$ hash -d -- -lldpd=/home/bernat/code/deezer/lldpd
$ echo ~-lldpd/README.md
/home/bernat/code/deezer/lldpd/README.md
$ head -n1 ~-lldpd/README.md
lldpd: implementation of IEEE 802.1ab (LLDP)

for link ($MARKPATH/*(N@))  
    hash -d -- -$ link:t =$ link:A 
 

$ pwd
/home/bernat/code/deezer/lldpd/src/lib
$ echo $ (%):-%~ 
~-lldpd/src/lib

bookmark()  
    if (( $# == 0 )); then
        # When no arguments are provided, just display existing
        # bookmarks
        for link in $MARKPATH/*(N@); do
            local markname="$fg[green]$ link:t $reset_color"
            local markpath="$fg[blue]$ link:A $reset_color"
            printf "%-30s -> %s\n" $markname $markpath
        done
    else
        # Otherwise, we may want to add a bookmark or delete an
        # existing one.
        local -a delete
        zparseopts -D d=delete
        if (( $+delete[1] )); then
            # With  -d , we delete an existing bookmark
            command rm $MARKPATH/$1
        else
            # Otherwise, add a bookmark to the current
            # directory. The first argument is the bookmark
            # name.  .  is special and means the bookmark should
            # be named after the current directory.
            local name=$1
            [ $name == "." ] && name=$ PWD:t 
            ln -s $PWD $MARKPATH/$name
        fi
    fi
 

Dynamic named directories Another (more complex) way to achieve the same thing is using dynamic named directories. I was initially using this solution but it is far more complex. This section is only here for historical reason. You can find the complete implementation in my GitHub repository. During file name expansion, a ~ followed by a string in square brackets is provided to the zsh_directory_name() function which will eventually reply with a directory name. This feature can be used to implement directory bookmarks:

$ cd ~[@lldpd]
$ pwd
/home/bernat/code/deezer/lldpd
$ echo ~[@lldpd]/README.md
/home/bernat/code/deezer/lldpd/README.md
$ head -n1 ~[@lldpd]/README.md
lldpd: implementation of IEEE 802.1ab (LLDP)

Like for static named directories, because ~[@lldpd] is substituted during file name expansion, it is possible to use it in any command like a regular directory.

Basic implementation Bookmarks are still kept into a dedicated directory, $MARKPATH and are still symbolic links. Here is how the core feature is implemented:

_bookmark_directory_name()  
    emulate -L zsh #  
    setopt extendedglob
    case $1 in
        n)
            [ [ $2 != ( #b)"@"(?*) ]] && return 1 #  
            typeset -ga reply
            reply=($ $ :-$MARKPATH/$match[1] :A ) #  
            return 0
            ;;
        *)
            return 1
            ;;
    esac
    return 0
 
add-zsh-hook zsh_directory_name _bookmark_directory_name

zsh_directory_name() is a function accepting hooks²: instead of defining it directly, we define another function and register it as a hook with add-zsh-hook. The hook is expected to handle different situations. The first one is to be able to transform a dynamic name into a regular directory name. In this case, the first parameter of the function is n and the second one is the dynamic name. In , the call to emulate will restore the pristine behaviour of Zsh and also ensure that any option set in the scope of the function will not have an impact outside. The function can then be reused safely in another environment. In , we check that the dynamic name starts with @ followed by at least one character. Otherwise, we declare we don t know how to handle it. Another hook will get the chance to do something. (#b) is a globbing flag. It activates backreferences for parenthesised groups. When a match is found, it is stored as an array, $match. In , we build the reply. We could have just returned $MARKPATH/$match[1] but to hide the symbolic link mechanism, we use the A modifier to ask Zsh to resolve symbolic links if possible. Zsh allows nested substitutions. It is therefore possible to use modifiers and flags on anything. $ :-$MARKPATH/$match[1] is a common trick to turn $MARKPATH/$match[1] into a parameter substitution and be able to apply the A modifier on it.

Completion Zsh is also able to ask for completion of a dynamic directory name. In this case, the completion system calls the hook function with c as the first argument.

