Today I noticed a problem with the FreshPorts email processing daemon. It’s not really a daemon. It’s a shell script. After a reboot, I noticed the script was not running. Trying the script by hand, I found this error message:
.: missing filename
This sample script duplicates the problem:
#!/bin/sh while . do sleep 1 echo slept done
On 4.11 and 6.1, it runs fine. On FreeBSD 6.2-PRERELEASE #0: Thu Nov 9 15:30:25 EST 2006, you get the error mentioned above. I fixed the problem by using
while true. I’m told that
while : will work just as well, and should be more portable. : is a built in shell command. From man sh:
: A null command that returns a 0 (true) exit value.
I think I’ll use
while : from now on.