Mike Hommey: Adding some VCS information in bash prompt
I don’t spend a lot of time customizing my “working” environment nowadays, like enhancing vim configuration, or tweaking the shell. But when I read MadCoder’s zsh git-enabled prompt, I though it was too convenient to not have something like that. Except I don’t work with git only (sadly, but that’s changing), and I don’t like colours in prompt (and a 2 lines prompt is too much).
Anyways, since I have a bunch of directories in my $HOME that contain either svk, svn, mercurial, or git working trees, I thought it would be nice to have some information about all this on my prompt.
After a few iterations, here are the sample results:
The base directory of a git working tree can be deduced from the result of
For the ref, I wanted something like the name of the directory that has been checked out at the top-level directory (usually “trunk” or a branch name), followed by the revision number.
mh@namakemono:~/dd/packages$
mh@namakemono:(svn)~/dd/packages/iceape[trunk:39972]debian/patches$
mh@namakemono:(svk)~/dd/packages/libxml2[trunk:1308]include/libxml$
mh@namakemono:(hg)~/moz/cvs-trunk-mirror[default]uriloader/exthandler$
mh@namakemono:(git)~/git/webkit[debian]JavaScriptCore/wtf$
_bold=$(tput bold)
_normal=$(tput sgr0)
tput is a tool I only dicovered recently, and avoids the need to know the escape codes. There are also options for cursor placement, colours, etc. It lies in the ncurses-bin package, if you want to play with it.
__vcs_dir()
local vcs base_dir sub_dir ref
sub_dir()
local sub_dir
sub_dir=$(readlink -f "$ PWD ")
sub_dir=$ sub_dir#$1
echo $ sub_dir#/
sub_dir is going to be used in several places below, which is why we declare it as a function. It outputs the current directory, relative to the directory given as argument.
git_dir()
base_dir=$(git-rev-parse --show-cdup 2>/dev/null) return 1
base_dir=$(readlink -f "$base_dir/..")
sub_dir=$(git-rev-parse --show-prefix)
sub_dir=$ sub_dir%/
ref=$(git-symbolic-ref -q HEAD git-name-rev --name-only HEAD 2>/dev/null)
ref=$ ref#refs/heads/
vcs="git"
vcs, base_dir, sub_dir and ref. They are, respectively, the VCS type, the top-level directory of the working tree, the current directory, relative to base_dir, and the branch, revision or a reference in the repository, depending on the VCS in use. These functions return 1 if the current directory is not in a working tree of the currently considered VCS.The base directory of a git working tree can be deduced from the result of
git-rev-parse --show-cdup, which gives the way up to the top-level directory, relative to the current directory. readlink -f then gives the canonical top-level directory. The current directory, relative to the top-level, is simply given by git-rev-parse --show-prefix.git-name-rev --name-only HEAD gives a nice reference for the current HEAD, especially if you’re on a detached head. But this can turn out to do a lot of work, introducing a slight lag when you cd for the first time in the git working tree, while most of the time, the HEAD is just a symbolic ref. This is why we first try git-symbolic-ref --name-only HEAD.
svn_dir()
[ -d ".svn" ] return 1
base_dir="."
while [ -d "$base_dir/../.svn" ]; do base_dir="$base_dir/.."; done
base_dir=$(readlink -f "$base_dir")
sub_dir=$(sub_dir "$ base_dir ")
ref=$(svn info "$base_dir" awk '/^URL/ sub(".*/","",$0); r=$0 /^Revision/ sub("[^0-9]*","",$0); print r":"$0 ')
vcs="svn"
.svn directory, be it top-level or sub directory. We look up the top-level directory by checking the last directory containing a .svn sub directory on the way up. This obviously doesn’t work if you checkout under another svn working tree, but I don’t do such things.For the ref, I wanted something like the name of the directory that has been checked out at the top-level directory (usually “trunk” or a branch name), followed by the revision number.
svk_dir()
[ -f ~/.svk/config ] return 1
base_dir=$(awk '/: *$/ sub(/^ */,"",$0); sub(/: *$/,"",$0); if (match("'$ PWD '", $0"(/ $)")) print $0; d=1; /depotpath/ && d == 1 sub(".*/","",$0); r=$0 /revision/ && d == 1 print r ":" $2; exit 1 ' ~/.svk/config) && return 1
ref=$ base_dir##*
base_dir=$ base_dir%%
*
sub_dir=$(sub_dir "$ base_dir ")
vcs="svk"
hg_dir()
base_dir="."
while [ ! -d "$base_dir/.hg" ]; do base_dir="$base_dir/.."; [ $(readlink -f "$ base_dir ") = "/" ] && return 1; done
base_dir=$(readlink -f "$base_dir")
sub_dir=$(sub_dir "$ base_dir ")
ref=$(< "$ base_dir /.hg/branch")
vcs="hg"
git_dir
svn_dir
svk_dir
hg_dir
base_dir="$PWD"
echo "$ vcs:+($vcs) $ _bold $ base_dir/$HOME/~ $ _normal $ vcs:+[$ref]$ _bold $ sub_dir $ _normal "
PS1='$ debian_chroot:+($debian_chroot) \u@\h:$(___vcs_dir)\$ '
I was determined to track the multiple grep issues down, and I was really really really suprised to see there is a testsuite in grep (as the current issues should have been catched easily), but indeed there is one !!!
PS MadCoder: I’m sorry dude, I’m still speaking about Perl 
