Re: 'loop' vs 'loop=device' in _mount

[Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>]

On Wed, 26 Aug 2009 18:03:32 -0400 (EDT)
"Benjamin R. Haskell" <zsh@xxxxxxxxxx> wrote:
> When using completion for mount options, I often run into the annoyance 
> that the 'loop' option prompts for the loopback devide to use.  Really, 
> though, one needn't specify any device in particular...  Says the man-page 
> for 'mount':
> 
> '''
> If no explicit loop device is mentioned (but just an option `-o loop' is 
> given), then mount will try to find some unused loop device and use that.
> '''
> 
> I'll likely just patch my own completion script to change:
> 
> Completion/Unix/Command/_mount, line 325:
> -      'loop[use loopback device]:loopback device:_files'
> +      'loop[use loopback device]'
> 
> since I couldn't tell how to incorporate an '-o' option that accepts an 
> optional argument.

It should be just a question of doubling the first colon, as follows
(see the documentation for _values).  However, I couldn't get the suffix
(i.e. the "=") added to be removed when I typed ",", i.e. tried to add a
new list option instead of an argument... until it finally occurred to
me after an astonishing amount of looking in completely the wrong place
that I hadn't told it when to remove it (patch to _values---so non-final
optional arguments to values were always a bit inconvenient).

The following should do more or less what you want; the behaviour is
like that after "/" in file names, but the "," will cause the
auto-remove behaviour of the "=", too.

Index: Completion/Base/Utility/_values
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Base/Utility/_values,v
retrieving revision 1.11
diff -u -r1.11 _values
--- Completion/Base/Utility/_values	13 Jan 2009 12:19:53 -0000	1.11
+++ Completion/Base/Utility/_values	27 Aug 2009 20:34:30 -0000
@@ -59,7 +59,7 @@
       _describe "$descr" \
         noargs "$sep[@]" -M 'r:|[_-]=* r:|=*' -- \
         args -S "${argsep}" -M 'r:|[_-]=* r:|=*' -- \
-        opts -qS "${argsep}" -M 'r:|[_-]=* r:|=*'
+        opts -qS "${argsep}" -r "${argsep}${sep} \\t\\n\\-" -M 'r:|[_-]=* r:|=*'
 
       curcontext="$oldcontext"
 
Index: Completion/Unix/Command/_mount
===================================================================
RCS file: /cvsroot/zsh/zsh/Completion/Unix/Command/_mount,v
retrieving revision 1.29
diff -u -r1.29 _mount
--- Completion/Unix/Command/_mount	4 Jun 2009 15:32:22 -0000	1.29
+++ Completion/Unix/Command/_mount	27 Aug 2009 20:34:31 -0000
@@ -322,7 +322,7 @@
       '(nosuid)suid[use suid and sgid bits]'
       '(async)sync[do I/O synchronously]'
       'dirsync[perform directory updates synchronously]'
-      'loop[use loopback device]:loopback device:_files'
+      'loop[use loopback device]::loopback device:_files'
       'encryption[enable encryption]:cypher'
       'keybits[set number of bits in encryption key]:key size:(64 128 160 192 256)'
       'offset[specify data start for loopback mount]:offset (bytes)'

-- 
Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/