_bookmark_directory_name()  
    # [...]
    case $1 in
        c)
            # Completion
            local expl
            local -a dirs
            dirs=($MARKPATH/*(N@:t)) #  
            dirs=("@"$ ^dirs ) #  
            _wanted dynamic-dirs expl 'bookmarked directory' compadd -S\] -a dirs
            return
            ;;
        # [...]
    esac
    # [...]
 

First, in , we create a list of possible bookmarks. In *(N@:t), N@ is a glob qualifier. N allows us to not return nothing if there is no match (otherwise, we would get an error) while @ only returns symbolic links. t is a modifier which will remove all leading pathname components. This is equivalent to use basename or $ something##*/ in POSIX shells but it plays nice with glob expressions. In , we just add @ before each bookmark name. If we have b1, b2 and b3 as bookmarks, $ ^dirs expands to b1,b2,b3 and therefore "@"$ ^dirs expands to the (@b1 @b2 @b3) array. The result is then feeded into the completion system.

Prompt expansion Many people put the name of the current directory in their prompt. It would be nice to have the bookmark name instead of the full name when we are below a bookmarked directory. That s also possible!

$ pwd
/home/bernat/code/deezer/lldpd/src/lib
$ echo $ (%):-%~ 
~[@lldpd]/src/lib

The prompt expansion system calls the hook function with d as first argument and the file name to transform.

_bookmark_directory_name()  
    # [...]
    case $1 in
        d)
            local link slink
            local -A links
            for link ($MARKPATH/*(N@))  
                links[$  #link:A $'\0'$ link:A ]=$ link:t  #  
             
            for slink ($ (@On)$ (k)links )  
                link=$ slink#*$'\0'  #  
                if [ [ $2 = ( #b)($ link )( /*) ]]; then
                    typeset -ga reply
                    reply=("@"$ links[$slink]  $(( $  #match[1]  )) )
                    return 0
                fi
             
            return 1
            ;;
        # [...]
    esac
    # [...]
 

OK. This is some black Zsh wizardry. Feel free to skip the explanation. This is a bit complex because we want to substitute the most specific bookmark, hence the need to sort bookmarks by their target lengths. In , the associative array $links is created by iterating on each symbolic link ($link) in the $MARKPATH directory. The goal is to map a target directory with the matching bookmark name. However, we need to iterate on this map from the longest to the shortest key. To achieve that, we prepend each key with its length. Remember, $ link:A is the absolute path with symbolic links resolved. So, $ #link:A is the length of this path. We concatenate the length of the target directory with the target directory name and use $'\0' as a separator because this is the only safe character for this purpose. The result is mapped to the bookmark name. The second loop is an iteration on the keys of the associative array $links (thanks to the use of the k parameter flag in $ (k)links ). Those keys are turned into an array (@ parameter flag) and sorted numerically in descending order (On parameter flag). Since the keys are directory names prefixed by their lengths, the first match will be the longest one. In , we extract the directory name from the key by removing the length and the null character at the beginning. Then, we check if the extracted directory name matches the file name we have been provided. Again, (#b) just activates backreferences. With extended globbing, we can use the or operator, . So, when either the file name matches exactly the directory name or is somewhere deeper, we create the reply which is an array whose first member is the bookmark name and the second member is the untranslated part of the file name.

Easy typing Typing ~[@ is cumbersome. Hopefully, Zsh line editor can be extended with additional bindings. The following snippet will substitute @@ (if typed without a pause) by ~[@:

vbe-insert-bookmark()  
    emulate -L zsh
    LBUFFER=$ LBUFFER "~[@"
 
zle -N vbe-insert-bookmark
bindkey '@@' vbe-insert-bookmark

In combination with the autocd option and completion, it is quite easy to jump to a bookmarked directory.

---

1. For example:

   $ lldpd=/home/bernat/code/deezer/lldpd
   $ echo $lldpd/README.md
   /home/bernat/code/deezer/lldpd/README.md
   $ head -n1 $lldpd/README.md
   lldpd: implementation of IEEE 802.1ab (LLDP)
   

   The drawback is that you don t have a separate namespace for your bookmarks. You can still use a special prefix for that. Also, no prompt expansion.
2. Other functions accepting hooks are chpwd() or precmd().

