From fba9cf714413ace2bbd92387a7e8517409a86fed Mon Sep 17 00:00:00 2001 From: Zhiming Wang Date: Tue, 8 Dec 2015 00:17:54 -0800 Subject: 20151208 Safeguarding git repos against accidental rm --- ...safeguarding-git-repos-against-accidental-rm.md | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 source/blog/2015-12-08-safeguarding-git-repos-against-accidental-rm.md diff --git a/source/blog/2015-12-08-safeguarding-git-repos-against-accidental-rm.md b/source/blog/2015-12-08-safeguarding-git-repos-against-accidental-rm.md new file mode 100644 index 00000000..8a5f1ae6 --- /dev/null +++ b/source/blog/2015-12-08-safeguarding-git-repos-against-accidental-rm.md @@ -0,0 +1,42 @@ +--- +title: "Safeguarding git repos against accidental rm" +date: 2015-12-08T00:17:39-08:00 +date_display: December 8, 2015 +--- +Everyone who has spent a sizable portion of their life in terminals has experienced that "oh shit" moment: you realize what you've done immediately after you've hit enter, but it's already too late. And needlessly to say, many of those are associated to accidental `rm`s. + +I just had one of those moments. I was going to delete a subdirectory of `~/.config`, but hit return prematurely, and the command line ended up being `rm -r ~/.config`. Imagine the horror one second later. Fortunately I was saved by the read-only objects in `.git`, which triggered prompts; however, damage was already done, to some extent. I had to reinit the repo and do a hard reset, and a corrupted submodule was in my way (it blocked my attempt of `git reset --hard`) which I eventually had to completely remove and re-add. In the end everything was recovered (hopefully) and back to normal, but this episode was definitely not great for heart health, which led me to rethink `rm`. + +I've tried several safer `rm` solutions before. The first and obvious is to alias `rm` to `rm -i`, but having to answer dozens of prompts a day (or more) is agonizing and unproductive. I've also tried trashing, but a nonempty trash can makes me sick, so not for me either. I also used `safe-rm` for a couple of months, but without supplying my own blacklist (I have none to be blacklisted), I've never hit the default blacklist; apparently I'm not stupid enough to mess in system locations, so this won't really help much. Fortunately though, this time I might have found a very good solution for myself. + +The idea is to protect all git repos. Git repos[^repo] are among the most valuable assets of programmers, and they have the nice property of not being completely removable without `-f` or `--force` (the work tree of a submodule, where `.git` is a regular file containing the relative path of the git dir, can be removed without `--force`, but we don't want to damage submodules anyway, so let's not single them out). It's unlikely that we would intend to remove a repo directory without specifying `-f` or `--force`, so let's just reject all such `rm` calls. + +The wrapper is very easy to write. Here's one implementation for Zsh with support for both GNU coreutils and BSD `rm`. + +[^repo]: In this article, "repo" stands for the work tree of a repo, unless otherwise noted; the actual repo with git objects is referred to as "git dir". + +```zsh +rm () { + setopt localoptions noshwordsplit noksharrays + local args_backup force + set -A args_backup $@ + while :; do + case $1 in + --force|-*f*) force=1 && shift;; + --) shift && break;; + -*) shift;; + *) break;; + esac + done + for node; do + # -f, --force hasn't been specified && node is a git repo + [[ -z $force && -e $node/.git ]] && { + printf "\e[31m'%s' is a git repo -- won't remove without the -f or --force option" $node + return 1 + } + done + command rm $args_backup +} +``` + +Personally, I stick it into a [Prezto module](https://github.com/zmwangx/prezto/tree/master/modules/rm_guard) available from my fork. Hopefully it will serve me well this time round. -- cgit v1.2.1