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» A git hook to prevent pushes with untracked source files

Fri, 08/08/2014 - 13:40

Hey all,

do you know this: You work on something locally in git, ensure everything compiles and the tests pass, then commit and hit git push.What could possibly go wrong at that point, eh? Well, far too often I forgot to git add some new source file. Best-case I’ll notice this directly, worst-case I’ll see my CI complaining. But, like yesterday in kdev-clang, I might be afk at that point and someone else will have to revert my change and I’ll have to fix it up the day after, polluting the git history while at it…

Thanks to some simple shell scripting and the powerful git hook architecture, it is pretty simple to protect oneself against such issues:

  1. #!/bin/sh
  3. #
  4. # A hook script to verify that a push is not done with untracked source file
  5. #
  6. # To use it, either symlink this script to $your-git-clone/.git/hooks/pre-push
  7. # or include it in your existing pre-push script.
  8. #
  10. # Perl-style regular expression which limits the files we interpret as source files.
  11. # The default pattern here excludes CMakeLists.txt files and any .h/.cpp/.cmake files.
  12. # Extend/adapt this to your needs. Alternatively, set the pattern in your repo via:
  13. # git config hooks.prepush.sourcepattern "$your-pattern"
  14. pattern=$(git config --get hooks.prepush.sourcepattern)
  15. if [ -z "$pattern" ]; then
  16. pattern="(?:(?:^|/)CMakeLists\.txt|\.h|\.cpp|\.cmake)$"
  17. fi
  19. files=$(git status -u --porcelain --no-column | sed "s/^?? //" | grep -P "$pattern")
  20. if [ -z "$files" ]; then
  21. exit 0
  22. fi
  24. echo
  25. echo "ERROR: Preventing push with untracked source files:"
  26. echo
  27. echo "$files" | sed "s/^/ /"
  28. echo
  29. echo "Either include these files in your commits, add them to .gitignore"
  30. echo "or stash them with git stash -u."
  31. echo
  32. exit 1

Note: The last version of the above code can be found on GitHub: pre-push-check-untracked

When you then try to push with some untracked source files, i.e. files matched by the regex pattern which can be configured via git config hooks.prepush.sourcepattern, you’ll see output like this:

  1. # to show the current status, note the untracked bar file which is not included as a source file
  2. $ git status
  3. On branch master
  4. Your branch is up-to-date with 'origin/master'.
  6. Untracked files:
  7. (use "git add <file>..." to include in what will be committed)
  9. CMakeLists.txt
  10. bar
  11. foo/
  13. nothing added to commit but untracked files present (use "git add" to track)
  15. # now try to push something
  17. $ git push
  19. ERROR: Preventing push with untracked source files:
  21. CMakeLists.txt
  22. foo/asdf.h
  24. Either include these files in your commits, add them to .gitignore
  25. or stash them with git stash -u.
  27. error: failed to push some refs to '/tmp/repo'

Happy hacking!

» Tracking Memory Consumption Using Pmap

Fri, 03/16/2012 - 14:55

Massif is a really nifty tool which is very powerful, especially paired with my visualizer. The caveat of course is that it slows down the application considerably, I’ve seen anything up to a factor of 100… I see no alternative to Massif when it comes to investigating where your memory problems come from. But if you just want to see whether you have a problem at all, tracking the total memory consumption should suffice.

A few days ago, I came across pmap on Stack Overflow, which makes it easy to track the RSS memory consumption of an application using the -x switch. Of course I had to write some bash magic to automate this process and visualize the data using Gnuplot! Behold:

memory consumption of PhantomJS
memory consumption of a PhantomJS script over ~30min

It’s simple, really: $(pidof myapp).

The default timeout is ~1s between snapshots, you can pass a different timeout as second parameter. Bash’s sleep can also take float numbers such as 0.1 to get more snapshots for fast-running apps.

You can also run mem.log.$(pidof myapp) while you are still tracking the memory. The gnuplot window that appears allows you to update the data intermittently, to zoom in and to create images such as the above.

