Re: [ramk@cse.iitm.ernet.in: Bug#335190: zsh: Enhancements to zsh-mime-handler]

[Peter Stephenson <p.w.stephenson@ntlworld.com>]

On Mon, 24 Oct 2005 15:33:18 -0400
Clint Adams <schizo@debian.org> wrote:
> ----- Forwarded message from "R.Ramkumar" <ramk@cse.iitm.ernet.in> -----
> 
> Just felt that there is much scope for customization in
> zsh-mime-{handler,setup}. I have patched the files for the following
> enhancements (thought that the additions were too small to merit
> reporting them individually, so I am putting them together):

Thanks, I'll add these.  Here's some proposed documentation (styles now
put in alphabetical order).

It would be quite nice to have a couple of examples illustrating
mailcap-prio-flags.

Index: Doc/Zsh/contrib.yo
===================================================================
RCS file: /cvsroot/zsh/zsh/Doc/Zsh/contrib.yo,v
retrieving revision 1.51
diff -u -r1.51 contrib.yo
--- Doc/Zsh/contrib.yo	21 Oct 2005 09:51:55 -0000	1.51
+++ Doc/Zsh/contrib.yo	25 Oct 2005 22:43:22 -0000
@@ -1370,19 +1370,17 @@
 to style patterns in case the system is extended in future.  Some
 examples are given below.
 startitem()
-item(mime-types)(
-A list of files in the format of tt(~/.mime.types) and
-tt(/etc/mime.types) to be read during setup, replacing the default list
-which consists of those two files.  The context is tt(:mime:).
-A tt(PLUS()) in the list will be replaced by the default files.
+item(tt(current-shell))(
+If this boolean style is true, the mailcap handler for the context in
+question is run using the tt(eval) builtin instead of by starting a new
+tt(sh) process.  This is more efficient, but may not work in the occasional
+cases where the mailcap handler uses strict POSIX syntax.
 )
-item(mailcap)(
-A list of files in the format of tt(~/.mailcap) and
-tt(/etc/mailcap) to be read during setup, replacing the default list
-which consists of those two files.  The context is tt(:mime:).
-A tt(PLUS()) in the list will be replaced by the default files.
+item(tt(flags))(
+Defines flags to go with a handler; the context is as for the
+tt(handler) style, and the format is as for the flags in tt(mailcap).
 )
-item(handler)(
+item(tt(handler))(
 Specifies a handler for a suffix; the suffix is given by the context as
 tt(:mime:.)var(suffix)tt(:), and the format of the handler is exactly
 that in tt(mailcap).  Note in particular the `tt(.)' and trailing colon
@@ -1392,11 +1390,63 @@
 or if the output is to be displayed through a pager (but not if the
 handler is itself a pager), it should include tt(copiousoutput).
 )
-item(flags)(
-Defines flags to go with a handler; the context is as for the
-tt(handler) style, and the format is as for the flags in tt(mailcap).
+item(tt(mailcap))(
+A list of files in the format of tt(~/.mailcap) and
+tt(/etc/mailcap) to be read during setup, replacing the default list
+which consists of those two files.  The context is tt(:mime:).
+A tt(PLUS()) in the list will be replaced by the default files.
+)
+item(tt(mailcap-priorities))(
+This style is used to resolve multiple mailcap entries for the same MIME
+type.  It consists of an array of the following elements, in descending
+order of priority; later entries will be used if earlier entries are
+unable to resolve the entries being compared.  If none of the tests
+resolve the entries, the first entry encountered is retained.
+
+startitem()
+item(tt(files))(
+The order of files (entries in the tt(mailcap) style) read.  Earlier
+files are preferred.  (Note this does not resolve entries in the same file.)
+)
+item(tt(priority))(
+The priority flag from the mailcap entry.  The priority is an integer
+from 0 to 9 with the default value being 5.
+)
+item(tt(flags))(
+The test given by the tt(mailcap-prio-flags) option is used to resolve
+entries.
+)
+item(tt(place))(
+Later entries are preferred; as the entries are strictly ordered, this
+test always succeeds.
+)
+enditem()
+
+Note that as this style is handled during initialisation, the context
+is always tt(:mime:), with no discrimination by suffix.
+)
+item(tt(mailcap-prio-flags))(
+This style is used when the keyword tt(flags) is encountered in the
+list of tests specified by the tt(mailcap-priorities) style.
+It should be set to a list of patterns, each of which is tested against
+the flags specified in the mailcap entry (in other words, the sets of
+assignments found with some entries in the mailcap file).  Earlier
+patterns in the list are preferred to later ones, and matched patterns
+are preferred to unmatched ones.
 )
-item(pager)(
+item(tt(mime-types))(
+A list of files in the format of tt(~/.mime.types) and
+tt(/etc/mime.types) to be read during setup, replacing the default list
+which consists of those two files.  The context is tt(:mime:).
+A tt(PLUS()) in the list will be replaced by the default files.
+)
+item(tt(never-background))(
+If this boolean style is set, the handler for the given context is
+always run in the foreground, even if the flags provided in the mailcap
+entry suggest it need not be (for example, it doesnʼt require a
+terminal).
+)
+item(tt(pager))(
 If set, will be used instead of tt($PAGER) or tt(more) to handle
 suffixes where the tt(copiousoutput) flag is set.  The context is
 as for tt(handler), i.e. tt(:mime:.)var(suffix)tt(:) for handling