contrib/completion/git-prompt.sh - jrn/git - Git at Google

 # bash/zsh git prompt support
 #
 # Copyright (C) 2006,2007 Shawn O. Pearce <spearce@spearce.org>
 # Distributed under the GNU General Public License, version 2.0.
 #
 # This script allows you to see repository status in your prompt.
 #
 # To enable:
 #
 #    1) Copy this file to somewhere (e.g. ~/.git-prompt.sh).
 #    2) Add the following line to your .bashrc/.zshrc:
 #        source ~/.git-prompt.sh
 #    3a) Change your PS1 to call __git_ps1 as
 #        command-substitution:
 #        Bash: PS1='[\u@\h \W$(__git_ps1 " (%s)")]\$ '
 #        ZSH:  setopt PROMPT_SUBST ; PS1='[%n@%m %c$(__git_ps1 " (%s)")]\$ '
 #        the optional argument will be used as format string.
 #    3b) Alternatively, for a slightly faster prompt, __git_ps1 can
 #        be used for PROMPT_COMMAND in Bash or for precmd() in Zsh
 #        with two parameters, <pre> and <post>, which are strings
 #        you would put in $PS1 before and after the status string
 #        generated by the git-prompt machinery.  e.g.
 #        Bash: PROMPT_COMMAND='__git_ps1 "\u@\h:\w" "\\\$ "'
 #          will show username, at-sign, host, colon, cwd, then
 #          various status string, followed by dollar and SP, as
 #          your prompt.
 #        ZSH:  precmd () { __git_ps1 "%n" ":%~$ " "|%s" }
 #          will show username, pipe, then various status string,
 #          followed by colon, cwd, dollar and SP, as your prompt.
 #        Optionally, you can supply a third argument with a printf
 #        format string to finetune the output of the branch status
 #
 # The repository status will be displayed only if you are currently in a
 # git repository. The %s token is the placeholder for the shown status.
 #
 # The prompt status always includes the current branch name.
 #
 # In addition, if you set GIT_PS1_SHOWDIRTYSTATE to a nonempty value,
 # unstaged (*) and staged (+) changes will be shown next to the branch
 # name.  You can configure this per-repository with the
 # bash.showDirtyState variable, which defaults to true once
 # GIT_PS1_SHOWDIRTYSTATE is enabled.
 #
 # You can also see if currently something is stashed, by setting
 # GIT_PS1_SHOWSTASHSTATE to a nonempty value. If something is stashed,
 # then a '$' will be shown next to the branch name.
 #
 # If you would like to see if there're untracked files, then you can set
 # GIT_PS1_SHOWUNTRACKEDFILES to a nonempty value. If there're untracked
 # files, then a '%' will be shown next to the branch name.  You can
 # configure this per-repository with the bash.showUntrackedFiles
 # variable, which defaults to true once GIT_PS1_SHOWUNTRACKEDFILES is
 # enabled.
 #
 # If you would like to see the difference between HEAD and its upstream,
 # set GIT_PS1_SHOWUPSTREAM="auto".  A "<" indicates you are behind, ">"
 # indicates you are ahead, "<>" indicates you have diverged and "="
 # indicates that there is no difference. You can further control
 # behaviour by setting GIT_PS1_SHOWUPSTREAM to a space-separated list
 # of values:
 #
 #     verbose       show number of commits ahead/behind (+/-) upstream
 #     name          if verbose, then also show the upstream abbrev name
 #     legacy        don't use the '--count' option available in recent
 #                   versions of git-rev-list
 #     git           always compare HEAD to @{upstream}
 #     svn           always compare HEAD to your SVN upstream
 #
 # You can change the separator between the branch name and the above
 # state symbols by setting GIT_PS1_STATESEPARATOR. The default separator
 # is SP.
 #
 # By default, __git_ps1 will compare HEAD to your SVN upstream if it can
 # find one, or @{upstream} otherwise.  Once you have set
 # GIT_PS1_SHOWUPSTREAM, you can override it on a per-repository basis by
 # setting the bash.showUpstream config variable.
 #
 # If you would like to see more information about the identity of
 # commits checked out as a detached HEAD, set GIT_PS1_DESCRIBE_STYLE
 # to one of these values:
 #
 #     contains      relative to newer annotated tag (v1.6.3.2~35)
 #     branch        relative to newer tag or branch (master~4)
 #     describe      relative to older annotated tag (v1.6.3.1-13-gdd42c2f)
 #     tag           relative to any older tag (v1.6.3.1-13-gdd42c2f)
 #     default       exactly matching tag
 #
 # If you would like a colored hint about the current dirty state, set
 # GIT_PS1_SHOWCOLORHINTS to a nonempty value. The colors are based on
 # the colored output of "git status -sb" and are available only when
 # using __git_ps1 for PROMPT_COMMAND or precmd.
 #
 # If you would like __git_ps1 to do nothing in the case when the current
 # directory is set up to be ignored by git, then set
 # GIT_PS1_HIDE_IF_PWD_IGNORED to a nonempty value. Override this on the
 # repository level by setting bash.hideIfPwdIgnored to "false".