Note: This kind of memory usage tracking costs nearly nothing, your application continues to work at full speed. Also be aware that this just shows the RSS memory consumption. Massif will always give you better, more detailed and accurate results. Still, I think this should already give you an idea on how your application behaves. If the graph goes up and up, you probably got a memory leak! Then it’s time to run Memcheck and/or Massif to find the issue and fix it!

You can find the most-recent version on GitHub:

  1. #!/bin/bash
  3. #
  4. # track memory of given application, identified by PID,
  5. # using pmap -x, to show RSS and Dirty memory usage.
  6. #
  7. # visualization can later on be done with the
  8. # script.
  9. #
  11. pid=$1
  12. sleep=$2;
  14. if [[ "$sleep" == "" ]]; then
  15. sleep=1
  16. fi
  18. if [[ "$(ps -p $pid | grep $pid)" == "" ]]; then
  19. echo "cannot find program with pid $pid"
  20. echo " PID [SLEEP_TIMEOUT]"
  21. echo
  22. echo "example: \$(pidof someapp) 0.1"
  23. exit
  24. fi
  26. logfile=mem.log.$pid
  28. echo "# $(ps -o command= -p $pid)" > $logfile
  29. echo "# $sleep" >> $logfile
  31. cat $logfile
  33. while [[ "$(ps -p $pid | grep $pid)" != "" ]]; do
  34. echo "snapshot " $pid
  35. pmap -x $pid | tail -n1 >> $logfile
  36. echo "$sleep"
  37. sleep $sleep;
  38. done
  40. echo "done tracking, visualizing"
  41. $(dirname $0)/ "$logfile"

You can find the most-recent version on GitHub:

  1. #!/bin/bash
  3. #
  4. # visualize memory consumption over time
  5. # as recorded by pmap /
  6. # script
  7. #
  9. logfile=$1
  11. if [ ! -f "$logfile" ]; then
  12. echo "cannot find memory logfile: $1"
  13. echo
  14. echo "usage: LOGFILE"
  15. echo
  16. echo "example: mem.log.12345"
  17. exit
  18. fi
  20. title=$(head -n1 "$logfile")
  21. timeout=$(head -n2 "$logfile" | tail -n1)
  23. title=${title/\# /}
  24. timeout=${timeout/\# /}
  26. # total:
  27. # '$logfile' using 3 w lines title 'Kbytes', \
  29. gnuplot -p -e "
  30. set title '$title';
  31. set xlabel 'snapshot ~${timeout}s';
  32. set ylabel 'memory consumption in kB';
  33. set key bottom right;
  34. plot \
  35. '$logfile' using 4 w lines title 'RSS' lt 1, \
  36. '$logfile' using 4 smooth bezier w lines title 'RSS (smooth)' lt 7, \
  37. '$logfile' using 5 w lines title 'Dirty' lt 2, \
  38. '$logfile' using 5 smooth bezier w lines title 'Dirty (smooth)' lt 3;
  39. ";

The above is nice, but I’m wondering on whether one should not add this kind of utility to ksysguard: It already allows you to track the total memory consumption of your system, yet I did not find a way to just track a single application and visualize it’s memory consumption.

» Shell helper: running KDE unit tests (ctests) the easy way

Thu, 03/26/2009 - 03:09

Unit tests are in my eyes a very important part of programming. KDE uses them, KDevelop does - the PHP plugin I help writing does as well. cmake comes with a ctest program which does quite well to give you a quick glance on which test suite you just broke with your new fance feature :)

But I am very dissatisfied with it. Right now I usually do the following

  1. # lets assume I'm in the source directory
  2. cb && ctest
  3. # look for failed test suites
  4. cd $failed_test_suite_path
  5. ./$ | less
  6. # search for FAIL
  7. cs
  8. cd $to_whereever_I_was_before

That’s pretty much for just running a test. Especially all that cding and lessing became very tedious. Tedious is good, because I eventually fix it:

introducing kdetest

I wrote a bash function (with autocompletion!!!) called kdetest. Calling it without any parameter will run all test suites and gives a nice report of failed functions at the end. Here’s an example (run via cs php && kdetest).

