Quoting an example from [`git-filter-branch(1)`][1]

&gt; To rewrite the repository to look as if foodir/ has been its project root, and discard all other history:

    git filter-branch --subdirectory-filter foodir -- --all

&gt; Thus you can, e.g., turn a library subdirectory into a repository of its own.  Note the -- that separates filter-branch options from revision options, and the --all to rewrite all branches and tags.

[1]: https://www.kernel.org/pub/software/scm/git/docs/git-filter-branch.html

For anyone else arriving here in 2021 (or later), git filter-branch is not strongly recommended by the core git team. 

&gt; WARNING
git filter-branch has a plethora of pitfalls that can produce non-obvious manglings of the intended history rewrite (and can leave you with little time to investigate such problems since it has such abysmal performance). These safety and performance issues cannot be backward compatibly fixed and as such, its use is not recommended. Please use an alternative history filtering tool such as git filter-repo. If you still need to use git filter-branch, please carefully read SAFETY (and PERFORMANCE) to learn about the land mines of filter-branch, and then vigilantly avoid as many of the hazards listed there as reasonably possible.

Instead the recommended tool is [git-filter-repo][1] which makes easy work of this problem

```bash
git filter-repo --path subfolder/   # Filter the repo to just the sub-dir
git mv subfolder/* .                # Move the contents of the sub-dir to the root
git commit -m &quot;Filtered from main repo&quot;
```


  [1]: https://github.com/newren/git-filter-repo

I want to append a `&lt;br /&gt;` to a particular class. Using the :after pseudo class simply displays `&lt;br /&gt;` as text.

Is there a way to make this work?

It&#39;s internal for IE8 so browser issues aren&#39;t a problem. If I do

    &lt;span class=&quot;linebreakclass&quot;&gt;cats are&lt;/span&gt; brilliant

I want &quot;brilliant&quot; to appear on a new line.

Can you add line breaks to the :after pseudo element?

How can I (if it is possible at all) initialize multiple variables of different type in a C# `for` loop? Example:

    for (MyClass i = 0, int j = 1; j&lt;3; j++,i++)


Multiple initialization in C# &#39;for&#39; loop

I have a folder in my Git repository that I&#39;d like to move out in to its own repository. Is it possible to move the history of that folder along with the folder?

I&#39;ve previously been doing just a `git rm -r --cached subfolder/` and then `git init` on the subfolder. However, the history is not imported in to the new repository.

Export subtree in Git with history

<p>I have a folder in my Git repository that I'd like to move out in to its own repository. Is it possible to move the history of that folder along with the folder?</p>
<p>I've previously been doing just a <code>git rm -r --cached subfolder/</code> and then <code>git init</code> on the subfolder. However, the history is not imported in to the new repository.</p>


I have two branches. Commit `a` is the head of one, while the other has `b`, `c`, `d`, `e` and `f` on top of `a`. I want to move `c`, `d`, `e` and `f` to first branch without commit `b`. Using cherry pick it is easy: checkout first branch cherry-pick one by one `c` to `f` and rebase second branch onto first. But is there any way to cherry-pick all `c`-`f` in one command?

Here is a visual description of the scenario (thanks [JJD](/users/356895/JJD)):

![enter image description here](http://i.stack.imgur.com/7k9Ev.png)

How to cherry-pick multiple commits

I am a new user to `git` and I am starting a new project. I have a bunch of dot files that I would like to ignore. Is there an ignore command for `git` like there is for `svn`?

Is there an ignore command for git like there is for svn?

I have a Git repository in a folder called **XXX**, and I have second Git repository called **YYY**.

I want to import the **XXX** repository into the **YYY** repository as a subdirectory named **ZZZ** and add all **XXX**&#39;s change history to **YYY**.

Folder structure before:

```
├── XXX
│   ├── .git
│   └── (project files)
└── YYY
    ├── .git
    └── (project files)
```

Folder structure after:

```
YYY
├── .git  &lt;-- This now contains the change history from XXX
├──  ZZZ  &lt;-- This was originally XXX
│    └── (project files)
└──  (project files)
```

Can this be done, or must I resort to using sub-modules?


How to import existing Git repository into another?

Is it somehow possible to **automatically** have a link to GitHub issue number in the `git commit` message?

Link to the issue number on GitHub within a commit message

I am new to Git and I seem to have one branch too many if I execute the following command:

    warning: refname &#39;HEAD&#39; is ambiguous.

I get the following output:

    warning: refname &#39;HEAD&#39; is ambiguous.
    From github.com:dagda1/hornget
     * branch            master     -&gt; FETCH_HEAD
    warning: refname &#39;HEAD&#39; is ambiguous.
    warning: refname &#39;HEAD&#39; is ambiguous.

If I execute `git branch -a`

I get the following:

    HEAD
    * master
    remotes/emmekappa/master
    remotes/origin/HEAD -&gt; origin/master
    remotes/origin/master

I am confused by the `remotes/origin/HEAD -&gt; origin/master`.