 # check whether printf supports -v
 __git_printf_supports_v=
 printf -v __git_printf_supports_v -- '%s' yes >/dev/null 2>&1

 # stores the divergence from upstream in $p
 # used by GIT_PS1_SHOWUPSTREAM
 __git_ps1_show_upstream ()
 {
 	local key value
 	local svn_remote svn_url_pattern count n
 	local upstream=git legacy="" verbose="" name=""

 	svn_remote=()
 	# get some config options from git-config
 	local output="$(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')"
 	while read -r key value; do
 		case "$key" in
 		bash.showupstream)
 			GIT_PS1_SHOWUPSTREAM="$value"
 			if [[ -z "${GIT_PS1_SHOWUPSTREAM}" ]]; then
 				p=""
 				return
 			fi
 			;;
 		svn-remote.*.url)
 			svn_remote[$((${#svn_remote[@]} + 1))]="$value"
 			svn_url_pattern="$svn_url_pattern\\|$value"
 			upstream=svn+git # default upstream is SVN if available, else git
 			;;
 		esac
 	done <<< "$output"

 	# parse configuration values
 	for option in ${GIT_PS1_SHOWUPSTREAM}; do
 		case "$option" in
 		git|svn) upstream="$option" ;;
 		verbose) verbose=1 ;;
 		legacy)  legacy=1  ;;
 		name)    name=1 ;;
 		esac
 	done

 	# Find our upstream
 	case "$upstream" in
 	git)    upstream="@{upstream}" ;;
 	svn*)
 		# get the upstream from the "git-svn-id: ..." in a commit message
 		# (git-svn uses essentially the same procedure internally)
 		local -a svn_upstream
 		svn_upstream=($(git log --first-parent -1 \
 					--grep="^git-svn-id: \(${svn_url_pattern#??}\)" 2>/dev/null))
 		if [[ 0 -ne ${#svn_upstream[@]} ]]; then
 			svn_upstream=${svn_upstream[${#svn_upstream[@]} - 2]}
 			svn_upstream=${svn_upstream%@*}
 			local n_stop="${#svn_remote[@]}"
 			for ((n=1; n <= n_stop; n++)); do
 				svn_upstream=${svn_upstream#${svn_remote[$n]}}
 			done

 			if [[ -z "$svn_upstream" ]]; then
 				# default branch name for checkouts with no layout:
 				upstream=${GIT_SVN_ID:-git-svn}
 			else
 				upstream=${svn_upstream#/}
 			fi
 		elif [[ "svn+git" = "$upstream" ]]; then
 			upstream="@{upstream}"
 		fi
 		;;
 	esac

 	# Find how many commits we are ahead/behind our upstream
 	if [[ -z "$legacy" ]]; then
 		count="$(git rev-list --count --left-right \
 				"$upstream"...HEAD 2>/dev/null)"
 	else
 		# produce equivalent output to --count for older versions of git
 		local commits
 		if commits="$(git rev-list --left-right "$upstream"...HEAD 2>/dev/null)"
 		then
 			local commit behind=0 ahead=0
 			for commit in $commits
 			do
 				case "$commit" in
 				"<"*) ((behind++)) ;;
 				*)    ((ahead++))  ;;
 				esac
 			done
 			count="$behind	$ahead"
 		else
 			count=""
 		fi
 	fi

 	# calculate the result
 	if [[ -z "$verbose" ]]; then
 		case "$count" in
 		"") # no upstream
 			p="" ;;
 		"0	0") # equal to upstream
 			p="=" ;;
 		"0	"*) # ahead of upstream
 			p=">" ;;
 		*"	0") # behind upstream
 			p="<" ;;
 		*)	    # diverged from upstream
 			p="<>" ;;
 		esac
 	else
 		case "$count" in
 		"") # no upstream
 			p="" ;;
 		"0	0") # equal to upstream
 			p=" u=" ;;
 		"0	"*) # ahead of upstream
 			p=" u+${count#0	}" ;;
 		*"	0") # behind upstream
 			p=" u-${count%	0}" ;;
 		*)	    # diverged from upstream
 			p=" u+${count#*	}-${count%	*}" ;;
 		esac
 		if [[ -n "$count" && -n "$name" ]]; then
 			__git_ps1_upstream_name=$(git rev-parse \
 				--abbrev-ref "$upstream" 2>/dev/null)
 			if [ $pcmode = yes ] && [ $ps1_expanded = yes ]; then
 				p="$p \${__git_ps1_upstream_name}"
 			else
 				p="$p ${__git_ps1_upstream_name}"
 				# not needed anymore; keep user's
 				# environment clean
 				unset __git_ps1_upstream_name
 			fi
 		fi
 	fi

 }

 # Helper function that is meant to be called from __git_ps1.  It
 # injects color codes into the appropriate gitstring variables used
 # to build a gitstring.
 __git_ps1_colorize_gitstring ()
 {
 	if [[ -n ${ZSH_VERSION-} ]]; then
 		local c_red='%F{red}'
 		local c_green='%F{green}'
 		local c_lblue='%F{blue}'
 		local c_clear='%f'
 	else
 		# Using \[ and \] around colors is necessary to prevent
 		# issues with command line editing/browsing/completion!
 		local c_red='\[\e[31m\]'
 		local c_green='\[\e[32m\]'
 		local c_lblue='\[\e[1;34m\]'
 		local c_clear='\[\e[0m\]'
 	fi
 	local bad_color=$c_red
 	local ok_color=$c_green
 	local flags_color="$c_lblue"

 	local branch_color=""
 	if [ $detached = no ]; then
 		branch_color="$ok_color"
 	else
 		branch_color="$bad_color"
 	fi
 	c="$branch_color$c"

 	z="$c_clear$z"
 	if [ "$w" = "*" ]; then
 		w="$bad_color$w"
 	fi
 	if [ -n "$i" ]; then
 		i="$ok_color$i"
 	fi
 	if [ -n "$s" ]; then
 		s="$flags_color$s"
 	fi
 	if [ -n "$u" ]; then
 		u="$bad_color$u"
 	fi
 	r="$c_clear$r"
 }

