Monthly Archives: November 2017

Upgrading OpenWRT to LEDE

A bit late, but I wanted to upgrade OpenWRT 15.05 to LEDE 17.01.4.

It worked perfectly for my WDR 4900. The OpenWRT-to-LEDE-rebranding caused no problems.

I basically followed my own upgrade instuctions.
I also took advantage of adding files and folders to /etc/sysupgrade.conf. Those where automatically kept during the upgrade, which is nice.

Conclusion (based on one successful upgrade): if you are an old OpenWRT fan there is no reason to fear LEDE and wait for a new OpenWRT release before upgrading.

Syncthing v0.14.40, Raspberry Pi, 100% CPU

I think Syncthing is an amazing piece of software, but I ran into problem last week.

I have a library of 10 different folders, 120000 files, 42000 directories and 428GB of data.

I thought that was a little bit too much for my RPi V1 (Syncthing 0.14.40, Arch Linux), because it constantly ran at 100%. I raised Rescan Interval to several hours (so it would finish before staring over).

After startup it took about 10-15 min to get the web GUI up, and about an hour to scan all folders for the first time. Well, that is ok, but after that it still constantly used 100% CPU despite all folders were “up to date”.

It turned out it crashed and started over. I found panic logs in .config/syncthing and error messages in ./config/syncthing/index-v0.14.0.db/LOG.

Some errors indicated Bad Magic Number and Checksum Corruption. The usual reason for this seems to be hardware problem (!?!).

I upgraded my RPi V1 to an RPi V2, with little success. Then I found that I had similar problems on another RPi V2. So after shutting down Syncthing I tried the quite scary:

  $ syncthing -reset-database      ( does not start syncthing )      
  $ syncthing                      ( start syncthing )

After several hours of scanning everything seems to work perfectly!
Let us see how long that lasts.

Eee in 2017

I came up with a possible use for my Asus EeePC 701! A challenge is to find a Linux distribution that works well with it: Lubuntu 16.04 LTS Alternative 32-bit seems good.

Lubuntu 16.04.3 is released, but for the moment I got 16.04.1 with the alternative download. After installation about 1200MB was available (I created no swap, despite warnings, since I have 2BG RAM) on my 4GB SSD.

It turned out the full upgrade (to 16.04.3) requried too much temporary space and filled up my drive. You can do two things to prevent this:

  • Mount /var/cache/apt on a USB drive while upgrading
  • Uninstall packages

When it comes to finding unnecessary packages its up to you. I uninstalled cups (no need to print), abiword (no need to write documents), gnumeric (no need to do excel-work) and many fonts (mostly thai and japanese).

Developer lost in Windows

Admittedly, I am not a Microsoft fan, but Windows is a quite fine operating system nowadays. This article is not about complaining with Windows.

This article is also not about native Windows development for Windows. That is, if you use Windows, Visual Studio and C# (or other languages native to Windows development) to produce software targeting Windows, this article is not for you.

I and other programmers use Linux, OS X or possibly BSD to develop software meant to be OS independent. Our core tools are perhaps bash and a terminal emulator. We use tools like grep, head, tail, curl, iconv, sed, bc, emacs, vim, ssh, nc, git or svn on a daily basis (without them we are in a foreign land not understanding the customs). Depending on programming language we use compilers and interpreters like gcc, python, perl, php, nodejs and sbcl. In Linux, OS X or BSD this all come very naturally but sometimes we find ourself using a Windows computer:

  1. We just happen to have a second Windows computer that we want to use
  2. Company policy requires us to use Windows
  3. We want to be capable of working in Windows
  4. We want our project to work fine in Windows
  5. Perhaps you are a Windows developer/user who need/want to do unix-like development without getting a separate computer.

This article is for you!

The good news is that basically everything you wish to do can be done with free software (also on Windows). What is also good is that you have plenty of choices of good stable software to choose from.

The bad news is that finding just what is right for you and making it feel as simple and smooth as you are used to can be time consuming, difficult and frustrating.

Embracing Windows
To be productive in Windows you should (at least to some degree) embrace Windows. One approach is to do as the Windows developers. This would mean using cmd.exe (the old DOS-shell) or Powershell, and learn/embrace what comes with it. You would perhaps install only node/php/python native for Windows and git. I encourage you to try this, but I will not write more about it.

This might be the best solution if you develop in JavaScript or Java AND basically all tools you use are part of a JavaScript/Java ecosystem. Perhaps git is the only thing you need apart from what you install with npm.

