zsh spinning for ages when I hit tab on directory

zsh spinning for ages when I hit tab on directory

[Markus Trippelsdorf]

Zsh is busy spinning for minutes when I hit tab at the end of an
directory. For example consider:
~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
man1 % l
total 1748
drwxr-xr-x 2 root     72 Nov  8 13:37 .
drwxr-xr-x 4 root     28 May 27 15:33 ..
-rw-r--r-- 1 root  42888 Nov  8 13:37 cpp.1
-rw-r--r-- 1 root 824844 Nov  8 13:37 g++.1
-rw-r--r-- 1 root 824844 Nov  8 13:37 gcc.1
-rw-r--r-- 1 root  24554 Nov  8 13:37 gcov.1

When position the cursor after the man1/ of 
~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
and hit tab, zsh starts spinning:

 96.79%  libzsh-4.3.12.so   [.] 0x7185f
  0.12%  [kernel]           [k] handle_irq_event_percpu
  0.07%  libFLAC.so.8.2.0   [.] FLAC__bitreader_read_rice_signed_block  
...

And after a few minutes it prints:
---- no match for: `external command', `executable file or directory',
`builtin command', `shell function', `alias', `suffix alias', `reserved
word', `job', `parameter', or `corrections'

Any ideas how to fix this behavior?
Thanks.
-- 
Markus

Re: zsh spinning for ages when I hit tab on directory

[Markus Trippelsdorf]

On 2011.11.08 at 14:10 +0100, Markus Trippelsdorf wrote:
> Zsh is busy spinning for minutes when I hit tab at the end of an
> directory. For example consider:
> ~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
> man1 % l
> total 1748
> drwxr-xr-x 2 root     72 Nov  8 13:37 .
> drwxr-xr-x 4 root     28 May 27 15:33 ..
> -rw-r--r-- 1 root  42888 Nov  8 13:37 cpp.1
> -rw-r--r-- 1 root 824844 Nov  8 13:37 g++.1
> -rw-r--r-- 1 root 824844 Nov  8 13:37 gcc.1
> -rw-r--r-- 1 root  24554 Nov  8 13:37 gcov.1
> 
> When position the cursor after the man1/ of 
> ~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
> and hit tab, zsh starts spinning:
> 
>  96.79%  libzsh-4.3.12.so   [.] 0x7185f
>   0.12%  [kernel]           [k] handle_irq_event_percpu
>   0.07%  libFLAC.so.8.2.0   [.] FLAC__bitreader_read_rice_signed_block  

When I zoom into zsh with "perf top" I see:
 69.44%  zsh              [.] patmatch
 14.15%  zsh              [.] charrefinc 
  9.44%  zsh              [.] charnext
  6.66%  zsh              [.] charref 
...

-- 
Markus

Re: zsh spinning for ages when I hit tab on directory

[Markus Trippelsdorf]

On 2011.11.08 at 14:58 +0100, Markus Trippelsdorf wrote:
> On 2011.11.08 at 14:10 +0100, Markus Trippelsdorf wrote:
> > Zsh is busy spinning for minutes when I hit tab at the end of an
> > directory. For example consider:
> > ~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
> > man1 % l
> > total 1748
> > drwxr-xr-x 2 root     72 Nov  8 13:37 .
> > drwxr-xr-x 4 root     28 May 27 15:33 ..
> > -rw-r--r-- 1 root  42888 Nov  8 13:37 cpp.1
> > -rw-r--r-- 1 root 824844 Nov  8 13:37 g++.1
> > -rw-r--r-- 1 root 824844 Nov  8 13:37 gcc.1
> > -rw-r--r-- 1 root  24554 Nov  8 13:37 gcov.1
> > 
> > When position the cursor after the man1/ of 
> > ~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
> > and hit tab, zsh starts spinning:
> > 
> >  96.79%  libzsh-4.3.12.so   [.] 0x7185f
> >   0.12%  [kernel]           [k] handle_irq_event_percpu
> >   0.07%  libFLAC.so.8.2.0   [.] FLAC__bitreader_read_rice_signed_block  
> 
> When I zoom into zsh with "perf top" I see:
>  69.44%  zsh              [.] patmatch
>  14.15%  zsh              [.] charrefinc 
>   9.44%  zsh              [.] charnext
>   6.66%  zsh              [.] charref 

Ah, it's the following lines in my .zshrc that are responsible:

zstyle ':completion:::::' completer _complete _approximate                                                                                           
zstyle -e ':completion:*:approximate:*' max-errors 'reply=( $(( ($#PREFIX+$#SUFFIX)/3 )) )'                                                          
zstyle ':completion:*:corrections' format '%B%d (errors: %e)%b' 

When I comment out the max-errors zstyle, zsh no longer hangs.

So the next question is, how can I get the same behavior as before, but
without the long hangs?

-- 
Markus

Re: zsh spinning for ages when I hit tab on directory

[Bart Schaefer]

On Nov 8,  3:21pm, Markus Trippelsdorf wrote:
} Subject: Re: zsh spinning for ages when I hit tab on directory
}
} > > When position the cursor after the man1/ of 
} > > ~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
} > > and hit tab, zsh starts spinning:
} 
} zstyle ':completion:::::' completer _complete _approximate
} zstyle -e ':completion:*:approximate:*' max-errors 'reply=( $(( ($#PREFIX+$#SUFFIX)/3 )) )'
} zstyle ':completion:*:corrections' format '%B%d (errors: %e)%b'
} 
} When I comment out the max-errors zstyle, zsh no longer hangs.
} 
} So the next question is, how can I get the same behavior as before, but
} without the long hangs?