 # Helper function to read the first line of a file into a variable.
 # __git_eread requires 2 arguments, the file path and the name of the
 # variable, in that order.
 __git_eread ()
 {
 	test -r "$1" && IFS=$'\r\n' read "$2" <"$1"
 }

 # see if a cherry-pick or revert is in progress, if the user has committed a
 # conflict resolution with 'git commit' in the middle of a sequence of picks or
 # reverts then CHERRY_PICK_HEAD/REVERT_HEAD will not exist so we have to read
 # the todo file.
 __git_sequencer_status ()
 {
 	local todo
 	if test -f "$g/CHERRY_PICK_HEAD"
 	then
 		r="|CHERRY-PICKING"
 		return 0;
 	elif test -f "$g/REVERT_HEAD"
 	then
 		r="|REVERTING"
 		return 0;
 	elif __git_eread "$g/sequencer/todo" todo
 	then
 		case "$todo" in
 		p[\ \	]|pick[\ \	]*)
 			r="|CHERRY-PICKING"
 			return 0
 		;;
 		revert[\ \	]*)
 			r="|REVERTING"
 			return 0
 		;;
 		esac
 	fi
 	return 1
 }

 # __git_ps1 accepts 0 or 1 arguments (i.e., format string)
 # when called from PS1 using command substitution
 # in this mode it prints text to add to bash PS1 prompt (includes branch name)
 #
 # __git_ps1 requires 2 or 3 arguments when called from PROMPT_COMMAND (pc)
 # in that case it _sets_ PS1. The arguments are parts of a PS1 string.
 # when two arguments are given, the first is prepended and the second appended
 # to the state string when assigned to PS1.
 # The optional third parameter will be used as printf format string to further
 # customize the output of the git-status string.
 # In this mode you can request colored hints using GIT_PS1_SHOWCOLORHINTS=true
 __git_ps1 ()
 {
 	# preserve exit status
 	local exit=$?
 	local pcmode=no
 	local detached=no
 	local ps1pc_start='\u@\h:\w '
 	local ps1pc_end='\$ '
 	local printf_format=' (%s)'

 	case "$#" in
 		2|3)	pcmode=yes
 			ps1pc_start="$1"
 			ps1pc_end="$2"
 			printf_format="${3:-$printf_format}"
 			# set PS1 to a plain prompt so that we can
 			# simply return early if the prompt should not
 			# be decorated
 			PS1="$ps1pc_start$ps1pc_end"
 		;;
 		0|1)	printf_format="${1:-$printf_format}"
 		;;
 		*)	return $exit
 		;;
 	esac

 	# ps1_expanded:  This variable is set to 'yes' if the shell
 	# subjects the value of PS1 to parameter expansion:
 	#
 	#   * bash does unless the promptvars option is disabled
 	#   * zsh does not unless the PROMPT_SUBST option is set
 	#   * POSIX shells always do
 	#
 	# If the shell would expand the contents of PS1 when drawing
 	# the prompt, a raw ref name must not be included in PS1.
 	# This protects the user from arbitrary code execution via
 	# specially crafted ref names.  For example, a ref named
 	# 'refs/heads/$(IFS=_;cmd=sudo_rm_-rf_/;$cmd)' might cause the
 	# shell to execute 'sudo rm -rf /' when the prompt is drawn.
 	#
 	# Instead, the ref name should be placed in a separate global
 	# variable (in the __git_ps1_* namespace to avoid colliding
 	# with the user's environment) and that variable should be
 	# referenced from PS1.  For example:
 	#
 	#     __git_ps1_foo=$(do_something_to_get_ref_name)
 	#     PS1="...stuff...\${__git_ps1_foo}...stuff..."
 	#
 	# If the shell does not expand the contents of PS1, the raw
 	# ref name must be included in PS1.
 	#
 	# The value of this variable is only relevant when in pcmode.
 	#
 	# Assume that the shell follows the POSIX specification and
 	# expands PS1 unless determined otherwise.  (This is more
 	# likely to be correct if the user has a non-bash, non-zsh
 	# shell and safer than the alternative if the assumption is
 	# incorrect.)
 	#
 	local ps1_expanded=yes
 	[ -z "${ZSH_VERSION-}" ] || [[ -o PROMPT_SUBST ]] || ps1_expanded=no
 	[ -z "${BASH_VERSION-}" ] || shopt -q promptvars || ps1_expanded=no

 	local repo_info rev_parse_exit_code
 	repo_info="$(git rev-parse --git-dir --is-inside-git-dir \
 		--is-bare-repository --is-inside-work-tree \
 		--short HEAD 2>/dev/null)"
 	rev_parse_exit_code="$?"

