Git line endings revisited and .gitignore

Git-scm.com revised their line ending fix-up instructions in a way that seems to remove ignored files from the repository.

Here are the new instructions:

echo "* text=auto" >.gitattributes
git read-tree --empty   # Clean index, force re-scan of working directory
git add .
git status              # Show files that will be normalized
git commit -m "Introduce end-of-line normalization"

.NET IsAssignableFrom

For some reason I have a mental block remembering which way .NET's IsAssignableFrom() function works, so, using the excellent LINQPad and the following code snippet, I came up with the following results:

typeof(BaseClass).IsAssignableFrom(typeof(DerivedClass)) // true

typeof(DerivedClass).IsAssignableFrom(typeof(BaseClass)) // false

Code:

void Main()
{
 typeof(BaseClass).IsAssignableFrom(typeof(DerivedClass)).Dump("typeof(BaseClass).IsAssignableFrom(typeof(DerivedClass))");
 typeof(DerivedClass).IsAssignableFrom(typeof(BaseClass)).Dump("typeof(DerivedClass).IsAssignableFrom(typeof(BaseClass))");
}
    
class BaseClass { }
class DerivedClass : BaseClass { }

C# 6 String Interpolation Does Not Concatenate

Well, I learned something new today that's slightly disappointing. I had thought that C# 6 string interpolation concatenated strings or perhaps used the StringBuilder or some such under the hood. It turns out it merely creates a good, old-fashioned String.Format statement out of it.

Given this source code:

The resulting IL (compiled) code is the following (obtained using LINQPad):

Note the following two statements:

ldstr       "A{0}C"
call        System.String.Format

These indicate that String.Format is being called with the familiar-looking format string "A{0}C".


To compile the C# code and create IL code, I used Joe Albahari's excellent LINQPad program.

WebClient vs HttpClient vs HttpWebRequest

All the clients explained.

http://www.diogonunes.com/blog/webclient-vs-httpclient-vs-httpwebrequest/

To quote from the link:

• HttpWebRequest for control
• WebClient for simplicity and brevity
• RestSharp for both on non-.NET 4.5 environments
• HttpClient for both + async features on .NET 4.5 environments

Shallow Copy an array in JavaScript

Who knew?

var copyOfArray = originalArray.slice();

Apparently Array.slice, if called with no parameters, returns a copy of the entire array. Kinda cool!

Formatting in ReSharper vs. formatting in Visual Studio

Interesting. Ctrl-K Ctrl-D reformats a file using Visual Studio rules, while Ctrl-Alt-Enter reformats a file using ReSharper rules.

Here's an example, using Visual Studio formatting (Ctrl-K Ctrl-D):

            var patient = new Patient { AccountNumber = accountNumber };

And the same code using ReSharper formatting (Ctrl-K Ctrl-F):

            var patient = new Patient {AccountNumber = accountNumber};

I would have thought that ReSharper would take over the Ctrl-K Ctrl-D and Ctrl-K Ctrl-F keyboard shortcuts, but it does not.

Testing fonts for ambiguity

This is the string used by Visual Studio's font configuration that indicates whether a font is ambiguous or not for developers:

Setting Environment variables in ASP.NET Core

From http://stackoverflow.com/questions/31049152/publish-to-iis-setting-environment-variable/36836533#36836533:

"Turns out environment variables for ASP.NET Core projects can be set without having to set environment variables for user or having to create multiple commands entries....

"This way you do not have to create special users for your pool or create extra commands entries in project.json. Also, adding special commands for each environment breaks build once, deploy many times' as you will have to call dnu publish separately for each environment, instead of publish once and deploying resulting artifact many times."

Git lg -- a better Git log

From https://coderwall.com/p/euwpig/a-better-git-log:

Git add non-whitespace changes revisited

There's a better version of what I blogged about here.

Source: http://stackoverflow.com/questions/3515597/add-only-non-whitespace-changes#comment61915463_7149602

Visual Studio's most useful (and underused) tips

I discovered Map Mode for the scrollbar. I have seen people use that but always thought it was from a Visual Studio plugin.

Also, who knew you could compare files with Visual Studio?

Navigate to -- Ctrl+, -- is another discovery, as well as moving lines up and down with Alt-Up and Alt-Down.

Visual Studio's most useful (and underused) tips

GitTfs commands I use every day, round 2

I modified my TfsFetch.sh script to display the name of the current branch. This is to aid in situations where feature branches are being used.

Here's the current script:

Normalize line endings before removing ignored files

When using the scripts I have blogged about for normalizing line endings and removing ignored files, run the script to normalize line endings first before removing ignored files.

The old 'TFS Repository can not be root and must start with "$/"' error

When using git-tfs to clone a repository using the bash shell, this error is common:

$ git tfs clone https://tfsserver/tfs/DefaultProjectCollection/ "$/path/to/tfs/project"
TFS repository can not be root and must start with "$/".
You may be able to resolve this problem.

The solution? Prepend MSYS_NO_PATHCONV=1 to the command, e.g.:

$ MSYS_NO_PATHCONV=1 git tfs clone https://tfsserver/tfs/DefaultProjectCollection/ "$/path/to/tfs/project"
Initialized empty Git repository in C:/Projects/path/to/tfs/project/.git/
Fetching from TFS remote 'default'...
C6782 = 81584efc08348f7dc4c81297e4e82115789a1e3d
C6784 = 6a6a8bd55111286b24c7acd4825e4ef79030d693
C6863 = 60e8369f34b16a6123d7ed22bf60e59db46ee2e9
etc.

