git


Git: Perform a stash addition using a custom/meaningful message

Did you ever wonder “Is there more to git stash?”, we did!
We wanted to see if there is a way to manually set the stash message to something meaningful instead of the automated message that derives from the last commit.

Fortunately, there is the command git stash save "Meaningful message"; which allows you to add new changes in your stash and at the same time use a custom message.

By using the git stash save "custom message"; command you will be enhancing the results of the git stash list; command as it will contain more useful information for you.

Example

$ git status;
On branch master
Changes not staged for commit:
 (use "git add <file>..." to update what will be committed)
 (use "git checkout -- <file>..." to discard changes in working directory)

modified: me

no changes added to commit (use "git add" and/or "git commit -a")
$ git stash save "custom message";
Saved working directory and index state On master: your message here
$ git stash list 
[email protected]{0}: On master: custom message
$ git stash show
 me | 1 +
 1 file changed, 1 insertion(+)

Find all git repositories and perform a pull operation on them.

The following command will find all git projects in your home folder and perform a pull operation on them.

find ~ -name ".git" -type d -exec bash -c "echo '{}' && cd '{}'/.. && git pull" \;

The above command is based on finding the .git folders that exist in any clone of a git repository. Once a .git folder is found, it will navigate to its parent folder where it will perform the pull request.

Bonus – Automate the procedure using a cron job

The following entry in crontab allows us to periodically perform a pull request on all the cloned repositories that we have in a specific folder. Specifically, it will perform this operation once every five minutes.

*/5    *    *    *    *    cd /home/bytefreaks/Projects; find . -name ".git" -type d -exec bash -c "echo '{}' && cd '{}'/.. && git pull" \; &> /tmp/bf.git.log

Please note that it would be easier to use an ssh key that does not have a password for this automation.
If you do not, the you will need to either pass the password via this configuration line (not recommended) or have a key agent running to provide the password for the key.

How to execute `find` that ignores .git directories

Trying to find a source code file by its content using find and -exec grep, can some times result in getting results from the repository .git folders as well.

This behavior not only does it provide results you do not need but it also makes your search slower.
Below, we propose a couple of solutions on how to make a more efficient search.

Example 1: Ignore all .git folders no matter where they are in the search path

For find to ignore all .git folders, even if they appear on the first level of directories or any in-between until the last one, add -not -path '*/\.git*' to your command as in the example below.
This parameter will instruct find to filter out any file that has anywhere in its path the folder .git. This is very helpful in case a project has dependencies in other projects (repositories) that are part of the internal structure.

find . -type f -not -path '*/\.git/*';

Note, if you are using svn use:

find . -type f -not -path '*/\.svn/*';

Example 2: Ignore all hidden files and folders

To ignore all hidden files and folders from your find results add -not -path '*/\.*' to your command.

find . -not -path '*/\.*';

This parameter instructs find to ignore any file that has anywhere in its path the string /. which is any hidden file or folder in the search path!


How to undo a Git commit that was not pushed 1

To undo a Git commit that was not pushed, you are given a few major options:

  1. Undo the commit but keep all changes staged
  2. Undo the commit and unstage the changes
  3. Undo the commit and lose all changes

Method 1: Undo commit and keep all files staged

In case you just want to undo the commit and change nothing more, you can use

git reset --soft HEAD~;

This is most often used to make a few changes to your latest commit and/or fix your commit message. Leaves working tree as it was before reset.
soft does not touch the index file or the working tree at all (but resets the head to the previous commit). This leaves all your changed files Changes to be committed, as git status would put it.

Method 2: Undo commit and unstage all files

In case you want to undo the last commit and unstage all the files you can use the following

git reset HEAD~;

or

git reset --mixed HEAD~;

mixed will reset the index but not the working tree (i.e., the changed files are preserved but not marked for commit) and reports what has not been updated. This is the default action.

Method 3: Undo the commit and completely remove all changes

The following method will undo the commit and revert all changes so that your state is exactly as it was before you started making changes.

git reset --hard HEAD~;

hard resets the index and working tree. Any changes to tracked files in the working tree since the previous commit are discarded.

 

Note: In case you just want to rewrite the commit message, you could use git –amend instead.