• CVE triage. I pushed 24 commits to the securitry tracker. I spent more time on this task than usually (see details below).
• I released DLA-143-1 on python-django (fixing 3 CVE). While I expected the update to be quick, my testing revealed that even though the patches applied mostly fine, they did not work as expected. I ended up spending almost 4 hours to properly backport the fixes and the corresponding tests (to ensure that the fixes are working properly).

• #4464: CSV export on tree views is unusable
• #4466: add missing deferral properties on accounts
• #4468: drop abusive reconcile properties on some accounts
• #4469: convert account 6354 into a real non-view account
• #4479: balance non-deferral accounts is broken with non-view parent accounts

• debootstrap-formula
• schroot-formula
• sbuild-formula

sbuild:
  chroots:
    wheezy:
      architectures: [amd64, i386]
      extra_dists:
        - wheezy-backports
        - wheezy-security
      extra_aliases:
        - wheezy-backports
        - stable-security
        - wheezy-security
    jessie:
    [...]

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• A rescue system with /boot and / partitions, both in the 250 GB disk.
• A RAID 1 system of the two 1TB disks, setup in the BIOS of the machine (so the motherboard handles the RAID and the OS is focused in other things).
• Inside the Debian installer, I went to manual partition, then I put my /boot in the 250GB disk (yes, a 2nd /boot there), and then selected the 1TB disk (since the RAID was already made, it appeared a single 1TB disk) as physical device to be encrypted.
• After that, still in the Debian installer, I setup LVM there: configured a volume group, then, two volumes, one for / and the other one for swap.
• Then I saved the changes and go on installing my system.

• I m still not sure if this BIOS RAID ( Fake RAID ) is better than a software RAID or not. I suppose it s better since I delegate in the motherboard to do it, and leave the OS to care about other things (transcode my videos yeah!). But I don t know how to measure performance and which metrics and results should I expect. The disks (cheap disks) are a bit noisy (just a bit! or maybe it s the fan that it s very quiet! poor Laura, never saw/had a luxury machine like this one :)
• I had to install firmware-linux-nonfree in order to properly use the graphics card (Mobility Radeon HD 4225/4250). I have no graphical environment there, only a console, so I was not sure if installing the firmware or not (without the firmware, the letters of the console were bigger, but I just don t mind since I most of the time I log in remotely from my laptop). Then, two questions arised to my ignorant mind:
  1. Do I need the driver for better performance (aka is the graphics card used for rendering/transcoding/showing images and videos in my MediaGoblin site or just when it s needed to display them in local (and subsequently, never)?
  2. If I leave the system like that, and forget about the firmware warning at boot time, can the hardware be damaged by the default (free) driver? (for example, due to fan controlling malfunction or something like that).

• I noticed something strange in my setup. Sometimes, after a system reboot, cryptsetup was not accepting the password to unlock the encrypted disk. And believe me, I was typing it carefully. But when I completely shutdown the computer, unplug the cable, replug the cable, and start again, the password was accepted. The keyboard is USB and this machine does not accept other connection for the keyboard. The keyboard configuration, language and so, was all correct. No Non-ASCII symbols in my password. My password would need to press the same keys in a Spanish and an English keyboard.
• I thought that maybe something in my RAID was failing. I tried to disconnect one of the disks, and see if (1) the bug was solved (no) and (2) the RAID was working (yes). I made the same with the other disk. I was happy that I could reconstruct my RAID when plugging the disk again. But still I had the problem of the password.