 	if [ -z "$repo_info" ]; then
 		return $exit
 	fi

 	local short_sha=""
 	if [ "$rev_parse_exit_code" = "0" ]; then
 		short_sha="${repo_info##*$'\n'}"
 		repo_info="${repo_info%$'\n'*}"
 	fi
 	local inside_worktree="${repo_info##*$'\n'}"
 	repo_info="${repo_info%$'\n'*}"
 	local bare_repo="${repo_info##*$'\n'}"
 	repo_info="${repo_info%$'\n'*}"
 	local inside_gitdir="${repo_info##*$'\n'}"
 	local g="${repo_info%$'\n'*}"

 	if [ "true" = "$inside_worktree" ] &&
 	   [ -n "${GIT_PS1_HIDE_IF_PWD_IGNORED-}" ] &&
 	   [ "$(git config --bool bash.hideIfPwdIgnored)" != "false" ] &&
 	   git check-ignore -q .
 	then
 		return $exit
 	fi

 	local r=""
 	local b=""
 	local step=""
 	local total=""
 	if [ -d "$g/rebase-merge" ]; then
 		__git_eread "$g/rebase-merge/head-name" b
 		__git_eread "$g/rebase-merge/msgnum" step
 		__git_eread "$g/rebase-merge/end" total
 		if [ -f "$g/rebase-merge/interactive" ]; then
 			r="|REBASE-i"
 		else
 			r="|REBASE-m"
 		fi
 	else
 		if [ -d "$g/rebase-apply" ]; then
 			__git_eread "$g/rebase-apply/next" step
 			__git_eread "$g/rebase-apply/last" total
 			if [ -f "$g/rebase-apply/rebasing" ]; then
 				__git_eread "$g/rebase-apply/head-name" b
 				r="|REBASE"
 			elif [ -f "$g/rebase-apply/applying" ]; then
 				r="|AM"
 			else
 				r="|AM/REBASE"
 			fi
 		elif [ -f "$g/MERGE_HEAD" ]; then
 			r="|MERGING"
 		elif __git_sequencer_status; then
 			:
 		elif [ -f "$g/BISECT_LOG" ]; then
 			r="|BISECTING"
 		fi

 		if [ -n "$b" ]; then
 			:
 		elif [ -h "$g/HEAD" ]; then
 			# symlink symbolic ref
 			b="$(git symbolic-ref HEAD 2>/dev/null)"
 		else
 			local head=""
 			if ! __git_eread "$g/HEAD" head; then
 				return $exit
 			fi
 			# is it a symbolic ref?
 			b="${head#ref: }"
 			if [ "$head" = "$b" ]; then
 				detached=yes
 				b="$(
 				case "${GIT_PS1_DESCRIBE_STYLE-}" in
 				(contains)
 					git describe --contains HEAD ;;
 				(branch)
 					git describe --contains --all HEAD ;;
 				(tag)
 					git describe --tags HEAD ;;
 				(describe)
 					git describe HEAD ;;
 				(* | default)
 					git describe --tags --exact-match HEAD ;;
 				esac 2>/dev/null)" ||

 				b="$short_sha..."
 				b="($b)"
 			fi
 		fi
 	fi

 	if [ -n "$step" ] && [ -n "$total" ]; then
 		r="$r $step/$total"
 	fi

 	local w=""
 	local i=""
 	local s=""
 	local u=""
 	local c=""
 	local p=""

 	if [ "true" = "$inside_gitdir" ]; then
 		if [ "true" = "$bare_repo" ]; then
 			c="BARE:"
 		else
 			b="GIT_DIR!"
 		fi
 	elif [ "true" = "$inside_worktree" ]; then
 		if [ -n "${GIT_PS1_SHOWDIRTYSTATE-}" ] &&
 		   [ "$(git config --bool bash.showDirtyState)" != "false" ]
 		then
 			git diff --no-ext-diff --quiet || w="*"
 			git diff --no-ext-diff --cached --quiet || i="+"
 			if [ -z "$short_sha" ] && [ -z "$i" ]; then
 				i="#"
 			fi
 		fi
 		if [ -n "${GIT_PS1_SHOWSTASHSTATE-}" ] &&
 		   git rev-parse --verify --quiet refs/stash >/dev/null
 		then
 			s="$"
 		fi

 		if [ -n "${GIT_PS1_SHOWUNTRACKEDFILES-}" ] &&
 		   [ "$(git config --bool bash.showUntrackedFiles)" != "false" ] &&
 		   git ls-files --others --exclude-standard --directory --no-empty-directory --error-unmatch -- ':/*' >/dev/null 2>/dev/null
 		then
 			u="%${ZSH_VERSION+%}"
 		fi

 		if [ -n "${GIT_PS1_SHOWUPSTREAM-}" ]; then
 			__git_ps1_show_upstream
 		fi
 	fi

 	local z="${GIT_PS1_STATESEPARATOR-" "}"

