通过php脚本将文件添加到crontab

Question

I've found at this forum that it is possible to edit crontab like this:
a. crontab -l > $tmpfile
b. edit $tmpfile
c. crontab $tmpfile
d. rm $tmpfile
So, I'm trying to implement this solution on php:

include('Net/SSH2.php');
$ssh = new Net_SSH2('myhost');
if (!$ssh->login('user', 'password')) 
{
    echo'Login Failed';
}

    $ssh->exec('crontab -l > /var/www/tmp.txt');
    $content=file_get_contents("/var/www/tmp.txt");
    $content.='0 0 1 * * /usr/bin/php /var/www/clearPreviousMonth1.php';
    $file=fopen("/var/www/tmp.txt", "w");
    fputs($file,$content);
    fclose($file);
    $ssh->exec('crontab /var/www/tmp.txt');
    echo $content;

I can see edited content of crontab in my browser and tmp file, but when I use crontab -e it's not changed. What's my mistake?

Answer 1

I had to add new string before the end of file. In other case it's not added to crontab. changed $content.='0 0 1 * * /usr/bin/php /var/www/clearPreviousMonth1.php'; to $content.="0 0 1 * * /usr/bin/php /var/www/clearPreviousMonth1.php\\n"; note that it's neccessary to use " instead of ' , because it just will append \\n symbols to last string