How can I tell if a file is older than 30 minutes from /bin/sh?

Question

How do I write a script to determine if a file is older than 30 minutes in /bin/sh? Unfortunately does not the `stat` command exist in the system. It is an old Unix system, http://en.wikipedia.org/wiki/Interactive_Unix Perl is unfortunately not installed on the system and the customer does not want to install it, and nothing else either.

Accepted Answer

Here's one way using `find`.

```
if test "`find file -mmin +30`"
```

The `find` command must be quoted in case the file in question contains spaces or special characters.

How can I tell if a file is older than 30 minutes from /bin/sh?

Solution

Problem