3.1.9 completion problems: automounter

3.1.9 completion problems: automounter

[E. Jay Berkenbilt]

I have /home set up to use an automounter.  Therefore, directories
under /home doesn't exist until I specifically access them.  As an
example, we have a directory called /home/sysadmin.  If I type

ls /home/sysadmin/

and hit TAB, I get no completions because zsh doesn't appear to
attempt to access /home/sysadmin at this point.  It only accesses
/home to see whether sysadmin exists, which it doesn't.  I have to do
something explicit to access /home/sysadmin first before I can use
completion.

Under tcsh, ls /home/sysadmin/ TAB works because tcsh actually
accesses /home/sysadmin before deciding whether it exists or not.

I'd like to know whether there is a way to get zsh to try to access
/home/sysadmin before deciding that there are no completions that
start from it.  Note: I am NOT looking for a way to type /home/sys TAB
and get sysadmin.  I am only looking for a way to get zsh to try
accessing the directory before deciding that it doesn't exist.

--
E. Jay Berkenbilt (ejb@ql.org)  |  http://www.ql.org/q/

more wishes with automounter

[Alexandre Duret-Lutz]

Hi,

I use automounter, too, and have trouble with Zsh.

I have a bunch of automounted NFS directories in
/var/autofs/nfs/

Since the automountable directories are invisible [*] in
/var/autofs/nfs/ until they are mounted, and because
I don't wan't to remember their names, I have setup
a /nfs/ directory with symbolic links to the automounted
directories:

   /nfs/hosts1 -> /var/autofs/nfs/host1
   /nfs/hosts2 -> /var/autofs/nfs/host2
   /nfs/hosts3 -> /var/autofs/nfs/host3
etc...

The problem is that using Zsh to complete /nfs/hos<TAB> will
mount *all* the directories, because the completion code stat()
all links (and stat()ing a link will lead to the mount of the
linked directory).  I believe that Zsh may use lstat() instead,
but since I don't know where that guilty stat() is I haven't
tried.

[*] another wish would be that Zsh complete those invisible
    directories; or more generaly: give the user the possiblity
    to add "virtual files" (anywhere he want), that Zsh would
    use for completion.
-- 
Alexandre Duret-Lutz

Re: 3.1.9 completion problems: automounter

[Bart Schaefer]

On Sep 11, 10:36am, E. Jay Berkenbilt wrote:
} Subject: 3.1.9 completion problems: automounter
}
} I'd like to know whether there is a way to get zsh to try to access
} /home/sysadmin before deciding that there are no completions that
} start from it.

Hmm.  I've just been playing with zsh on a machine at work that has an
automounted directory, and I can't reproduce the behavior you described.
If I type

zsh% ls /host/hostname<TAB>

I get a feep.  But if instead I type

zsh% ls /host/hostname/<TAB>

with the trailing slash, the mount happens and I get completions.  This
happens both with and without the new completion system loaded.  With
old-style completion, I get the following strace output, starting from
the point at which the TAB I typed is read:

read(10, "\t", 1)                       = 1
fcntl(0, F_DUPFD, 10)                   = 11
close(0)                                = 0
access("/bin/ls", X_OK)                 = 0
stat("/bin/ls", {st_mode=S_IFREG|0755, st_size=43024, ...}) = 0
open("/misc/moonbase/", O_RDONLY|O_NONBLOCK|O_DIRECTORY) = 0
fstat(0, {st_mode=S_IFDIR|0755, st_size=1024, ...}) = 0

So zsh *does* try to access the directory before deciding that it does
not exist.  Does open("/home/sysadmin/", ...) fail on your system?

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: 3.1.9 completion problems: automounter

[Bart Schaefer]

On Sep 12,  5:20am, Bart Schaefer wrote:
}
} Hmm.  I've just been playing with zsh on a machine at work that has an
} automounted directory, and I can't reproduce the behavior you described.
[...]
} with the trailing slash, the mount happens and I get completions.  This
} happens both with and without the new completion system loaded.

I'm sorry, I was mistaken about having loaded new completion.  With the
new completion system *properly* loaded, I *can* get this to happen.

So here's the answer to your question:

    zstyle -e ':completion:*' file-patterns '[[ -d $PREFIX:h/. ]]'

This tests whether the prefix (or "/", if there's no prefix, but that's
harmless) contains a "." directory, then ignores the result; so the only
effect is to force the directory to be automounted.  Since it does not
set a value for $reply (see the "zstyle -e" doc), completion proceeds as
if the style were not set at all.

