For revert the changes to a file in a commit, from https://stackoverflow.com/a/2620822/156458#!/bin/bashfunction output_help {    echo usage: git-revert-single-file <sha1> <file>}sha1=$1file=$2if [[ $sha1 ]]; thengit diff $sha1..$sha1^ -- $file | patch -p1elseoutput_helpfiWhy is -p1 to patch in git diff $sha1..$sha1^ -- $file | patch -p1Thanks.
Why is `-p1` to `patch` here?
git;diff;patch