Alan Stebbens wrote,
| If you wish to "modify the body of the message", and pass it back, then
| use the "fb" flags (please read procmailrc(1)):
Yes, except that the procmailrc man page is in chapter 5 of the manual,
not chapter 1, so it's procmailrc(5).
| If the filterprogram exits with a 0 status (0 == okay), then procmail
| will replace the original input body with the output of the
| filterprogram. If the filterprogram exits with anything but zero,
| procmail will report an "error" to the log, and "recover" the input (not
| filter it).
I am very sure that that's the case ONLY if you have the `w' or `W' flag on
the filtering recipe. Without `w' or `W', procmail won't care about a bad
exit status from the filter and will replace the filtered portion with what-
ever standard output the filter produced. It may still report an error to
the log but it won't recover the previous text. This, for example, will
destroy the body of a message, even without `i':
:0fb
| false
With this, however, procmail will recover the original body:
:0fbW # same results even if we add `i'
| false