emacs in mac os

use this emacs version from eamcsformacosx. sometime, if os x complains the version, use an old version. also, brew install emacs will install core, only in the terminal. you can view them as two separate emacs. to use gui, one need permissions, grant disk access to /usr/bin/ruby and emacs. to see /usr/bin/ruby, press ctrl+cmd+period to …

split and merge tar.gz file

split: tar -czf – ~/work | split –bytes=100MB – ~/workspaces.tar.gz https://learner.coursera.help/hc/en-us/articles/360004990332-Download-Jupyter-Workspace-files merge cat *.tar.gz* | tar xvfz – https://stackoverflow.com/questions/38199571/untar-multiple-tar-gz-aa-tar-gz-ab-pattern-files

modify a specified commit in git

First rebase to the commit right before the one you want to change. Make the change. Commit. Rebase back. http://stackoverflow.com/questions/1186535/how-to-modify-a-specified-commit  You can use git rebase, for example, if you want to modify back to commit bbc643cd, run $ git rebase –interactive bbc643cd^ In the default editor, modify ‘pick’ to ‘edit’ in the line whose commit you …