tunefs, that sophisticated system administrators use to change the dynamic parameters of a
filesystem and improve the block layout on disk.
[1] Probably designed by some old farmer named McDonald.
The on-line manual pages of the original tunefs, like all Berkeley commands, ended with a "Bugs"
section. In this case, it read:
Bugs:
This program should work on mounted and active file systems,
but it doesn't. Because the superblock is not kept in the
buffer cache, the program will only take effect if it is run
on dismounted file systems; if run on the root file system,
the system must be rebooted. You can tune a file system, but
you can't tune a fish.
Even better, the word-processor source had a comment in it, threatening anyone who removed that last
phrase! It said:
Take this out and a UNIX Demon will dog your steps from now
until the time_t's wrap around.
When Sun, along with the rest of the world, changed to SVr4 UNIX, we lost this gem. The SVr
manpages don't have a "Bugs" section—they renamed it "Notes" (does that fool anyone?). The "tuna
fish" phrase disappeared, and the guilty party is probably being dogged by a UNIX demon to this day.
Preferably lpd.
Programming Challenge
Computer Dating
When will the time_t's wrap around?
Write a program to find out.