• Lua-based maxmemory eviction scripts. (#2319) (This changeset was sponsored by an anonymous client.) Redis typically stores the entire data set in memory, using the operating system's virtual memory facilities if required. However, one can use Redis more like a cache or ring buffer by enabling a "maxmemory policy" where a RAM limit is set and then data is evicted when required based on a predefined algorithm. This change enables entirely custom control over exactly what data to remove from RAM when this maxmemory limit is reached. This is an advantage over the existing policies of, say, removing entire keys based on the existing TTL, Least Recently Used (LRU) or random eviction strategies as it permits bespoke behaviours based on application-specific requirements, crucially without maintaining a private fork of Redis. As an example behaviour of what is possible with this change, to remove the lowest ranked member of an arbitrary sorted set, you could load the following eviction policy script:

  local bestkey = nil
  local bestval = 0
  for s = 1, 5 do
     local key = redis.call("RANDOMKEY")
     local type_ = redis.call("TYPE", key)
     if type_.ok == "zset"
     then
         local tail = redis.call("ZRANGE", key, "0", "0", "WITHSCORES")
         local val = tonumber(tail[2])
         if not bestkey or val < bestval
         then
             bestkey = key
             bestval = val
         end
     end
  end
  if not bestkey
  then
      -- We couldn't find anything to remove, so return an error
      return false
  end
  redis.call("ZREMRANGEBYRANK", bestkey, "0", "0")
  return true
  

• TCP_FASTOPEN support. (#2307) The aim of TCP_FASTOPEN is to eliminate one roundtrip from a TCP conversation by allowing data to be included as part of the SYN segment that initiates the connection. (More info.)

• Support infinitely repeating commands in redis-cli. (#2297)

• Add --failfast option to testsuite runner. (#2290)

• Add a -q (quiet) argument to redis-cli. (#2305)

• Making some Redis Sentinel defaults a little saner. (#2292)

• Add run-parts(8) directories to be executed at various points in the daemon's lifecycle. (e427f8) This is especially useful for loading Lua scripts as they are not persisted across restarts.

• Split out Redis Sentinel into its own package. (#775414, 39f642) This makes it possible to run Sentinel sanely on Debian systems without bespoke scripts, etc.

• Ensure /etc/init.d/redis-server start idempotency with --oknodo (60b7dd) Idempotency in initscripts is especially important given the rise of configuration managment systems.

• Uploaded 3.0.0 RC2 to Debian experimental. (37ac55)

• Re-enabled the testsuite. (7b9ed1)

foo :: Property
foo = property "foo" $
    unlessM (liftIO $ doesFileExist "/etc/foo") $ do
        bar <- liftIO $ readFile "/etc/foo.template"
        ensureProperty $ setupFoo bar

data Property i where
    IProperty :: Desc -> ... -> Info -> Property HasInfo
    SProperty :: Desc -> ... -> Property NoInfo
data HasInfo
data NoInfo
ensureProperty :: Property NoInfo -> Propellor Result

requires :: Property i1 -> Property i2 -> Property ???

class Combine x y r where
    requires :: x -> y -> r

foo  requires  bar

   No instance for (Requires (Property HasInfo) (Property HasInfo) r0)
      arising from a use of  requires'
    The type variable  r0' is ambiguous
    Possible fix: add a type signature that fixes these type variable(s)
    Note: there is a potential instance available:
      instance Requires
                 (Property HasInfo) (Property HasInfo) (Property HasInfo)
        -- Defined at Propellor/Types.hs:167:10

class Combine x y where
    requires :: x -> y -> CombinedType x y

type family CInfo x y
type instance CInfo HasInfo HasInfo = HasInfo
type instance CInfo HasInfo NoInfo = HasInfo
type instance CInfo NoInfo HasInfo = HasInfo
type instance CInfo NoInfo NoInfo = NoInfo
type family CombinedType x y
type instance CombinedType (Property x) (Property y) = Property (CInfo x y)

before :: (IsProp x, Combines y x, IsProp (CombinedType y x)) => x -> y -> CombinedType y x
before x y = (y  requires  x)  describe  (propertyDesc x)
onChange
    :: (Combines (Property x) (Property y))
    => Property x
    => Property y
    => CombinedType (Property x) (Property y)
onChange = -- 6 lines of code omitted
fallback :: (Combines (Property p1) (Property p2)) => Property p1 -> Property p2 -> Property (CInfo p1 p2)
fallback = -- 4 lines of code omitted

propertyList "foos" $ props
    & foo
    & foobar
    ! oldfoo    

Changes in Rcpp version 0.11.4 (2015-01-20)

