Cron runs but PHP doesn't

Server: Ubuntu 12.04 Web Server: nginx PHP5-cli is installed.

I’ve edited /etc/crontab and added a new entry that executes a PHP script.

The cron job seems to be running fine but the PHP file isn’t doing anything.

I’ve check the permissions on the PHP file and they are set to 755.

The PHP file basically writes data to a TXT file and send an email. if I execute the PHP directly in the terminal, everything works as expected.

However, via the crontab, it doesn’t.

Here is the contents of my crontab:

SHELL=/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

17 * * * * root cd / && run-parts --report /etc/cron.hourly 25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily ) 47 6 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly ) 52 6 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly ) */5 * * * * root /usr/bin/php /usr/share/nginx/html/functions/cron-test.php > /dev/null 2>&1

I’ve set the cron to run every 5 mins so I can check it is working…

If I run “grep CRON /var/log/syslog” in the terminal, I can see entries related to the cron entry.

Any ideas?