 	# NO color option unless in PROMPT_COMMAND mode
 	if [ $pcmode = yes ] && [ -n "${GIT_PS1_SHOWCOLORHINTS-}" ]; then
 		__git_ps1_colorize_gitstring
 	fi

 	b=${b##refs/heads/}
 	if [ $pcmode = yes ] && [ $ps1_expanded = yes ]; then
 		__git_ps1_branch_name=$b
 		b="\${__git_ps1_branch_name}"
 	fi

 	local f="$w$i$s$u"
 	local gitstring="$c$b${f:+$z$f}$r$p"

 	if [ $pcmode = yes ]; then
 		if [ "${__git_printf_supports_v-}" != yes ]; then
 			gitstring=$(printf -- "$printf_format" "$gitstring")
 		else
 			printf -v gitstring -- "$printf_format" "$gitstring"
 		fi
 		PS1="$ps1pc_start$gitstring$ps1pc_end"
 	else
 		printf -- "$printf_format" "$gitstring"
 	fi

 	return $exit
 }
	# bash/zsh git prompt support
	#
	# Copyright (C) 2006,2007 Shawn O. Pearce <spearce@spearce.org>
	# Distributed under the GNU General Public License, version 2.0.
	#
	# This script allows you to see repository status in your prompt.
	#
	# To enable:
	#
	# 1) Copy this file to somewhere (e.g. ~/.git-prompt.sh).
	# 2) Add the following line to your .bashrc/.zshrc:
	# source ~/.git-prompt.sh
	# 3a) Change your PS1 to call __git_ps1 as
	# command-substitution:
	# Bash: PS1='[\u@\h \W$(__git_ps1 " (%s)")]\$ '
	# ZSH: setopt PROMPT_SUBST ; PS1='[%n@%m %c$(__git_ps1 " (%s)")]\$ '
	# the optional argument will be used as format string.
	# 3b) Alternatively, for a slightly faster prompt, __git_ps1 can
	# be used for PROMPT_COMMAND in Bash or for precmd() in Zsh
	# with two parameters, <pre> and <post>, which are strings
	# you would put in $PS1 before and after the status string
	# generated by the git-prompt machinery. e.g.
	# Bash: PROMPT_COMMAND='__git_ps1 "\u@\h:\w" "\\\$ "'
	# will show username, at-sign, host, colon, cwd, then
	# various status string, followed by dollar and SP, as
	# your prompt.
	# ZSH: precmd () { __git_ps1 "%n" ":%~$ " "\|%s" }
	# will show username, pipe, then various status string,
	# followed by colon, cwd, dollar and SP, as your prompt.
	# Optionally, you can supply a third argument with a printf
	# format string to finetune the output of the branch status
	#
	# The repository status will be displayed only if you are currently in a
	# git repository. The %s token is the placeholder for the shown status.
	#
	# The prompt status always includes the current branch name.
	#
	# In addition, if you set GIT_PS1_SHOWDIRTYSTATE to a nonempty value,
	# unstaged (*) and staged (+) changes will be shown next to the branch
	# name. You can configure this per-repository with the
	# bash.showDirtyState variable, which defaults to true once
	# GIT_PS1_SHOWDIRTYSTATE is enabled.
	#
	# You can also see if currently something is stashed, by setting
	# GIT_PS1_SHOWSTASHSTATE to a nonempty value. If something is stashed,
	# then a '$' will be shown next to the branch name.
	#
	# If you would like to see if there're untracked files, then you can set
	# GIT_PS1_SHOWUNTRACKEDFILES to a nonempty value. If there're untracked
	# files, then a '%' will be shown next to the branch name. You can
	# configure this per-repository with the bash.showUntrackedFiles
	# variable, which defaults to true once GIT_PS1_SHOWUNTRACKEDFILES is
	# enabled.
	#
	# If you would like to see the difference between HEAD and its upstream,
	# set GIT_PS1_SHOWUPSTREAM="auto". A "<" indicates you are behind, ">"
	# indicates you are ahead, "<>" indicates you have diverged and "="
	# indicates that there is no difference. You can further control
	# behaviour by setting GIT_PS1_SHOWUPSTREAM to a space-separated list
	# of values:
	#
	# verbose show number of commits ahead/behind (+/-) upstream
	# name if verbose, then also show the upstream abbrev name
	# legacy don't use the '--count' option available in recent
	# versions of git-rev-list
	# git always compare HEAD to @{upstream}
	# svn always compare HEAD to your SVN upstream
	#
	# You can change the separator between the branch name and the above
	# state symbols by setting GIT_PS1_STATESEPARATOR. The default separator
	# is SP.
	#
	# By default, __git_ps1 will compare HEAD to your SVN upstream if it can
	# find one, or @{upstream} otherwise. Once you have set
	# GIT_PS1_SHOWUPSTREAM, you can override it on a per-repository basis by
	# setting the bash.showUpstream config variable.
	#
	# If you would like to see more information about the identity of
	# commits checked out as a detached HEAD, set GIT_PS1_DESCRIBE_STYLE
	# to one of these values:
	#
	# contains relative to newer annotated tag (v1.6.3.2~35)
	# branch relative to newer tag or branch (master~4)
	# describe relative to older annotated tag (v1.6.3.1-13-gdd42c2f)
	# tag relative to any older tag (v1.6.3.1-13-gdd42c2f)
	# default exactly matching tag
	#
	# If you would like a colored hint about the current dirty state, set
	# GIT_PS1_SHOWCOLORHINTS to a nonempty value. The colors are based on
	# the colored output of "git status -sb" and are available only when
	# using __git_ps1 for PROMPT_COMMAND or precmd.
	#
	# If you would like __git_ps1 to do nothing in the case when the current
	# directory is set up to be ignored by git, then set
	# GIT_PS1_HIDE_IF_PWD_IGNORED to a nonempty value. Override this on the
	# repository level by setting bash.hideIfPwdIgnored to "false".