Note that if you actually *want* to set file-patterns for some other
context, you'll have to add the test to those styles as well, or the
side-effect will go away in those contexts.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: more wishes with automounter

[Bart Schaefer]

On Sep 11,  7:33pm, Alexandre Duret-Lutz wrote:
} Subject: more wishes with automounter
}
}    /nfs/hosts1 -> /var/autofs/nfs/host1
}    /nfs/hosts2 -> /var/autofs/nfs/host2
}    /nfs/hosts3 -> /var/autofs/nfs/host3
} etc...
} 
} The problem is that using Zsh to complete /nfs/hos<TAB> will
} mount *all* the directories, because the completion code stat()
} all links (and stat()ing a link will lead to the mount of the
} linked directory).  I believe that Zsh may use lstat() instead,
} but since I don't know where that guilty stat() is I haven't
} tried.

I think the stat must be an effect of the way _path_files does globbing
to try to segregate files by type.  I don't see any stat() calls in
strace output if I don't have any styles set (and this time I did check
that the new completion system really was loaded (blush)).

Try this:

    ztyle -e ':completion:*' file-patterns \
      '[[ $PREFIX == /nfs/[^/]# ]] && \
        { setopt noglob ; reply=(*(@)) ; setopt glob }'

(Twaddling noglob like that was the only way I could get zstyle -e to put
a file pattern into $reply -- the eval-ing messed up any other quoting I
could think of.)  This just says that if you're completing within the
/nfs/ directory itself, don't consider anything other than symlinks.  As
I'm not sure why/where those links are getting stat()d, this may not be
of any help ... but then again, it may.

} [*] another wish would be that Zsh complete those invisible
}     directories; or more generaly: give the user the possiblity
}     to add "virtual files" (anywhere he want), that Zsh would
}     use for completion.

The article that PWS referenced about this is zsh-users/3408.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: more wishes with automounter

[Alexandre Duret-Lutz]

>>> "Bart" == Bart Schaefer <schaefer@candle.brasslantern.com> writes:

[...]

 Bart> Try this:

 Bart>     ztyle -e ':completion:*' file-patterns \
 Bart>       '[[ $PREFIX == /nfs/[^/]# ]] && \
 Bart>         { setopt noglob ; reply=(*(@)) ; setopt glob }'

 Bart> (Twaddling noglob like that was the only way I could get
 Bart> zstyle -e to put a file pattern into $reply -- the
 Bart> eval-ing messed up any other quoting I could think of.)
 Bart> This just says that if you're completing within the /nfs/
 Bart> directory itself, don't consider anything other than
 Bart> symlinks.  As I'm not sure why/where those links are
 Bart> getting stat()d, this may not be of any help ... but then
 Bart> again, it may.

This worked (i.e. directories are not automounted as a side effect
of completion).  But I couldn't get it to complete symlinks and
directories (my /nfs/ directory contains both).  Using:

    zstyle -e ':completion:*' file-patterns \
      '[[ $PREFIX == /nfs/[^/]# ]] && \
        { setopt noglob ; reply=(*(@,/)) ; setopt glob }'

Leads to:

~ % ls /nfs/<TAB>
_path_files:327: bad pattern: /nfs/*(@

 Bart> } [*] another wish would be that Zsh complete those invisible
 Bart> }     directories; or more generaly: give the user the possiblity
 Bart> }     to add "virtual files" (anywhere he want), that Zsh would
 Bart> }     use for completion.

 Bart> The article that PWS referenced about this is zsh-users/3408.

Thanks, I had to get it from the archives
(Murphy's law: my zsh-users mbox bumps from 3406 to 3408...)
-- 
Alexandre Duret-Lutz

Re: more wishes with automounter

[Bart Schaefer]

On Sep 13, 11:32am, Alexandre Duret-Lutz wrote:
} Subject: Re: more wishes with automounter
}
}     zstyle -e ':completion:*' file-patterns \
}       '[[ $PREFIX == /nfs/[^/]# ]] && \
}         { setopt noglob ; reply=(*(@,/)) ; setopt glob }'
} 
} Leads to:
} 
} ~ % ls /nfs/<TAB>
} _path_files:327: bad pattern: /nfs/*(@

This is because _files splits the file-patterns at commas on line 58.  I'm
not sure why, or how to fix it.  It might be to replace

    pat="${${${sdef%%:${tag}*}//\\:/:}//,/ }"

with

    pat="${${${sdef%%:${tag//,/ }*}//\\:/:}}"

but I fear that only Sven knows for sure.  In any case, a qualifier with
a comma in it would interact badly with the file-sort tag, because it will
be rewritten as e.g. *(@,/Om), which is not what you meant.

The workaround is to use reply=(*(@) *(/)) in your style instead.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net