Avoiding Windows
One approach is to just use Windows to access (and possibly run a virtual) Linux (system). It can work better or worse depending on your situation. A full screen VM might be the best solution if Linux GUI tools are central to your development, or if you are anyway very used to working with VMs. SSH to a remote system might be the best solution if mobility is not a problem. However, some development gets more complicated when different things are on different IP addresses, and security becomes more relevant when everything is not on I will not write more about this.

Make Windows Unix-like
So, our gool is to feel reasonably at home in Windows by installing what is missing. It is always tricky to divide things in clear categories, but I would say you will want a stack of four layers:

  1. A Terminal Emulator: Windows already comes with one, but chances are you will not find it good enough. I have very modest demands but I expect copy-paste to work nicely and I expect multiple tabs. This works perfectly in any default Linux desktop and Mac OS X, not so in Windows.
  2. Editor: Unless you prefer to use vim or emacs directly in the terminal you want to install a decent or familiar text editor (Nodepad or Wordpad are not suitable for serious programming).
  3. The standard UNIX/GNU tools: Windows does not come with bash, head, tail, grep, sed, vim, bc and most other tools you take for granted. The old (DOS) equivalents are simply inferior. The new (Powershell) equivalents are… well… lets just say it is a steep learning curve and your bash scripts will not run.
  4. Interpreter/Compiler: Windows does not come with gcc, python, perl, nodejs or php. However, they are most often available as a separate download for Windows. Such a native Windows version may be slightly different from the Unix-version you are used too (command line options, especially related to paths may be different).

The short version is that you can install things like Cygwin or Windows Subsystem for Linux and you might just be fine with it! Or not. If you are bored of reading, try it out now.

To make a more informed choice you need to consider what types of binaries you want to run (and perhaps produce).

Native Windows Binaries
A Native Windows binary can (with some luck) be copied from a Windows computer to another and run. To interact with Windows (and you) it uses the APIs of Windows (typically Win32). It probably expects paths to be formed like in Windows (c:\tmp rather than /tmp).

Native Linux Binaries
A Native Linux binary was typically built on a Linux system to run on that Linux system (like Debian). Until recently it would not run on Windows, however Microsoft put a massive effort into Windows Subsystem for Linux, which allows you to run Linux programs (including bash) directly in Windows 10 (only). This is not perfect though. A Linux filesystem is quite different from a Windows filesystem so access between the two filesystems is limited and may require some thinking. This is perhaps the best approach if you are targetting Linux (like development for Docker) but it is obviously a bad approach if you want your program to work on a Windows server or other Windows computers.

Hybrid / Cygwin
There is an old (as in proven and reliable) project called Cygwin. It is basically a DLL-file that translates all (most) Linux system calls into Native Windows calls. This means that the unmodified source code of (most) programs written for Unix can be compiled with Cygwin, for Cygwin, and run on a Windows computer that has the Cygwin DLL installed. There are some drawbacks. First, performance suffers (from nothing to quite much depending on what you do). Second, for more advanced software, especially with GUI or heavy on network (like Apache), the hybrid solution can feel like the worst of two worlds. Third, access to the entire filesystem is smooth, but when it comes to access rights it sometimes does not work perfectly (files created by Cygwin get weird, even broken, permissions).

Now, to complicate things, there is a project called MSYS2 that maintains a fork of Cygwin, very similar to Cygwin. Cygwin or MSYS2 can be included/embedded in other projects (such as cmder). If you install multiple unix-compability-suites on your system it can get confusing.

Choosing binary type
At first glance Windows Subsystem for Linux, or Cygwin, seem very attractive. But lets assume that we do web development in Python. If you go with Windows Subsystem for Linux you will need to run a webserver (apache, lighttpd) inside that subsystem. To me, configuring, starting and stopping services inside this subsystem is not attractive. What could possibly go wrong? Well, a lot of things. With Cygwin you can probably make Windows IIS invoke Cygwin Python (if you really dont care about performance), because running Cygwin Apache sounds creepy (it can be done though). If, on the other hand you install Python built for Windows you get the real thing. All Windows/Python documentation and forum information suddenly applies to you. But then you end up with a Cygwin shell where everything is just like in Linux, except Python is not (except Cygwin will come with Python too, so you can end up with two versions of Python, with different features).

I would hesitate to run apache inside Cygwin and even more so inside Windows Subsystem for Linux. But I always also hesitate to do anything with IIS. Perhaps the best thing is to install Apache and Python for Windows (not depending on Cygwin) and just find the tools you need to edit your files?

The same reasoning can apply to PHP, nodejs or whatever you do.