	# check whether printf supports -v
	__git_printf_supports_v=
	printf -v __git_printf_supports_v -- '%s' yes >/dev/null 2>&1

	# stores the divergence from upstream in $p
	# used by GIT_PS1_SHOWUPSTREAM
	__git_ps1_show_upstream ()
	{
	local key value
	local svn_remote svn_url_pattern count n
	local upstream=git legacy="" verbose="" name=""

	svn_remote=()
	# get some config options from git-config
	local output="$(git config -z --get-regexp '^(svn-remote\..*\.url\|bash\.showupstream)$' 2>/dev/null \| tr '\0\n' '\n ')"
	while read -r key value; do
	case "$key" in
	bash.showupstream)
	GIT_PS1_SHOWUPSTREAM="$value"
	if [[ -z "${GIT_PS1_SHOWUPSTREAM}" ]]; then
	p=""
	return
	fi
	;;
	svn-remote.*.url)
	svn_remote[$((${#svn_remote[@]} + 1))]="$value"
	svn_url_pattern="$svn_url_pattern\\\|$value"
	upstream=svn+git # default upstream is SVN if available, else git
	;;
	esac
	done <<< "$output"

	# parse configuration values
	for option in ${GIT_PS1_SHOWUPSTREAM}; do
	case "$option" in
	git\|svn) upstream="$option" ;;
	verbose) verbose=1 ;;
	legacy) legacy=1 ;;
	name) name=1 ;;
	esac
	done

	# Find our upstream
	case "$upstream" in
	git) upstream="@{upstream}" ;;
	svn*)
	# get the upstream from the "git-svn-id: ..." in a commit message
	# (git-svn uses essentially the same procedure internally)
	local -a svn_upstream
	svn_upstream=($(git log --first-parent -1 \
	--grep="^git-svn-id: \(${svn_url_pattern#??}\)" 2>/dev/null))
	if [[ 0 -ne ${#svn_upstream[@]} ]]; then
	svn_upstream=${svn_upstream[${#svn_upstream[@]} - 2]}
	svn_upstream=${svn_upstream%@*}
	local n_stop="${#svn_remote[@]}"
	for ((n=1; n <= n_stop; n++)); do
	svn_upstream=${svn_upstream#${svn_remote[$n]}}
	done

	if [[ -z "$svn_upstream" ]]; then
	# default branch name for checkouts with no layout:
	upstream=${GIT_SVN_ID:-git-svn}
	else
	upstream=${svn_upstream#/}
	fi
	elif [[ "svn+git" = "$upstream" ]]; then
	upstream="@{upstream}"
	fi
	;;
	esac

	# Find how many commits we are ahead/behind our upstream
	if [[ -z "$legacy" ]]; then
	count="$(git rev-list --count --left-right \
	"$upstream"...HEAD 2>/dev/null)"
	else
	# produce equivalent output to --count for older versions of git
	local commits
	if commits="$(git rev-list --left-right "$upstream"...HEAD 2>/dev/null)"
	then
	local commit behind=0 ahead=0
	for commit in $commits
	do
	case "$commit" in
	"<"*) ((behind++)) ;;
	*) ((ahead++)) ;;
	esac
	done
	count="$behind $ahead"
	else
	count=""
	fi
	fi

	# calculate the result
	if [[ -z "$verbose" ]]; then
	case "$count" in
	"") # no upstream
	p="" ;;
	"0 0") # equal to upstream
	p="=" ;;
	"0 "*) # ahead of upstream
	p=">" ;;
	*" 0") # behind upstream
	p="<" ;;
	*) # diverged from upstream
	p="<>" ;;
	esac
	else
	case "$count" in
	"") # no upstream
	p="" ;;
	"0 0") # equal to upstream
	p=" u=" ;;
	"0 "*) # ahead of upstream
	p=" u+${count#0 }" ;;
	*" 0") # behind upstream
	p=" u-${count% 0}" ;;
	*) # diverged from upstream
	p=" u+${count#* }-${count% *}" ;;
	esac
	if [[ -n "$count" && -n "$name" ]]; then
	__git_ps1_upstream_name=$(git rev-parse \
	--abbrev-ref "$upstream" 2>/dev/null)
	if [ $pcmode = yes ] && [ $ps1_expanded = yes ]; then
	p="$p \${__git_ps1_upstream_name}"
	else
	p="$p ${__git_ps1_upstream_name}"
	# not needed anymore; keep user's
	# environment clean
	unset __git_ps1_upstream_name
	fi
	fi
	fi

	}

	# Helper function that is meant to be called from __git_ps1. It
	# injects color codes into the appropriate gitstring variables used
	# to build a gitstring.
	__git_ps1_colorize_gitstring ()
	{
	if [[ -n ${ZSH_VERSION-} ]]; then
	local c_red='%F{red}'
	local c_green='%F{green}'
	local c_lblue='%F{blue}'
	local c_clear='%f'
	else
	# Using \[ and \] around colors is necessary to prevent
	# issues with command line editing/browsing/completion!
	local c_red='\[\e[31m\]'
	local c_green='\[\e[32m\]'
	local c_lblue='\[\e[1;34m\]'
	local c_clear='\[\e[0m\]'
	fi
	local bad_color=$c_red
	local ok_color=$c_green
	local flags_color="$c_lblue"

	local branch_color=""
	if [ $detached = no ]; then
	branch_color="$ok_color"
	else
	branch_color="$bad_color"
	fi
	c="$branch_color$c"

	z="$c_clear$z"
	if [ "$w" = "*" ]; then
	w="$bad_color$w"
	fi
	if [ -n "$i" ]; then
	i="$ok_color$i"
	fi
	if [ -n "$s" ]; then
	s="$flags_color$s"
	fi
	if [ -n "$u" ]; then
	u="$bad_color$u"
	fi
	r="$c_clear$r"
	}