• Changes in Rcpp API:
  • The ListOf<T> class gains the .attr and .names methods common to other Rcpp vectors.
  • The [dpq]nbinom_mu() scalar functions are now available via the R:: namespace when R 3.1.2 or newer is used.
  • Add an additional test for AIX before attempting to include execinfo.h.
  • Rcpp::stop now supports improved printf-like syntax using the small tinyformat header-only library (following a similar implementation in Rcpp11)
  • Pairlist objects are now protected via an additional Shield<> as suggested by Martin Morgan on the rcpp-devel list.
  • Sorting is now prohibited at compile time for objects of type List, RawVector and ExpressionVector.
  • Vectors now have a Vector::const_iterator that is 'const correct' thanks to fix by Romain following a bug report in rcpp-devel by Martyn Plummer.
  • The mean() sugar function now uses a more robust two-pass method, and new unit tests for mean() were added at the same time.
  • The mean() and var() functions now support all core vector types.
  • The setequal() sugar function has been corrected via suggestion by Qiang Kou following a bug report by S ren H jsgaard.
  • The macros major, minor, and makedev no longer leak in from the (Linux) system header sys/sysmacros.h.
  • The push_front() string function was corrected.
• Changes in Rcpp Attributes:
  • Only look for plugins in the package's namespace (rather than entire search path).
  • Also scan header files for definitions of functions to be considerd by Attributes.
  • Correct the regular expression for source files which are scanned.
• Changes in Rcpp unit tests
  • Added a new binary test which will load a pre-built package to ensure that the Application Binary Interface (ABI) did not change; this test will (mostly or) only run at Travis where we have reasonable control over the platform running the test and can provide a binary.
  • New unit tests for sugar functions mean, setequal and var were added as noted above.
• Changes in Rcpp Examples:
  • For the (old) examples ConvolveBenchmarks and OpenMP, the respective Makefile was renamed to GNUmakefile to please R CMD check as well as the CRAN Maintainers.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

• A scheme to get labs and college engineering/computer science departments off proprietary software by helping them identify relevant free software (writing it if necessary.) and helping them transition to it. Similarly getting curricula away from textbooks that use proprietary software by rewriting exercises to use free equivalents.
• A series of videos for self-instruction kind of like Khan Academy but geared to the challenges of being used in places where there might not be a net connection or even a trained teacher.
• The Vidyut tablet. A very low cost (~5000 Rupees) ARM-based netbook that runs Linux or Android software. You may have heard about earlier plans for a cheap tablet like this. Vidyut is the next generation correcting some flaws in previous attempts. Not only the software but the hardware is free too. It is currently running a stripped down version of Ubuntu but there was a request to port it to Debian and I'm happy to report several Debian users have accepted the challenge.

• Some people said it is hard to find concise, easily digestible information about what Debian can do. (I.e. Can I surf the web? Can I play a certain game? etc.) Debian-IN's web presence in particular needs a lot of improvement. We should also consider other channels such as a facebook page. A volunteer stepped up to look into these issues.
• Along these lines it was felt that we cannot just wait for people to come to us, we should do more outreach. I pointed out that one group that we need to reach out more to is the Debian Project at large. We need to do more publicity in debian-project, DWN, Planet etc. to let everyone know whats going on in India. I also felt that we have a strong base amongst CS/engineering students but should do more to attract other demographics.
• Debian events have suffered from organizational problems. Partly this is because the people involved are not professional event planners. They are learning how to do it which is an ongoing process and execution is improving with each iteration so no worries there but problems also arise because Debian-IN is dependent on other entities for many things and those entities do not always have, shall we say, the same sense of urgency. Therefore we need legal standing of our own for accepting donations, inviting foreign guests etc. This doesn't necessarily have to be a separate organization. Affiliating with an existing group is an option providing they share our ideology. Swathanthra Malayalam Computing was one suggestion.
• There is still not much Debian presence in the North and East of India. (Which includes large cities like Delhi and Kolkata.) Unfortunately until we can find volunteers in those areas to take the lead on organizing something there is not a lot we can do to rectify the situation.
• We must have Debian-IN t-shirts.

