Cron for Macintosh by Chris W. Johnson

Several updated Cron commands are available. These include a new MountAFP that should solve problems several people have reported with the old MountAFP command when used with modern versions of Mac OS. 8-June-1999.

Alpha Test?

Yes, alpha test. After five years of keeping Cron in developmental testing, it's finally time to move it along to alpha testing. The alpha test versions will address issues related to the latest system software (memory/stack shortages), frequently reported problems and misunderstandings (the "open" command is history), and offer a growing number of user interface improvements. Yes, a user interface. It won't be much in the early alphas but it should be quite decent in the late alphas. Finally, unfortunately, Cron will become shareware ($10). It just isn't feasible to continue this project as freeware.

The first public alpha version, 1.0a7, is available via HTTP here or, via FTP from the pub/chrisj directory of ftp.utexas.edu.

Cron is a background-only application which, quietly and efficiently, launches other applications, or opens documents, at specified dates and times. You can use it, for example, to reboot your Mac in the middle of the night and rebuild its desktop file, run your favorite email program just before you arrive in your office each morning, notify you of important dates and times (like quitting time, or your dog's birthday), etc.

Cron will launch any application at any time you like, and it can even pass parameters to specially designed programs, known as cron commands (for lack of any better name), in order to regulate their behavior. Programmers will find cron commands easy to write because all the necessary source code (in C and Pascal) for interfacing with Cron is available. C programmers will find them especially easy to write, as the parameters passed to commands are received in the standard argc/argv format. By writing Cron commands almost any functionality desired can be placed under Cron's control.

Cron is based directly on the cron daemon in BSD 4.3 UNIX. There's no common source code at any level, but the format of the Cron commands file (crontab) is identical.

The lastest version of Cron is available via HTTP here, or via FTP from the pub/chrisj directory of ftp.utexas.edu.

Additional Resources:

• Cron FAQ (Frequently Asked Questions list).
• Jerry Stratton's "Programming Cron Scripts" page.

Features:

• Highly flexible event scheduling inherited from its UNIX namesake.
• Macintosh-specific event scheduling options.
• Launches/opens applications, AppleScript applets, desk accessories, documents, and a variety of included cron commands.
• Excellent compatibility. Cron is a conventional Macintosh application, not an Extension, Control Panel, etc., and it does not patch any traps.
• Variety of bundled Cron commands that perform tasks such as synchronizing your Mac's clock with Internet Time Protocol servers, mounting/unmounting AppleShare servers, issuing commands to remote hosts via rexec, restarting the Mac and rebuilding its desktop, quitting applications, displaying messages for the user, opening URLs, etc.
• Simple Internet Version Control protocol (SIVC) support.
• Convenient shareware fee payment (on-line, even) via Kagi shareware registration service.
• Fat binary - runs at full speed on Macintoshes and Power Macintoshes alike.

Requirements:

• System 7.0 or better.
• Apple's Thread Manager extension (built into System 7.5 and all later systems). Actually, only the Cron Setup utility requires the Thread Manager, but that's reason enough to install it.
• Text Editor - SimpleText works up to a point, but BBEdit is recommended.

Recommended Items & Capabilities:

• Internet connection via MacTCP or Open Transport.
• Internet Config - makes all Internet-oriented features much happier.
• Espy Sans, Helvetica and Palatino fonts.

Most Obvious Shortcoming:

• No WYSIWYG editor for the crontab file.

Third-Party Products

Any C or Pascal programmer can write commands for cron, and some of them actually do. Only a few ever release their products to the world, however. Here's one of those products. If you know of others, let me know.

CronX10

CronX10, by Jerry Gatlin, is a cron command which allows your Macintosh to control the lights, appliances and thermostats in your house through the standard X10 controller modules available from Leviton, Radio Shack, etc. Now cron can control more than just your Macintosh.

Download version 1.0b6 of the cronX10 module.