What is this and how can I get rid of the ambiguous branch.

I got to this stage by performing a merge where I think I added the ambiguous branch.


warning: refname &#39;HEAD&#39; is ambiguous

I have very large tables (30 million rows) that I would like to load as a dataframes in R.  `read.table()` has a lot of convenient features, but it seems like there is a lot of logic in the implementation that would slow things down.  In my case, I am assuming I know the types of the columns ahead of time, the table does not contain any column headers or row names, and does not have any pathological characters that I have to worry about.

I know that reading in a table as a list using `scan()` can be quite fast, e.g.:

    datalist &lt;- scan(&#39;myfile&#39;,sep=&#39;\t&#39;,list(url=&#39;&#39;,popularity=0,mintime=0,maxtime=0)))

But some of my attempts to convert this to a dataframe appear to decrease the performance of the above by a factor of 6:

    df &lt;- as.data.frame(scan(&#39;myfile&#39;,sep=&#39;\t&#39;,list(url=&#39;&#39;,popularity=0,mintime=0,maxtime=0))))



Is there a better way of doing this?  Or quite possibly completely different approach to the problem?


Quickly reading very large tables as dataframes

I am using django and I have a file named models.admin.py and I want to do the following idea in models.py:

    from &quot;models.admin&quot; import *

however, I get a syntax error for having double quotes. But if I just do 

    from models.admin import *

then I get &quot;ImportError: No module named admin&quot;

Is there any way to import from a python file that has a period in its name?

How to reference python package when filename contains a period

In Java, if you import a deprecated class:

    import SomeDeprecatedClass;

You get this warning: `The type SomeDeprecatedClass is deprecated`

Is there a way to suppress this warning?

Suppress deprecated import warning in Java

I am running an import that will have 1000&#39;s of records on each run.  Just looking for some confirmation on my assumptions:

Which of these makes the most sense:

 1. Run `SaveChanges()` every `AddToClassName()` call.
 2. Run `SaveChanges()` every *n* number of `AddToClassName()` calls.
 3. Run `SaveChanges()` after *all* of the `AddToClassName()` calls.

The first option is probably slow right?  Since it will need to analyze the EF objects in memory, generate SQL, etc.

I assume that the second option is the best of both worlds, since we can wrap a try catch around that `SaveChanges()` call, and only lose *n* number of records at a time, if one of them fails.  Maybe store each batch in an List&lt;&gt;.  If the `SaveChanges()` call succeeds, get rid of the list.  If it fails, log the items.

The last option would probably end up being very slow as well, since every single EF object would have to be in memory until `SaveChanges()` is called.  And if the save failed nothing would be committed, right?

When should I call SaveChanges() when creating 1000&#39;s of Entity Framework objects? (like during an import)


Is it possible to import a class in Java which is in the default package?  If so, what is the syntax?  For example, if you have

    package foo.bar;

    public class SomeClass {
        // ...

in one file, you can write

    package baz.fonz;

    import foo.bar.SomeClass;

    public class AnotherClass {
        SomeClass sc = new SomeClass();
        // ...

in another file.  But what if SomeClass.java does not contain a package declaration?  How would you refer to &lt;code&gt;SomeClass&lt;/code&gt; in &lt;code&gt;AnotherClass&lt;/code&gt;?


  [1]: https://stackoverflow.com/questions/283816/how-to-access-java-classes-in-the-default-package

What&#39;s the syntax to import a class in a default package in Java?

Please tell me how to export a function in parent shell (bash, sh or ksh) so that the function will be available to all the child process launced from the parent process?

Exporting a function in shell

I&#39;m trying to create a simple structure only dump of my database. Using `mysqldump` gives me a result like:

    /*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
    /*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
    /*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE=&#39;NO_AUTO_VALUE_ON_ZERO&#39; */;
    /*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

    DROP TABLE IF EXISTS `foo`;
    /*!40101 SET @saved_cs_client     = @@character_set_client */;
    /*!40101 SET character_set_client = utf8 */;

No matter what I try, I just can&#39;t seem to get rid of those comments.

I&#39;m currently using: `mysqldump -p -d --add-drop-table --skip-tz-utc --skip-set-charset -h 127.0.0.1 -u foo bar --result-file=dumpfile.sql`

**Edit:** I do however wish to retain other comments, such as `-- MySQL dump 10.13  Distrib 5.1.41, for Win32 (ia32)`

How can I get rid of these comments in a MySQL dump?

I&#39;m looking for a way to do something analogous to the MySQL dump from SQL Server. I need to be able to pick the tables and export the schema and the data (or I can export the schema via SQL Server Management Studio and export the data separately somehow).

I need this data to be able to turn around and go back into SQL Server so it needs to maintain GUIDs/uniqueidentifiers and other column types.

Does anyone know of a good tool for this?

How to get script of SQL Server data?

I&#39;m looking for a class for creating CSV Excel files.