The concept is based on the idea that we all have a personal narrative that shapes our view of the world and ourselves. But sometimes our inner voice doesn t get it completely right. Some researchers believe that by writing and then editing our own stories, we can change our perceptions of ourselves and identify obstacles that stand in the way of better health. It may sound like self-help nonsense, but research suggests the effects are real. Students who had been prompted to change their personal stories improved their grade-point averages and were less likely to drop out over the next year than the students who received no information. In the control group, which had received no advice about grades, 20 percent of the students had dropped out within a year. But in the intervention group, only 1 student or just 5 percent dropped out.

Now I am 79. I ve written many hundreds of essays, 10 times that number of misbegotten drafts both early and late, and I begin to understand that failure is its own reward. It is in the effort to close the distance between the work imagined and the work achieved wherein it is to be found that the ceaseless labor is the freedom of play, that what s at stake isn t a reflection in the mirror of fame but the escape from the prison of the self. T. H. White, the British naturalist turned novelist to write The Once and Future King, calls upon the druid Merlyn to teach the lesson to the young prince Arthur: You may grow old and trembling in your anatomies, you may lie awake at night listening to the disorder of your veins, you may miss your only love, you may see the world about you devastated by evil lunatics, or know your honour trampled in the sewers of baser minds. There is only one thing for it then to learn. Learn why the world wags and what wags it. That is the only thing which the mind can never exhaust, never alienate, never be tortured by, never fear or distrust, and never dream of regretting.

The arrival fallacy is about seeking a life from which one can look with a complacent equanimity upon the rest of reality, without yearning. It is an ideal of a life that is defined primarily by blindness to itself. You yearn while you see your life as others see it, until you arrive at a situation where you can disappear into the broader background, and see comfortably without being seen discomfittingly, especially by yourself. Once you re there, the yearning stops, so the theory goes. Of course it is a laughably bad theory.

Everyone s first instinct is to put their hands or legs down first. That s the worst thing you can do: you will break something. The pointy parts of your body hurt elbows, knees, hips, ankles. Put your fists under your chin, and bring your elbows together. Keep your chin tucked in to your chest to protect your head. The best point of impact is the back of the shoulder and your back. If you dive out directly onto your shoulder you ll break it.

Shea Strauss.

Georges Braque has said that out of limited means, new forms emerge. I say, we find out what we will do by knowing what we will not do. And so, if your heart is set on 8 10 platinum landscapes in misty southern terrains, work your way through those who inspire you, ride their bus route and damn those who would say you are merely repeating what has been done before. Wait for the months and years to pass and soon your differences will begin to appear with clarity and intelligence, when your originality will become visible, even the works from those very first years of trepidation when everything you did seemed so done before.

And for the bulging demographic of baby boomers growing old, Beskind has this advice: Embrace change and design for it.

cert-sync /path/to/ca-bundle.crt

cert-sync /etc/ssl/certs/ca-certificates.crt

cert-sync /etc/pki/tls/certs/ca-bundle.crt

• Ben Hutchings (for his first month!).
• Holger Levsen
• Rapha l Hertzog
• Thorsten Alteholz

• Gold sponsors:
• The Positive Internet
• Silver sponsors:
• AD&D David Ayers IntarS Austria
• Blablacar
• Domeneshop AS
• Evolix
• Trollweb Solutions
• Universit Lille 3
• Bronze sponsors:
• Bitfolk LTD
• Daevel SARL
• FOSSter
• Freeside Internet Service
• Intevation GmbH
• Linuxhotel GmbH
• Megaspace Internet Services GmbH
• MyTux
• Nantes M tropole
• Offensive Security
• Seznam.cz, a.s.

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Given a .buildinfo file, it first finds a timestamp of Debian Sid from snapshot.debian.org which contains the requested packages in their exact versions. It then runs sbuild with the right architecture as given by the .buildinfo file and the right base system to upgrade from, as given by the version of the base-files package version in the .buildinfo file. Using two hooks it will install the right package versions and verify that the installed packages are in the right version before the build starts.

* h01ger is very happy to see again and again how this is a nice
         learning circle...! i've learned a whole lot here too... in
         just 3 months... and its going on...!