Most configurations can probably be made to work. But you just want your Windows computer as simple and standard as possible, and you want your usual Linux (or OS X or BSD) stuff just to work the way they usually do. This is really not a matter of right or wrong, it is more a matter of taste (what kind of worthless errors do you want to solve just because you are a foreigner in Windows doing stuff not the way it was really meant to be done in Windows?).

Maintainability and Management
One thing is to make it work. Another thing is that it works week after week, month after month. Also another thing is to keep your software up to date and being able to add new tools along the way. You will find that some of the software I mention in this post does not come with the Windows installer/uninstaller that you are used to.

There is something called Chocolatey for Windows, which is a package manager dealing with installing, upgrading and uninstalling software on Windows in a uniform way. I don’t know much about it, and I will not write more about it.

While unix programs typically have a .file with configuration (there are a few places to look though) Windows programs typically use the registry. When it comes to unix software adapted for Windows you never really know: registry, config file, both or… depends on? And if a config file, where is it?

While unix programs can usually be installed in the home directory of an unpriviliged user, or in /opt, programs in Windows often require administrative priviliges to spread their files a little bit everywhere.

The more stuff you try and throw out, the more garbage you have left on your computer, which could possibly interfere with a newer version of something you install in the future. Keep this in mind. One day you will install some exotic software that does not work as expected, and you dont know if some old garbage on your computer caused it.

Git is a very popular version control system. Originally designed for Linux it is today (?) the officially preferred system also for native Windows development. Git is so popular (or demanding?) that you can get it bundled for Windows together with some of your favourite tools. This might be just enough for you!

  • posh-git : git for powershell
  • git for Windows : based on Git for Windows SDK
  • cmder : based on MSYS2
  • …more?

I have tried cmder and I dont like it. It is an ugly install of just unpacking a huge zip file. MSYS2 itself is hidden inside the cmder-folder, so I dont feel comfortable managing it on my own. There seems to be no upgrade strategy (except throwing it all away and downloading the latest version). Git is run from one shell (a traditional Windows shell with a lambda prompt) but a msys2/bash (identical to Cygwin) shell is started separately. I dont want to change console to run git: I run git all the time. But it might be perfect for you (many people like cmder).

Cygwin is nice becuase it comes with an installer (setup.exe) that is also a package manager. It has a lot of packages, and it is capable of installing things like apache as windows services. My experience is that I am too lazy downloading the latest setup.exe, and I am too lazy running setup.exe regularly. Sometimes you end up with old versions and upgrade problems.

My disappointment with Cygwin is that it comes with its own (compared to standard Windows) terminal Mintty that still does not have tabs. I also do nodejs development and nodejs is not a Cygwin package, so I need to use standard Windows node. This sucks a little because node in Windows behaves slightly different from node in Linux/OS X (particularly when it comes to where packages go) so the Cygwin experience is a bit broken when you start using Windows node and (perhaps particularly) npm.

Also, I like bash scripts and they tend to run significantly slower in Cygwin than in Linux (process forking is extremely cheap in Linux and rather expensive in Windows, so with the Cygwin overhead it can get rather slow for heavy scripts).

As I now try to update and configure my Cygwin environment for my Node.js project I find:

  • I use Cygwin wget to download setup.exe (so I get it where I want it, rather than Downloads) to update Cygwin. When I double click it (to run it) permissions are wrong and I cant execute it. It is an easy fix, but compared to OS X / Linux this is awkward.
  • I run node from Cygwin. I get no prompt (>). It turns out node.exe does not recognize Cygwin/bash as a terminal and I need to run node.exe -i.
  • Symlinks keep being a mystery. There are some kind of symlinks in Windows now, Cygwin seems to try to use them, but the result is not consistent.

For a Terminal with tabs, check Fatty below.

While the idea of Cygwin is to provide a Posix compliant environment on Windows the MinGW/MSYS project was about porting unix tools (perhaps particularly a gcc-based C/C++ build environment) to run natively on Windows. According to the Wikipedia page of MinGW this is pretty much abandoned.

Gow: GNU on Windows
Gnu on Windows is a lightweight alternative to Cygwin. It appears to not have been updated since early 2014 (when 0.8.0) came out (and the Windows Subsystem for Linux seems to be one reason it is less relevant). I will not write more about it.