	# Helper function to read the first line of a file into a variable.
	# __git_eread requires 2 arguments, the file path and the name of the
	# variable, in that order.
	__git_eread ()
	{
	test -r "$1" && IFS=$'\r\n' read "$2" <"$1"
	}

	# see if a cherry-pick or revert is in progress, if the user has committed a
	# conflict resolution with 'git commit' in the middle of a sequence of picks or
	# reverts then CHERRY_PICK_HEAD/REVERT_HEAD will not exist so we have to read
	# the todo file.
	__git_sequencer_status ()
	{
	local todo
	if test -f "$g/CHERRY_PICK_HEAD"
	then
	r="\|CHERRY-PICKING"
	return 0;
	elif test -f "$g/REVERT_HEAD"
	then
	r="\|REVERTING"
	return 0;
	elif __git_eread "$g/sequencer/todo" todo
	then
	case "$todo" in
	p[\ \ ]\|pick[\ \ ]*)
	r="\|CHERRY-PICKING"
	return 0
	;;
	revert[\ \ ]*)
	r="\|REVERTING"
	return 0
	;;
	esac
	fi
	return 1
	}

	# __git_ps1 accepts 0 or 1 arguments (i.e., format string)
	# when called from PS1 using command substitution
	# in this mode it prints text to add to bash PS1 prompt (includes branch name)
	#
	# __git_ps1 requires 2 or 3 arguments when called from PROMPT_COMMAND (pc)
	# in that case it _sets_ PS1. The arguments are parts of a PS1 string.
	# when two arguments are given, the first is prepended and the second appended
	# to the state string when assigned to PS1.
	# The optional third parameter will be used as printf format string to further
	# customize the output of the git-status string.
	# In this mode you can request colored hints using GIT_PS1_SHOWCOLORHINTS=true
	__git_ps1 ()
	{
	# preserve exit status
	local exit=$?
	local pcmode=no
	local detached=no
	local ps1pc_start='\u@\h:\w '
	local ps1pc_end='\$ '
	local printf_format=' (%s)'

	case "$#" in
	2\|3) pcmode=yes
	ps1pc_start="$1"
	ps1pc_end="$2"
	printf_format="${3:-$printf_format}"
	# set PS1 to a plain prompt so that we can
	# simply return early if the prompt should not
	# be decorated
	PS1="$ps1pc_start$ps1pc_end"
	;;
	0\|1) printf_format="${1:-$printf_format}"
	;;
	*) return $exit
	;;
	esac

	# ps1_expanded: This variable is set to 'yes' if the shell
	# subjects the value of PS1 to parameter expansion:
	#
	# * bash does unless the promptvars option is disabled
	# * zsh does not unless the PROMPT_SUBST option is set
	# * POSIX shells always do
	#
	# If the shell would expand the contents of PS1 when drawing
	# the prompt, a raw ref name must not be included in PS1.
	# This protects the user from arbitrary code execution via
	# specially crafted ref names. For example, a ref named
	# 'refs/heads/$(IFS=_;cmd=sudo_rm_-rf_/;$cmd)' might cause the
	# shell to execute 'sudo rm -rf /' when the prompt is drawn.
	#
	# Instead, the ref name should be placed in a separate global
	# variable (in the __git_ps1_* namespace to avoid colliding
	# with the user's environment) and that variable should be
	# referenced from PS1. For example:
	#
	# __git_ps1_foo=$(do_something_to_get_ref_name)
	# PS1="...stuff...\${__git_ps1_foo}...stuff..."
	#
	# If the shell does not expand the contents of PS1, the raw
	# ref name must be included in PS1.
	#
	# The value of this variable is only relevant when in pcmode.
	#
	# Assume that the shell follows the POSIX specification and
	# expands PS1 unless determined otherwise. (This is more
	# likely to be correct if the user has a non-bash, non-zsh
	# shell and safer than the alternative if the assumption is
	# incorrect.)
	#
	local ps1_expanded=yes
	[ -z "${ZSH_VERSION-}" ] \|\| [[ -o PROMPT_SUBST ]] \|\| ps1_expanded=no
	[ -z "${BASH_VERSION-}" ] \|\| shopt -q promptvars \|\| ps1_expanded=no

	local repo_info rev_parse_exit_code
	repo_info="$(git rev-parse --git-dir --is-inside-git-dir \
	--is-bare-repository --is-inside-work-tree \
	--short HEAD 2>/dev/null)"
	rev_parse_exit_code="$?"

