user;
/**
* Lists the type of line of each line in $crontabs.
* can be: any of the CRON_* constants.
* so $linetype[5] is the type of $crontabs[5].
* @var string
*/
private $linetypes;
// }}}
/**
* Constructor
*
* Initialises $this->crontabs
*
* @param string $user the user for whom the crontab will be manipulated
*/
function Crontab($user)
{
$this->user = $user;
$this->readCrontab();
}
/**
* This reads the crontab of $this->user and parses it in $this->crontabs
*
*/
function readCrontab()
{
// return code is 0 or 1 if crontab was empty, elsewhere stop here
$cmd = "crontab -u {$this->user} -l";
@exec("crontab -u {$this->user} -l", $crons, $return);
if ($return > 1) {
return PEAR::raiseError("*** Can't read crontab ***\n".
" Set crontab manually!\n");
}
foreach ($crons as $line)
{
$line = trim($line); // discarding all prepending spaces and tabs
// empty lines..
if (!$line) {
$this->crontabs[] = "empty line";
$this->linetypes[] = CRON_EMPTY;
continue;
}
// checking if this is a comment
if ($line[0] == "#") {
$this->crontabs[] = trim($line);
$this->linetypes[] = CRON_COMMENT;
continue;
}
// Checking if this is an assignment
if (ereg("(.*)=(.*)", $line, $assign)) {
$this->crontabs[] = array ("name" => $assign[1], "value" => $assign[2]);
$this->linetypes[] = CRON_ASSIGN;
continue;
}
// Checking if this is a special @-entry. check man 5 crontab for more info
if ($line[0] == '@') {
$this->crontabs[] = split("[ \t]", $line, 2);
$this->linetypes[] = CRON_SPECIAL;
continue;
}
// It's a regular crontab-entry
$ct = split("[ \t]", $line, 6);
$this->addCron($ct[0], $ct[1], $ct[2], $ct[3], $ct[4], $ct[5]);
}
}
/**
* Writes the current crontab
*/
function writeCrontab()
{
global $DEBUG, $PATH;
if (empty($this->linetypes)) {
return;
}
$filename = ($DEBUG ? tempnam("$PATH/crons", "cron") : tempnam("/tmp", "cron"));
$file = fopen($filename, "w");
foreach($this->linetypes as $i => $line) {
switch ($this->linetypes[$i]) {
case CRON_COMMENT:
$line = $this->crontabs[$i];
break;
case CRON_ASSIGN:
$line = $this->crontabs[$i][name]." = ".$this->crontabs[$i][value];
break;
case CRON_CMD:
$line = implode(" ", $this->crontabs[$i]);
break;
case CRON_SPECIAL:
$line = implode(" ", $this->crontabs[$i]);
break;
case CRON_EMPTY:
$line = "\n"; // an empty line in the crontab-file
break;
default:
unset($line);
echo "Something very weird is going on. This line ($i) has an unknown type.\n";
break;
}
// echo "line $i : $line\n";
if ($line) {
$r = @fwrite($file, $line."\n");
if($r === FALSE) {
return PEAR::raiseError("*** Can't write crontab ***\n".
" Set crontab manually!\n");
}
}
}
fclose($file);
if ($DEBUG) {
echo "DEBUGMODE: not updating crontab. writing to $filename instead.\n";
} else {
exec("crontab -u {$this->user} $filename", $returnar, $return);
if ($return != 0) {
echo "Error running crontab ($return). $filename not deleted\n";
} else {
unlink($filename);
}
}
}
/**
* Add a item of type CRON_CMD to the end of $this->crontabs
*
* @param string $m
* minute
* @param string $h
* hour
* @param string $dom
* day of month
* @param string $mo
* month
* @param string $dow
* day of week
* @param string $cmd
* command
*
*/
function addCron($m, $h, $dom, $mo, $dow, $cmd)
{
$this->crontabs[] = array ("minute" => $m, "hour" => $h, "dayofmonth" => $dom, "month" => $mo, "dayofweek" => $dow, "command" => $cmd);
$this->linetypes[] = CRON_CMD;
}
/**
* Add a comment to the cron to the end of $this->crontabs
*
* @param string $comment
*/
function addComment($comment)
{
$this->crontabs[] = "# $comment\n";
$this->linetypes[] = CRON_COMMENT;
}
/**
* Add a special command (check man 5 crontab for more information)
*
* @param string $sdate special date
* string meaning
* ------ -------
* @reboot Run once, at startup.
* @yearly Run once a year, "0 0 1 1 *".
* @annually (same as @yearly)
* @monthly Run once a month, "0 0 1 * *".
* @weekly Run once a week, "0 0 * * 0".
* @daily Run once a day, "0 0 * * *".
* @midnight (same as @daily)
* @hourly Run once an hour, "0 * * * *".
* @param string $cmd command
*/
function addSpecial($sdate, $cmd)
{
$this->crontabs[] = array ("special" => $sdate, "command" => $cmd);
$this->linetypes[] = CRON_SPECIAL;
}
/**
* Add an assignment (name = value)
*
* @param string $name
* @param string $value
*/
function addAssign($name, $value)
{
$this->crontabs[] = array ("name" => $name, "value" => $value);
$this->linetypes[] = CRON_ASSIGN;
}
/**
* Delete a line from the arrays.
*
* @param int $index the index in $this->crontabs
*/
function delEntry($index)
{
unset ($this->crontabs[$index]);
unset ($this->linetypes[$index]);
}
/**
* Get all the lines of a certain type in an array
*
* @param string $type
*/
function getByType($type)
{
if ($type < CRON_COMMENT || $type > CRON_EMPTY)
{
trigger_error("Wrong type: $type", E_USER_WARNING);
return 0;
}
$returnar = array ();
for ($i = 0; $i < count($this->linetypes); $i ++)
if ($this->linetypes[$i] == $type)
$returnar[] = $this->crontabs[$i];
return $returnar;
}
}