4 minutes
Useful Commands
Since it is quite pain to search and copy-paste commands from Google / Duck all the time I’ll write some useful commands down in here.
This post will be updated from time to time, so everything is in one place
Git
Change remote URL
Good when remote has moved, renamed or just want to replace https with ssh
To see current remote URL:
Signature:
git remote set-url REMOTE_NAME REMOTE_PATH
Usage:
git remote set-url origin [email protected]:group/project/example-com.git
Change (current) branch base branch
Good in cases where you created new branch based on wrong branch.
For example wanted to create new branch based on master
but accidentally made it based on demo
and ended up with history like this:
(commit 1) -> master
\__ (commit 2) -> demo
\__ (commit 3) -> new_branch
But that’s the history you are after:
(commit 1) -> master
|__ (commit 2) -> (commit 3) -> demo
\__ (commit 4) -> (commit 5) -> new_branch
Use rebase –onto for that
Signature:
git rebase --onto newBase oldBase feature/branch
Usage for current example:
git rebase --onto master demo new_branch
Basically, you take all the commits from after
demo
up tonew_branch
, and rebase them onto themaster
commit.
Reset only file permission changes
Good to revert all file permission changes that have been accidentally done.
Most common use case is when sharing codebase between Windows and Linux. After editing files on Windows file permissions tend to be changed in Linux
Only works from project root
Git keeps track of file permission and exposes permission changes when creating patches using
git diff -p
.So all we need is:
- Create a reverse patch
- Include only the permission changes
- Apply the patch to our working copy
As a one-liner:
git diff -p -R --no-color \ | grep -E "^(diff|(old|new) mode)" --color=never \ | git apply
You can also add it as an alias to your git config…
git config --global --add alias.permission-reset '!git diff -p -R --no-color | grep -E "^(diff|(old|new) mode)" --color=never | git apply'
…and you can invoke it via:
git permission-reset
Note, if your shell is bash, make sure to use
'
instead of"
quotes around the!git
, otherwise it gets substituted with the last git command you ran.
Git make local branch exactly same as remote
Good to clean up some mess that you have accidentally caused on your local branch
I most cases first command is enough
First, reset to the previously fetched HEAD of the corresponding upstream branch:
git reset --hard @{u}
The advantage of specifying @{u} or its verbose form @{upstream} is that the name of the remote repo and branch don’t have to be explicitly specified.
Next, as needed, remove untracked files, optionally also with -x:
git clean -df
Finally, as needed, get the latest changes:
git pull
All in one in single line
git reset --hard @{u} && git clean -df && git pull
Git change author history
Cant remember source
Good in cases, when you accidentally set up wrong email / name in Git config, do some commits with wrong data and then want to fix it.
Note! You have to force push after running it.
git push -f
may result broken history and loss of code, so be careful
git filter-branch --env-filter '
WRONG_EMAIL="[email protected]"
NEW_NAME="New Name Value"
NEW_EMAIL="[email protected]"
if [ "$GIT_COMMITTER_EMAIL" = "$WRONG_EMAIL" ]
then
export GIT_COMMITTER_NAME="$NEW_NAME"
export GIT_COMMITTER_EMAIL="$NEW_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$WRONG_EMAIL" ]
then
export GIT_AUTHOR_NAME="$NEW_NAME"
export GIT_AUTHOR_EMAIL="$NEW_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags
NPM
Run executable files directly from node_modules
It is always better to have dependencies as dev dependencies than install them globally.
There are two ways to execute project dependencies like Mocha, Nyc, ESLint etc.
Let’s use nyc + mocha test running for example
In package.json script it would be like this:
{
"scripts": {
"test": "nyc mocha ./test.js"
}
}
First option - use full paths:
./node_modules/.bin/nyc ./node_modules/.bin/mocha ./test.js
Second option - use npx
npx nyc mocha ./test.js
SSH
Tunnel port from remote to local
Good way to get port from remote server to local. Especially handy when accessing databases on remote that are limited to be accessed from localhost only
Signature:
ssh -L LOCAL_PORT:localhost:REMOTE_PORT USER@SERVER
Getting MySQL port 3306 from remote to local:
ssh -L 3306:localhost:3306 [email protected]
Getting RethinkDB management UI from remote server port 8080 to local port 8085 with ssh alias
ssh -L 8085:localhost:8080 rethinkdb_server
Copy key to remote (ssh-copy-id)
It’s safer and more convenient to use ssh key to log into server compared to password
Signature:
ssh-copy-id USER@SERVER
To copy default
~/.ssh/id_rsa.pub
to remote server:ssh-copy-id [email protected]
To copy some other keyfile to remote server:
ssh-copy-id -i ~/.ssh/awskey.pem.pub [email protected]
773 Words
2019-09-17 23:38 +0000