Linux
git: How to revert a file to a specific commit
October 19, 2015 | 
Author git checkout COMMIT_HASH file/to/revert |
Will bring the file/to/revert file to the state in COMMIT_HASH commit.
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git: Completely revert the last commit
git reset --hard HEAD~1 |
will completely revert the last commit (i.e., everything from this commit will disappear).
git: How to checkout a specific commit/version to a new branch
git checkout -b branch--new commit-hash |
will checkout the commit-hash commit in a new branch called branch-new.
git: How to push a new branch to a remote repository
git push -u REMOTE BRANCH_NAME |
This will also create an association between the local and the remote branch, so you can afterwards just issue git push.
git: How to merge two commits into one
git rebase -i |
and then pick the one you want to keep and squash the other
Pattern Matching Hyphen-Minus Sign in Bash
I was trying to use the sed command to perform some changes to a text and stepped into an interesting “problem”; pattern matching the minus-hyphen (-) symbol.
Assume we have the following text:
something SoMeThiNg some-thing soMe_thing
and we want to match all the different versions of the word with one expression (one by one).
My initial idea was to use this regular expression:
's/[a-zA-Z\-\_]*/matched/' |
Naturally, I tried to escape the – sign. As you can see from the output, this doesn’t work:
$ sed 's/[a-zA-Z\-\_]*/matched/' test matched matched matched-thing matched |
The minus sign is not matched, because of its special meaning (setting ranges). In order to make the expression work, you need to move the “-” either in the beginning or in the end of the expression:
$ sed 's/[a-zA-Z\_-]*/matched/' test matched matched matched matched $ sed 's/[-a-zA-Z\_]*/matched/' test matched matched matched matched |
and leave it un-escaped!