  1. kdetest
  2. # ... lots of test output
  4. --- ALL PASSED TESTS ---
  5. ...
  6. PASS : Php::TestCompletion::implementMethods()
  7. PASS : Php::TestCompletion::inArray()
  8. PASS : Php::TestCompletion::cleanupTestCase()
  10. 143 passed tests in total
  12. --- ALL FAILED TESTS ---
  13. FAIL! : Php::TestCompletion::newExtends() Compared values are not the same
  14. FAIL! : Php::TestCompletion::updateExtends() '! forbiddenIdentifiers.contains(item->declaration()->identifier().toString())' returned FALSE. ()
  15. FAIL! : Php::TestCompletion::updateExtends() '! forbiddenIdentifiers.contains(item->declaration()->identifier().toString())' returned FALSE. ()
  16. FAIL! : Php::TestCompletion::updateExtends() Compared values are not the same
  17. FAIL! : Php::TestCompletion::newImplements() Compared values are not the same
  18. FAIL! : Php::TestCompletion::updateImplements() Compared values are not the same
  20. 6 failed tests in total
  • kdetest, i.e. without any arguments runs all tests in this directory and below
  • kdetest path/to/ ... runs that test suite only, ... can by any argument the test suite accepts.

kdetest comes with full support for autocompletion of tests and functions, for example:

  1. milian@odin:~/projects/kde4/php$ kdetest TABTAB
  2. completion/tests/ duchain/tests/ parser/test/
  3. duchain/tests/ duchain/tests/
  4. milian@odin:~/projects/kde4/php$ kdetest duchain/tests/ TABTAB
  5. classAndConstWithSameName classSelf interfaceExtendsMultiple staticMemberFunctionCall
  6. classAndFunctionWithSameName constAndVariableWithSameName memberFunctionCall staticMemberVariable
  7. classConstant constant memberFunctionInString variable
  8. classExtends constantInClassMember memberVariable variableTwoDeclarations
  9. classImplements functionAndClassWithSameName memberVarInString variableTwoDeclarationsInFunction
  10. classImplementsMultiple functionCall newObject varInString
  11. classParent interfaceExtends objectWithClassName
the code

You can find the code below, or you can obtain the most up-to-date version on github. Just head over to my shell-helpers repo and peek into the bash_setup_kde4_programming file.

» Attack of the shell helpers

Mon, 03/02/2009 - 02:46

Everyone who uses the command line regularly has a bunch of (at least for him) useful helper scripts. I now took the liberty to put mine on github for general consumption.

You can find them at:

Some of these might be more useful than others, you decide :) Personally, I can’t live without the following:

a shortcut to update your Debian system with one command - no questions asked
opens a given URL in an already opened browser instance or starts a new browser session. Not only one browser is checked. I use it because firefox is slow to start and konqueror is blazingly fast to start. But when firefox is already open I want to use that.
shortcut for fast error checking in your Xorg log
makes KDE4 Klipper contents available on the CLI (read and write access!)

shortcut to start a GDB session: debug APP APP_ARGS is all you have to do. Its basically the same as doing:

  1. $ gdb APP
  2. > run APP_ARGS

» Download script for Ebooks

Sat, 11/08/2008 - 17:28

After a long period of silence I present you the following bash script for downloading books from This is not a way to circumvent their login mechanisms, you will need proper rights to download books. But many students in Germany get free access to those ebooks via their universities. I for example study at the FU Berlin and put the script in my Zedat home folder and start the download process via SSH from home. Afterwards I download the tarball to my home system.

Read on for the script.

» Access klipper clipboard on CLI under KDE4

Wed, 08/13/2008 - 23:12

NOTE: find most recent version on github:

Here’s a little script you can save in your path and do things like

  1. # paste current clipboard into file
  2. clipboard > "some_file"
  3. # copy some file into clipboard
  4. cat "some_file" | clipboard

Actually I find it rather useful so I thought I should share it.