TestDisk - Partition Recovery and File Undelete

I wish I'd known about this a few months ago. I accidentally make a disk unbootable, but eventually, after many hours of struggle, I got it working again. This might have save me those many hours.

TestDisk - Partition Recovery and File Undelete

I found this reading the original Server Fault post on the huge data loss allegedly suffered by someone at a British web hosting company.

Linux command line mistake nukes web boss' biz • The Register

centos7 - Recovering from a rm -rf / - Server Fault

Cleaning Visual Studio solutions when using Git

Visual Studio has a "Clean Solution" command, of course, but it's conservative in what it cleans and sometimes leaves detritus around that most of the time you want eliminated. It seems to only clean files -- DLL's and PDB's, mostly, but also content configured to be copied to the output folder -- that are created by the current source code and copied references and other files. It also does not eliminate files created at runtime -- for instance error logs -- that your program may have created. One situation in which files are not deleted by the "Clean Solution" or the "Clean Project" command is when you remove an assembly or project reference from a project before you clean it. The removed reference remains in your project's output directory.

Let Git come to the rescue! Assuming that you have a sensible .gitignore file, the following command will delete all bin and obj folders from your project and all subprojects:

Deleting git index file, a.k.a. more authoritative methods of dealing with Git line ending problems

The classic problem in Windows with line endings in files repeatedly rears its ugly head. I've tried a number of different ways over the years of dealing with them, but I discovered today that the gitattributes documentation actually gives a recipe for dealing with it, which I'll reproduce here:

$ echo "* text=auto" >>.gitattributes
$ rm .git/index     # Remove the index to force Git to
$ git reset         # re-scan the working directory
$ git status        # Show files that will be normalized
$ git add -u
$ git add .gitattributes
$ git commit -m "Introduce end-of-line normalization"

Source: http://git-scm.com/docs/gitattributes#_end_of_line_conversion

Meanwhile, the people over at Github have a slightly different approach. (I'm wondering if rm .git/index followed by git reset is the same as git rm --cached -r.) [EDIT: I realize upon studying this that this version will touch all files in the source tree, whereas the version above does not.]

$ echo "* text=auto" >>.gitattributes
$ git rm --cached -r .
$ git reset --hard
$ git add .
$ git commit -m "Normalize all the line endings"

Source: Refreshing a repository after changing line endings (Github)

The potential problem of the Github approach is that it would add files you might not want in your repository if your repository has any extra stuff in it, i.e. if doing a git status before their procedure shows any files not in the repository.

What's very interesting about the Github approach is that it's very similar to my method for removing all files from a repository that you'd actually like to ignore, except that my steps are missing the git reset --hard command:

$ git rm --cached -r .
$ git add .gitignore
$ git add .
$ git commit -m "Remove ignored files."




git reset vs git reset --hard

One thing I'm not sure of is the difference between git reset and git reset --hard in the Github approach. I'll have to think about that another time. :)

Five advanced Git merge techniques

Some very interesting stuff here.

I knew about (but forgot) #1 -- including "base" in the merge file output -- but some of the other things are pretty interesting as well.

#4 -- git merge-file, which redoes the merge -- looks particularly interesting and powerful and helps out in the classic newlines style situations I often find myself in.

http://blog.ezyang.com/2010/01/advanced-git-merge/

This blog, subtitled "Existential Pontification and Generalized Abstract Digressions," and which I only recently discovered, seems primarily concerned with Haskell but has a huge helping of computer science articles as well. The name of the blog -- "Inside 736-131" -- sounds like the name of a computer science course at MIT. [Edit: now I see that it's apparently Stanford-specific.]

Keeping RDP sessions from locking due to inactivity

YMMV.

Create a VBS file with the following contents:

Do
 Set WSHShell = WScript.CreateObject("WScript.Shell")
 WSHShell.SendKeys ("{SCROLLLOCK}")
 Set WSHShell = Nothing
 WScript.Sleep (2*1000)
Loop 

Save as a VBS and run on whatever machine you want to stay open.


5/26/16 Edit: here's a better version that does not toggle the ScrollLock key and also increases the delay to minimize disruption:

Do
  Set WSHShell = WScript.CreateObject("WScript.Shell")
  WSHShell.SendKeys ("{SCROLLLOCK}{SCROLLLOCK}")
  Set WSHShell = Nothing
  WScript.Sleep (60*1000)
Loop

Git: removing cruft from a repository that was added without a .gitignore file

I inherited a Visual Studio project, originally in TFS, where the developer before me added files somewhat willy-nilly to the repository without any sort of filter. Thus, NuGet packages, the bin and obj directories, user settings, and even error logs were committed to version control.

Long story short, I scratched my head over how to clean up the repository such that ignored files were excluded from it. I started picking through by location, file type, and so on, but this took too long, was too tedious, and was likely to miss some files.

Finally, the solution hit me, and it's really quite simple. Here are the steps:

Step 1: remove the entire repository or folder.

$ git rm --cached -r .

Step 2 (optional): if it wasn't already present, add the .gitignore folder obtained from, e.g. the gitignore project:

$ git add .gitignore

Step 3: add back the folder

$ git add .

Step 4: commit the whole shebang:

$ git commit -m "Remove ignored files."

Voila! The resulting commit status (or diff) will show all undesired files being removed.


[5/26/16 Edit: here are all the lines of code together:
]