Under the `-n` option, the man page currently says To show settings that differ from built-in defaults only, use the following bash syntax: comm -23 <(postconf -n) <(postconf -d) Replace "-23" with "-12" to show settings that duplicate built-in defaults.
Curiously, with the typical LANG=en_US.UTF-8, this complains that the inputs are not sorted. It fails at the transition from smtp to smtpd lines: smtp_[whatever] smtpd_[whatever] because, apparently, the highly complex Unicode collation rules modify how the underscore character (0x5f) is treated. I couldn't find a reference explaining exactly why, but it seems to be related to "variable collation elements". Adding LC_ALL=C to the front of the comm command cures the problem. So I'd like to suggest that the manpage either add the LC_ALL=C prefix or include a warning about the possible issue under Unicode locales. -- Jim Garrison j...@acm.org