  1. #!/bin/bash
  3. # Access your KDE 4 klipper on the command line
  4. # usage:
  5. # ./clipboard
  6. # will output current contents of klipper
  7. # echo "foobar" | ./clipboard
  8. # will put "foobar" into your clipboard/klipper
  10. # check for stdin
  11. if ! tty -s && stdin=$(</dev/stdin) && [[ "$stdin" ]]; then
  12. # get the rest of stdin
  13. stdin=$stdin$'\n'$(cat)
  14. # oh, nice - user input! we set that as current
  15. # clipboard content
  16. qdbus org.kde.klipper /klipper setClipboardContents "$stdin"
  17. exit
  18. fi
  20. # if we reach this point no user input was given and we
  21. # print out the current contents of the clipboard
  22. qdbus org.kde.klipper /klipper getClipboardContents

As usually, save the file (attached below) in your $PATH and make it executable.

PS: Thanks to Martin Vidner for his article on D-BUS btw. - it gave me the proper dbus commands. PPS: Thanks the the various comments below!

» How to generate proper DIN A4 sized plots with Gnuplot

Fri, 05/16/2008 - 21:04

I’ve had a major annoyance today: The plot generated by gnuplot looked good inside the wxt terminal but I simply couldn’t get a proper fullsized DIN A4 postscript exported. This is how I’ve done it now:

  1. Inside gnuplot:
    1. set size ratio 0.71 # this is the ratio of a DIN A4 page (21/29.7)
    2. set terminal postscript enhanced landscape "Arial" 9 # you can change landscape to portrait and the fontname and -size
    3. set output '' # this is your export file
    4. replot # or put your custom plot command here
  2. In a shell:
    1. ps2ps -sPAGESIZE=a4
  3. Now you can simply print `` from within KGhostView for example. Have fun!

» mp3dump take two - better audio quality

Sat, 03/29/2008 - 16:29

So just yesterday I’ve published a bash script which rips the audio stream of Flash Videos (*.flv) to mp3 format. It’s nice, fast and imo all-purpose. But I didn’t like the audio quality. Thus below you can find a second version of the script which is using mplayer and lame instead of ffmpeg. Usage and behaviour should be pretty much the same. Only the audio quality should be better on cost of a bit more computing.

Since it relies on the fact that the input *.flv video already uses MP3 encoding for its audio stream this might not work for every flash file! Youtube works just fine though. You can find the script after the break, it’s also attached below. For usage / installation / more information read the old article.

If you wonder why I reencode the audiodump with lame: The dumped mp3 file is considered by most (all?) audio players to be ~10x the length. A five minute video gets a 45 minute audio dumpfile. It plays fine but seeking is a mess. Reencoding fixes this. If you know an alternative which does not require reencoding or is generally faster - please drop a comment!

» mp3dump: Rip the audio stream of a Flash video to MP3

Fri, 03/28/2008 - 00:03

UPDATE: Also check out mp3dump part 2

On some undefined occasion you might want to dump the audio stream of a flash file. This is how you do it:

  1. Get the *.flv, e.g. visit youtube with Konqueror and check /tmp for a file like FlashV5SQLt - this is your FLV.
  2. Install some dependencies: ffmpeg is required, mp3info and ecasound are optional but strongly recommended.
  3. Download the script below (it’s attached!) and save it inside your $PATH, remember how you’ve called it!
  4. I’ve saved the script inside ~/.bin which is inside my $PATH so all I have to do now is running it:

    mp3dump FlashV5SQLt "Foo Bar" "All Your Base Are Belong To Us"

    This would rip the audio stream of FlashV5SQLt to a file named Foo Bar - All Your Base Are Belong To Us.mp3 - with emulated stereo sound and basic MP3 tags (artist and title). Coolio!

» Reinstall Nvidia Driver

Sat, 02/09/2008 - 03:41

For those of you, who use the original NVIDIA display driver and have to reinstall it with every kernel update: Here is a little bashscript for your convenience.

  1. #!/bin/bash
  2. sudo /etc/init.d/kdm stop
  3. sudo chvt 1
  4. sudo sh ~/Downloads/NVIDIA-Linux-x86-*.run --ui='none' -aNq
  5. sudo /etc/init.d/kdm start
  6. sudo chvt 7

Save it e.g. as ~/.bin/, make it executable (chmod +x ~/.bin/ Then put your NVIDIA driver (only the newest version please) into ~/Downloads/ (or change the path above). Now run your script.

Attention: Save all your work, since kdm will be stopped! You’ll lose all unsaved work!