era eriksson wrote:
:0 fwh: perl.lock tells procmail that this recipe is a filter (f),
to send only the header to the filter (h), and to check the exit
code for success or failure (w).
Actually the w also means Procmail will hang around and wait for the
filter to finish running.
No, that's implied by plain "f" already - after all, procmail
needs the filtered message for the next recipe. The "w" only
changes what happens after a failure of the filter. To quote
http://www.procmail.org/jari/pm-tips-body.html#flag_f_and_w_together :
| [david] Of course the f flag is enough to make procmail wait
| for the filter to finish, but the w means something more: to
| wait to learn the exit code of the filtering command. If sed
| fails with a syntax error and gives no output, without W or w
| procmail would happily accept the null output as the results
| of the filter and go on reading recipes for the now body-less
| message. On the other hand, with W or w sed will respond to a
| non-zero exit code by recovering the unfiltered text.
/HW