Prior to V8
sendmail, if the list of recipients contained an
address that began with any of the prescanned switches,
sendmail would wrongly view that recipient as a
switch during its prescan phase. For example, mail to joe,
bill, -Cool caused sendmail to try to
use a file named ool as its configuration file.
Command-line switches must precede recipient addresses. Switches that
are mixed in with recipient names are treated as recipient addresses.
Old versions of sendmail (including IDA and some
versions of BSD) would syslog(3) a warning if
the old frozen configuration file didn't exist. The
V8 and SunOS versions of sendmail no longer
check for a frozen configuration file, so nothing is ever logged
about this.
Prior to V8 sendmail, unknown command-line
switches were silently ignored. Therefore, sending mail from a shell
script could fail for reasons that were difficult to find. For
example, specifying the preliminary hop count wrongly with
-j, instead of correctly with
-h, caused your presetting of the hop count to be
silently ignored.
Some old BSD and SunOS versions of sendmail set the default
sender's full name from the environment variable
NAME even when running as a daemon or when processing the queue. This
can lead to the superuser's full name occasionally
showing up wrongly as a sender's full name. IDA and
V8 sendmail clear the full name in
-bd and -q modes but use
different methods. To prevent this problem under other versions of
sendmail, the env(1)
program can be used to clean up the environment passed to
sendmail:
# env - /usr/sbin/sendmail -bd -q1h
V8 sendmail uses getopt(3)
to parse its command-line arguments so that a switch and its argument
can have whitespace between them without harm:
-C configfile
But, for bizarre historical reasons, the -d and
-q switches differ from all other command-line
switches. There can never be space between the -d
and its arguments, nor between the -q and its
arguments:
-d 4
-q 4
If there is space between them, the argument (here,
4) is taken to be a recipient name. This is true
for all versions of sendmail.