Expected features:

* Extremely simple to use
* Escapes commas and quotes so excel handles them fine
* Exports date and datetimes in timezone-proof format

Do you know any class capable of this?

How to create CSV Excel file C#?

I have some CSV data and I want to import into django models using the example CSV data:

    1;&quot;02-01-101101&quot;;&quot;Worm Gear HRF 50&quot;;&quot;Ratio 1 : 10&quot;;&quot;input shaft, output shaft, direction A, color dark green&quot;;
    2;&quot;02-01-101102&quot;;&quot;Worm Gear HRF 50&quot;;&quot;Ratio 1 : 20&quot;;&quot;input shaft, output shaft, direction A, color dark green&quot;;
    3;&quot;02-01-101103&quot;;&quot;Worm Gear HRF 50&quot;;&quot;Ratio 1 : 30&quot;;&quot;input shaft, output shaft, direction A, color dark green&quot;;
    4;&quot;02-01-101104&quot;;&quot;Worm Gear HRF 50&quot;;&quot;Ratio 1 : 40&quot;;&quot;input shaft, output shaft, direction A, color dark green&quot;;
    5;&quot;02-01-101105&quot;;&quot;Worm Gear HRF 50&quot;;&quot;Ratio 1 : 50&quot;;&quot;input shaft, output shaft, direction A, color dark green&quot;;


I have some django models named Product. In Product there are some fields like `name`, `description` and `price`. I want something like this:

    product=Product()
    product.name = &quot;Worm Gear HRF 70(02-01-101116)&quot;
    product.description = &quot;input shaft, output shaft, direction A, color dark green&quot;
    product.price = 100

how to import csv data into django models

I am a C and C++ programmer and am now trying to learn C#. I have bought the book [Professional C#][1] by Wrox publications. 

While migrating from C to C++ I had a doubt why `++` was added to C. Later on I realized that since `++` is an increment operator and it was added to C just to provide an &#39;Object Oriented Extension&#39;.

In C#, what is the significance of `#`?



  [1]: http://www.amazon.com/Professional-2008-Wrox-Guides/dp/0470191376

Origin of the C# language name

I know that in the architectures I&#39;m personally familiar with (x86, 6502, etc), the stack typically grows downwards (i.e. every item pushed onto the stack results in a decremented SP, not an incremented one). 

I&#39;m wondering about the historical rationale for this. I know that in a unified address space, it&#39;s convenient to start the stack on the opposite end of the data segment (say) so there&#39;s only a problem if the two sides collide in the middle. But why does the stack traditionally get the top part? Especially given how this is the opposite of the &quot;conceptual&quot; model?

(And note that in the 6502 architecture, the stack also grows downwards, even though it is bounded to a single 256-byte page, and this direction choice seems arbitrary.)

Why do stacks typically grow downwards?

Many of you have seen [this graph][1] of Google Trends of popular AJAX frameworks (Dojo, jQuery, YUI).

The graph seems to make it clear that interest in Dojo collapsed in the second quarter of 2008, falling by 80%; jQuery picked up the slack and ultimately grew to more than triple the size of Dojo.

Why?  What happened in Q2 2008 that demolished interest in Dojo?

(Note that I&#39;m not really interested in a comparison of [Dojo vs. jQuery][2]; even if you can explain why one is better than the other, it&#39;s hard to see why that suddenly became clear to the world in April 2008.)


  [1]: http://www.google.com/trends?q=jquery%2Cdojo%2Cyui &quot;Google Trends: jquery,dojo,yui&quot;
  [2]: https://stackoverflow.com/questions/394601/which-javascript-framework-jquery-vs-dojo-vs &quot;Which Javascript framework (jQuery vs Dojo vs … )?&quot;

What happened to Dojo in 2008?

Using [Chris&#39;s answer](https://stackoverflow.com/questions/3147097/how-to-prepend-the-past-to-a-git-repository/3148117#3148117) on another question I could prepend a snapshot-history to my git repository. Since one of the files is not part of my history but only in the snapshots, the first original commit now also contains the deletion of this file. How can I undo that?

*At first I thought this was the opposite of [How do I remove sensitive files from git’s history](https://stackoverflow.com/questions/872565/how-do-i-remove-sensitive-files-from-gits-history), but actually I don&#39;t want to insert a file into history but just remove the deletion from history.*

How to undelete a file previously deleted in git&#39;s history?

Is there a way to get the SQL text for the last few queries?

I am using Microsoft SQL Server 2005

Content Type	Original Author	Original Content on Stackoverflow
Question	matpie	View Question on Stackoverflow
Solution 1 - Git	jamessan	View Answer on Stackoverflow
Solution 2 - Git	Jamie Cook	View Answer on Stackoverflow

Export subtree in Git with history

Git Problem Overview

Git Solutions

Solution 1 - Git

Solution 2 - Git

Multiple initialization in C# 'for' loop

Can you add line breaks to the :after pseudo element?

Attributions