MSYS2 is the successor to MSYS, and (surprise) it is based on Cygwin. I tried it quickly and I find that:

  • It seems safe to install side by side with Cygwin
  • Using the MSYS2 is very similar to Cygwin
  • Instead of the Cygwin GUI package installer, MSYS uses pacman from Arch (if you much prefer that, go with MSYS2)
  • MSYS2 has some emphasis on MinGW32 and MinGW64. As I understand it this is about being able to use MSYS2 to build native Windows software from C/C++ code (if you do this in Cygwin, you end up with a Cygwin dll dependency)

So, for my purposes MSYS2 seems to be quite equivalent to Cygwin. Expect the same annoyances as I mentioned for Cygwin above.

Windows Subsystem for Linux
If you try to run bash from a Windows 10 command line you will probably get something like:

-- Beta feature --
This will install Ubuntu on Windows, distributed by Canonical
and licensed under its terms available here:
In order to use this feature you must have Developer Mode enabled.
Press any key to continue...

Note that this can be quite confusing if you have installed some other bash.exe on your system. If you unexpectedly get the above message, check your PATH and make sure you invoke the right bash executable.

Installation is very easy (activate Developer mode and run bash), after giving username+password you are actually good to go! If you are used to Debian/Ubuntu you will feel surpisingly at home.

I find my Windows files in /mnt/c (not too surprising).
I find my Linux home files in c:\Users\zo0ok\AppData\Local\lxss\home\zo0ok.
(copying files there from Windows did not make them appear in Linux though)

So, if you want to edit files using a Windows GUI editor, they need to be in Windows-land, and that is obviously not the optimal environment for you project.

In general it works very well though. My node services had no problems listening to localhost:8080 and accepting incoming http requests from a Windows web browser.

If you are not happy with Ubuntu or you want more control of your Linux environment you will need to do further research. Ideally, Windows Subsystem for Linux has most of the advantages of a virtual machine, but none of the drawbacks. However, depending on what you really do and need, it can turn out to have most of the drawbacks and few of the advantages instead.

The Mintty terminal that comes with Cygwin is ok, but it does not support tabs. There are different alternatives, and a simple one is Fatty (it is really Mintty with tabs). Installing Fatty requires doing a git clone and compiling it yourself. If you are brave you can download fatty-1.6.exe from me.

The web page for fatty tells you how to make a desktop shortcut but it did not work for me. What works for me is to set Shortcut target: “C:\cygwin64\bin\fatty.exe -“. Simple as that. I think I will be quite fine with fatty, actually.

Making Fatty run Windows Subsystem for Linux was trickier (as in no success) though.

ConEmu seems to be the ultra powerful flexible console. After 5 minutes I have still not found out how to change the font size.

ConsoleZ is good. Under Edit->Settings>Tabs you can add your own shell types.

Cygwin:                       Shell = C:\cygwin64\bin\bash.exe --login
Windows Subsystem for Linux:  Shell = bash.exe

Apart from that, ConzoleZ is reasonably easy to configure and it stays out of your way (I hide toolbar, status bar, search bar).

I am fine with vim in the console. However, there are many fine editors for Windows:

  • Visual Studio Code (at no cost)
  • Atom
  • Notepad++

I have had Windows as a 2nd/3rd platform for many years and I can see that the game has changed a bit. Microsoft has started supporting Ubuntu on Windows and at the same time the native options (like MSYS) are fading away. There are reasons to think general development is getting more and more based on Unix.

I would say:

  • Posh-git : Powershell is your thing, and you don’t care about unix tools
  • Git for Windows : You want Git, but you don’t care much about other unix tools
  • Cygwin : You want plenty of choices of unix tools in Windows
  • MSYS2 : You like pacman (Arch) or you want to build native Windows C/C++ binaries using free software
  • Windows Subsystem for Linux : You have a Windows 10 computer but you want to keep your Linux development separate from Windows

If you use Cygwin and just want tabs, get Fatty. Otherwise ConsoleZ is good. Chocolatey is more a Windows power user tool than something you need to provide unix capabilities.

In the past I have mostly been using Cygwin (with mixed feelings). Lately, when I have heard about the options (cmder, poshgit, Git for Windows, MSYS2) I have got a feeling that it is rather hard to configure an optimal environment. Now however I have come to realize that the differences are not very big. Most options are hybrids based on Cygwin and/or with Cygwin embedded (perhaps in the name of MSYS2). For Windows developers not used to Unix it is good with things like Git for Windows that just come with the basic Unix tools with no need to think about it. For developers with a Unix background it makes more sense to run Cygwin and MSYS2 (or Windows Subsystem for Linux). The days of unix tools built natively for Windows are over, and it is probably a good thing.

What you need to think about is your compiler, interpreter and/or web server.