How does ‘git pull’ and ‘git fetch’ differ?

In simple terms, the difference between the two Git commands is that git pull is composed by a git fetch followed by a git merge.

When you use git pull, Git will automatically merge any pulled commits into the branch you are currently working in, without letting you review them first. You will get a prompt only if there is conflict found during automatic merging.

When you use git fetch, Git retrieves any commits from the target branch that do not exist in your current branch and stores them in your local repository. However, it will not merge them with your current branch. To integrate the new commits into your current branch, you need to use git merge manually.
This command is particularly useful if you need to keep your repository up to date, but are working on something that might break if you merge your files.
For example, if you will go offline and you need to have those commits available to you but cannot merge at the time, using git fetch you will download the new commits to your machine without affecting your current code. Later you will be able to merge the new commits to your branch as/when you please.


Just some notes for setting up a new OS to develop projects on GNU/Linux Fedora

If the project is in C++ and uses mysql then install

sudo dnf install mysql++-devel;

If the project is in C/C++ and you are missing talloc.h install

sudo dnf install libtalloc-devel;

Set your name and email for all git projects

git config --global --edit
Then fill-in the configuration file similar to below
# This is Git's per-user configuration file.
[user]
# Please adapt and uncomment the following lines:
#       name = Michael, George
#       email = [email protected]
[user]
        name = Michael, George
        email = [email protected]
[gui]
        editor = gedit

or use these individual commands to set the configuration

[[email protected] ~]$ git config --global user.name "Michael, George"
[[email protected] ~]$ git config --global user.email "[email protected]"

Increase amount of inotify watchers

If you are using CLion or IntelliJ IDEA by jetbrains increase the amount of inotify watchers.
CLion, IntelliJ (and other tools of jetbrains) use inotify on GNU/Linux to monitor directories for changes. It’s common to encounter the system limit on the number of files they monitor.

inotify requires a watch handle to be set for each directory in the project. Unfortunately, the default limit of watch handles will not be enough for sized projects, and reaching the limit will force the jetbrains platform to fall back to recursive scans of directory trees.

Create a file (as root) called /etc/sysctl.d/idea.conf and add the following content to it to increase the number of watchers to 512K

fs.inotify.max_user_watches = 524288

Then call sysctl to reload the settings and apply the new configuration

[[email protected] ~]$ sudo sysctl -p --system;
  •  -p[FILE] or --load[=FILE]: Load in sysctl settings from the file  specified  or /etc/sysctl.conf if none  given.
    Specifying - as filename means reading data from standard input. Using this option will mean arguments to sysctl are files, which are read in the order they are specified.
    The file argument may be specified as regular expression.
  •  --system: Load settings from all system configuration files.
     /run/sysctl.d/*.conf
     /etc/sysctl.d/*.conf
     /usr/local/lib/sysctl.d/*.conf
     /usr/lib/sysctl.d/*.conf
     /lib/sysctl.d/*.conf
     /etc/sysctl.conf

git: How to move locally committed (but not pushed) changes to a new branch

Recently, we’ve been working on a certain branch, we did some changes and performed a couple of commits that were not pushed on the remote system.

There was a complication and it was decided that the local changes should not be pushed to the branch that we were working on.
Rather, they changes should go to a new branch which eventually will be merged.

As mentioned above, we already had done some changes and we already had performed the commits.

git status would give us the following:

$ git status;
On branch scanner_pdu_parser_master
Your branch is ahead of 'origin/scanner_pdu_parser_master' by 2 commits.
  (use "git push" to publish your local commits)

So, we needed to change the branch for those local commits.

Solution – Move the local commits to a new branch

First we got the name of the current branch using the command:

git branch;

Then, we switched to a new local branch

git checkout -b banana_peeler;

And, we pushed the local branch to the remote system:

git push --set-upstream origin banana_peeler;

Afterwards, we switched back to the previous branch

git checkout apple_peeler;

And reset it back to its original form, removing our local commits from it:

git reset --hard origin/apple_peeler;

Please note that the last command will delete all changes that are not committed as well.
In other words, any file you modified and did not commit or push, they will be reverted back to the original code as well.