Re: [Nmh-workers] semantics of mhshow -type and -part

[Paul Fox]

ralph wrote:
 > Hi Paul,
 > 
 > > > So if I do `-type text/plain -part 4' to read the email and get that
 > > > particular interesting PDF, I get nothing?
 > > 
 > > yes, that's right.  but i think that's already true in current git
 > 
 > Yes, you're right!  I checked git's mhlist(1) and it doesn't seem to
 > state it's (part42 || part314) && (text/plain || image/png) if both
 > -part and -type are given?  Should I be looking somewhere else?

for documentation?  no, the current behavior was relatively
undocumented.  i've improved it some, but perhaps not enough.  oh -- i
knew i hadn't uniformly updated the several affected man pages, but
didn't realized i'd only put this in mhshow(1):
   The -type switch can also be used to restrict (or, when  used  in  con‐
   junction  with -part, to further restrict) the display of parts accord‐
   ing to content type.  One or more -type switches part will only  select
   the  first  match  from  a multipart/alternative, even if there is more
   than one subpart that matches (one of) the given content type(s).

"further restrict" might be too subtle.  i had trouble with the
wording because of the "if -part and -type are both given" clause you
wrote above.  but maybe you're on the right track.  if only one of -part
or -type is used, then you get the union of the parts selected.  if
both are used, you get the intersection of those unions.

(this is a case where having a "common options" man page would be very
handy.  the individual commands could have a brief synopsis of the
behavior, with a pointer to a subsection to mh-switches(1) for the
full details.  i balked at putting all the gore on all the man pages,
and i guess i shouldn't have.)

paul
=----------------------
 paul fox, address@hidden (arlington, ma, where it's 28.2 degrees)