-O
Never add a null byte V8.2 and later
If neither -N
nor
-O
is
specified, sendmail uses an
adaptive algorithm to decide whether to look for the
terminating zero byte. The algorithm starts by
accepting either possibility. If the first key
looked up is found to end with a terminating zero
byte, the algorithm will thereafter look only for
keys with a terminating zero byte. If the first key
that is looked up is found to not end with a
terminating zero byte, the algorithm will thereafter
look only for keys without a terminating zero
byte.
If this -O
switch
is specified, sendmail never
tries a zero byte, which can speed matches. Note
that if both -N
and -O
are
specified, sendmail will not
produce an error message, and will never try to
match at all, thus causing all lookups to appear to
fail.
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