You're computing max-errors based on the length of the entire path, but
the effect of correction is applied to each individual component, so
you're allowing 18 corrections per filename in man1/ with the above.

Try changing to something like

zstyle -e ':completion:*:approximate:*' \
	max-errors 'reply=( $(( ($#PREFIX:t+$#SUFFIX:h)/3 )) )'

although that (and your original) allows no corrections unless there
are at least 6 characters already in the current word, so you might
want to use e.g. ($#PREFIX:t+2) or ($#PREFIX:t < 3 ? 3 : $#PREFIX:t).

Re: zsh spinning for ages when I hit tab on directory

[Mikael Magnusson]

On 8 November 2011 16:13, Bart Schaefer <schaefer@brasslantern.com> wrote:
> On Nov 8,  3:21pm, Markus Trippelsdorf wrote:
> } Subject: Re: zsh spinning for ages when I hit tab on directory
> }
> } > > When position the cursor after the man1/ of
> } > > ~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
> } > > and hit tab, zsh starts spinning:
> }
> } zstyle ':completion:::::' completer _complete _approximate
> } zstyle -e ':completion:*:approximate:*' max-errors 'reply=( $(( ($#PREFIX+$#SUFFIX)/3 )) )'
> } zstyle ':completion:*:corrections' format '%B%d (errors: %e)%b'
> }
> } When I comment out the max-errors zstyle, zsh no longer hangs.
> }
> } So the next question is, how can I get the same behavior as before, but
> } without the long hangs?
>
> You're computing max-errors based on the length of the entire path, but
> the effect of correction is applied to each individual component, so
> you're allowing 18 corrections per filename in man1/ with the above.
>
> Try changing to something like
>
> zstyle -e ':completion:*:approximate:*' \
>        max-errors 'reply=( $(( ($#PREFIX:t+$#SUFFIX:h)/3 )) )'
>
> although that (and your original) allows no corrections unless there
> are at least 6 characters already in the current word, so you might
> want to use e.g. ($#PREFIX:t+2) or ($#PREFIX:t < 3 ? 3 : $#PREFIX:t).

You might also want to set this style:
zstyle ':completion:*' accept-exact-dirs 'yes'
Then zsh will not attempt to change segments that already match a dir
when a later doesn't exist.

-- 
Mikael Magnusson

Re: zsh spinning for ages when I hit tab on directory

[Markus Trippelsdorf]

On 2011.11.08 at 07:13 -0800, Bart Schaefer wrote:
> On Nov 8,  3:21pm, Markus Trippelsdorf wrote:
> } Subject: Re: zsh spinning for ages when I hit tab on directory
> }
> } > > When position the cursor after the man1/ of 
> } > > ~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
> } > > and hit tab, zsh starts spinning:
> } 
> } zstyle ':completion:::::' completer _complete _approximate
> } zstyle -e ':completion:*:approximate:*' max-errors 'reply=( $(( ($#PREFIX+$#SUFFIX)/3 )) )'
> } zstyle ':completion:*:corrections' format '%B%d (errors: %e)%b'
> } 
> } When I comment out the max-errors zstyle, zsh no longer hangs.
> } 
> } So the next question is, how can I get the same behavior as before, but
> } without the long hangs?
> 
> You're computing max-errors based on the length of the entire path, but
> the effect of correction is applied to each individual component, so
> you're allowing 18 corrections per filename in man1/ with the above.
> 
> Try changing to something like
> 
> zstyle -e ':completion:*:approximate:*' \
> 	max-errors 'reply=( $(( ($#PREFIX:t+$#SUFFIX:h)/3 )) )'
> 
> although that (and your original) allows no corrections unless there
> are at least 6 characters already in the current word, so you might
> want to use e.g. ($#PREFIX:t+2) or ($#PREFIX:t < 3 ? 3 : $#PREFIX:t).

Thanks Bart. This fixes the problem. 
BTW I copied the lines from the "From bash to Z Shell" book.

-- 
Markus

Re: zsh spinning for ages when I hit tab on directory

[Bart Schaefer]

On Nov 8,  4:35pm, Markus Trippelsdorf wrote:
} Subject: Re: zsh spinning for ages when I hit tab on directory
}
} > } zstyle ':completion:::::' completer _complete _approximate
} > } zstyle -e ':completion:*:approximate:*' max-errors 'reply=( $(( ($#PREFIX+$#SUFFIX)/3 )) )'
} > 
} > zstyle -e ':completion:*:approximate:*' \
} > 	max-errors 'reply=( $(( ($#PREFIX:t+$#SUFFIX:h)/3 )) )'
} 
} Thanks Bart. This fixes the problem. 
} BTW I copied the lines from the "From bash to Z Shell" book.

Ah, yes, well, examples in books tend to illustrate isolated concepts.
It's a perfectly good example of how "zstyle -e" works, which in spite
of it being introduced in the section on _approximate is really what
the authors were getting at.

Also it works perfectly well as long as you don't type a really long
path to a directory filled with a lot of files. :-)

[This problem didn't occur to me as a technical reviewer of the book,
either, so ... accept our collective apologies?]