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Text File | 1993-07-29 | 6.2 KB | 169 lines | [TEXT/R*ch] |
-
- cron
- Version 1.0d13 of 29-Jul-93
-
- by Chris Johnson
-
-
-
- Changes in cron 1.0d13:
-
- • Cron now runs as a background-only application, so you won't
- see it in the application menu anymore. (If you liked it the
- way it was before, use ResEdit to alter the "Background Only"
- bit in cron's SIZE resource.)
-
- • Cron uses less memory, especially when used in its default
- background-only configuration.
-
- • Cron includes some on-board diagnostics which may help people
- track down problems in a few obscure situations. Basically,
- it's simple stuff; alerts will appear to let you know that
- some part of program initialization failed, or that it ran
- out memory while trying to do something, etc.
-
- • The "argc Receiver.c" file has been altered such that it
- works correctly for commands built to execute as background-
- only tasks.
-
- • The "argc Receiver.c" file has been altered such that it now
- accepts multiple sets of parameters at one time. In the past,
- commands accepted only the first set of parameters they were
- passed at any given time. This is more of a limitation in the
- Mac OS than in the cron code. Note that the option to receive
- multiple sets of parameters in a command must be enabled by
- defining the "ReinvokeMain" symbol in the command project,
- and your code must be prepared to cleanup behind itself
- completely, etc. If we could just fork processes, none of this
- would be necessary, of course.
-
- • The 1.0d10 version of the "argc Receiver.c" file has been
- ported to THINK Pascal by Peter N. Lewis, so Pascal pro-
- grammers should be able to join in the fun now. :-)
-
-
- Changes in cron 1.0d10:
-
- • Cron no longer crashes when the system clock is set back.
-
- • The open command now resolves aliases to the files it is
- instructed to open.
-
- • The old echo command was rewritten from scratch by Mike Pearce
- such that it now echos its arguments to Notification Manager
- alerts for which timeout values can be supplied. This creates
- a very useful way for cron to provide users a reminder service.
- Thank you, Mike.
-
- • The "tcp time client" command has been added. This command
- will query TCP-based Time Protocol (RFC 868) servers and set
- the Mac's clock accordingly. It will optionally allow for
- the U.S. Daylight Savings Time (DST) convention.
-
- • The "activity-report" command has been added. This command
- brings up a window on the user's screen into which they can
- type up to 255 characters of text. The text is recorded in
- a log file with a time stamp attached to each entry. This
- is useful for keeping track of one's daily activities in
- order to satisfy demanding management.
-
-
- Changes in cron 1.0d9:
-
- • Cron now resolves aliases to commands and to the crontab file.
- The aliases must have exactly the same names as the files they
- represent, i.e. an alias to the crontab file named "crontab
- alias" will not work.
-
- • Most of the text files supplied with, and created by, this
- version of cron are setup to work with Rich Siegel's marvelous
- BBEdit text editor, instead of TeachText as with previous
- versions.
-
- If you don't have a copy of BBEdit, I recommend getting one.
- Even so, if you'd rather not get BBEdit, they're still just
- plain old text files, so you can edit and view them with almost
- anything.
-
- • Cron supports several extensions to the standard crontab format.
- These include the options of scheduling events relative to the
- time at which the Mac: starts-up, goes idle, or becomes busy.
-
-
- Points of interest:
-
- • Source code for cron and most of its commands is available.
-
- • All source code was written for THINK C 5, but should be easy to
- get working in MPW C, since both environments are (essentially)
- ANSI compliant and use the same headers at long last.
-
- • Cron looks for its crontab file in the same directory as the cron
- application.
-
- • Currently, there is no Mac front-end to the crontab data file,
- i.e. there's no user interface for cron; you just edit the crontab
- file and cron reacts accordingly. I will, however, be happy to
- write one if there's sufficient interest in the cron product to
- make it worthwhile.
-
- • I hope cron and its associated commands can become a public
- development effort (assuming anyone finds it useful, of course).
- If you create new commands, please send them and their source
- (whenever possible) to me so they can be redistributed, along with
- all the other commands and sources, in subsequent test versions.
-
- • Input on all aspects of this project is welcome.
-
-
-
- Chris Johnson
-
- Internet: chrisj@emx.cc.utexas.edu
- UUCP: {husc6|uunet}!cs.utexas.edu!ut-emx!chrisj
- BITNET: chrisj@utxvm.bitnet
- CompuServe: >INTERNET:chrisj@emx.cc.utexas.edu
- AppleLink: chrisj@emx.cc.utexas.edu@internet#
- U.S. Mail: Chris Johnson, 4505-B Avenue H, Austin, TX 78751
-
-
-
-
-
- —————————————————————————————————————————————
- INFORMATION INCLUDED BELOW
- —————————————————————————————————————————————
- • Cron and Pathnames
- —————————————————————————————————————————————
-
-
-
- Cron and Pathnames
- —————————————————————————————————————————————
-
- In the absence of a pathname, cron will not find its commands unless
- they are located in the same directory as cron.
-
- If you supply partial pathnames as arguments, they are evaluated
- relative to the location of the program that ultimately processes the
- arguments. Full pathnames are supported, of course, so you can
- avoid the ambiguity of partial pathnames.
-
- Personally, I just create a cron directory and put a copy of the cron
- program and all its commands in it. This way I can avoid the whole
- pathname issue when invoking commands. Another way to avoid the whole
- issue is to create aliases to items in other directories, and place
- those aliases in the cron folder. Pathnames can be a pain, so I
- suggest using both of the above tactics as appropriate, and avoiding
- pathnames wherever possible.
-
- One tip: use the open command with the -c (launch by creator code)
- option when you want to run conventional applications located outside
- the cron directory, in situations where aliases aren't appropriate.
- This way the desktop database is used to locate the most recent
- version of the program on any of your mounted disks and you can avoid
- the fragility of path names entirely. Of course, this only works with
- programs that have their own icons and are located on mounted HFS
- disks.
-
-