	if [ -z "$repo_info" ]; then
	return $exit
	fi

	local short_sha=""
	if [ "$rev_parse_exit_code" = "0" ]; then
	short_sha="${repo_info##*$'\n'}"
	repo_info="${repo_info%$'\n'*}"
	fi
	local inside_worktree="${repo_info##*$'\n'}"
	repo_info="${repo_info%$'\n'*}"
	local bare_repo="${repo_info##*$'\n'}"
	repo_info="${repo_info%$'\n'*}"
	local inside_gitdir="${repo_info##*$'\n'}"
	local g="${repo_info%$'\n'*}"

	if [ "true" = "$inside_worktree" ] &&
	[ -n "${GIT_PS1_HIDE_IF_PWD_IGNORED-}" ] &&
	[ "$(git config --bool bash.hideIfPwdIgnored)" != "false" ] &&
	git check-ignore -q .
	then
	return $exit
	fi

	local r=""
	local b=""
	local step=""
	local total=""
	if [ -d "$g/rebase-merge" ]; then
	__git_eread "$g/rebase-merge/head-name" b
	__git_eread "$g/rebase-merge/msgnum" step
	__git_eread "$g/rebase-merge/end" total
	if [ -f "$g/rebase-merge/interactive" ]; then
	r="\|REBASE-i"
	else
	r="\|REBASE-m"
	fi
	else
	if [ -d "$g/rebase-apply" ]; then
	__git_eread "$g/rebase-apply/next" step
	__git_eread "$g/rebase-apply/last" total
	if [ -f "$g/rebase-apply/rebasing" ]; then
	__git_eread "$g/rebase-apply/head-name" b
	r="\|REBASE"
	elif [ -f "$g/rebase-apply/applying" ]; then
	r="\|AM"
	else
	r="\|AM/REBASE"
	fi
	elif [ -f "$g/MERGE_HEAD" ]; then
	r="\|MERGING"
	elif __git_sequencer_status; then
	:
	elif [ -f "$g/BISECT_LOG" ]; then
	r="\|BISECTING"
	fi

	if [ -n "$b" ]; then
	:
	elif [ -h "$g/HEAD" ]; then
	# symlink symbolic ref
	b="$(git symbolic-ref HEAD 2>/dev/null)"
	else
	local head=""
	if ! __git_eread "$g/HEAD" head; then
	return $exit
	fi
	# is it a symbolic ref?
	b="${head#ref: }"
	if [ "$head" = "$b" ]; then
	detached=yes
	b="$(
	case "${GIT_PS1_DESCRIBE_STYLE-}" in
	(contains)
	git describe --contains HEAD ;;
	(branch)
	git describe --contains --all HEAD ;;
	(tag)
	git describe --tags HEAD ;;
	(describe)
	git describe HEAD ;;
	(* \| default)
	git describe --tags --exact-match HEAD ;;
	esac 2>/dev/null)" \|\|

	b="$short_sha..."
	b="($b)"
	fi
	fi
	fi

	if [ -n "$step" ] && [ -n "$total" ]; then
	r="$r $step/$total"
	fi

	local w=""
	local i=""
	local s=""
	local u=""
	local c=""
	local p=""

	if [ "true" = "$inside_gitdir" ]; then
	if [ "true" = "$bare_repo" ]; then
	c="BARE:"
	else
	b="GIT_DIR!"
	fi
	elif [ "true" = "$inside_worktree" ]; then
	if [ -n "${GIT_PS1_SHOWDIRTYSTATE-}" ] &&
	[ "$(git config --bool bash.showDirtyState)" != "false" ]
	then
	git diff --no-ext-diff --quiet \|\| w="*"
	git diff --no-ext-diff --cached --quiet \|\| i="+"
	if [ -z "$short_sha" ] && [ -z "$i" ]; then
	i="#"
	fi
	fi
	if [ -n "${GIT_PS1_SHOWSTASHSTATE-}" ] &&
	git rev-parse --verify --quiet refs/stash >/dev/null
	then
	s="$"
	fi

	if [ -n "${GIT_PS1_SHOWUNTRACKEDFILES-}" ] &&
	[ "$(git config --bool bash.showUntrackedFiles)" != "false" ] &&
	git ls-files --others --exclude-standard --directory --no-empty-directory --error-unmatch -- ':/*' >/dev/null 2>/dev/null
	then
	u="%${ZSH_VERSION+%}"
	fi

	if [ -n "${GIT_PS1_SHOWUPSTREAM-}" ]; then
	__git_ps1_show_upstream
	fi
	fi

	local z="${GIT_PS1_STATESEPARATOR-" "}"

	# NO color option unless in PROMPT_COMMAND mode
	if [ $pcmode = yes ] && [ -n "${GIT_PS1_SHOWCOLORHINTS-}" ]; then
	__git_ps1_colorize_gitstring
	fi

	b=${b##refs/heads/}
	if [ $pcmode = yes ] && [ $ps1_expanded = yes ]; then
	__git_ps1_branch_name=$b
	b="\${__git_ps1_branch_name}"
	fi

	local f="$w$i$s$u"
	local gitstring="$c$b${f:+$z$f}$r$p"

	if [ $pcmode = yes ]; then
	if [ "${__git_printf_supports_v-}" != yes ]; then
	gitstring=$(printf -- "$printf_format" "$gitstring")
	else
	printf -v gitstring -- "$printf_format" "$gitstring"
	fi
	PS1="$ps1pc_start$gitstring$ps1pc_end"
	else
	printf -- "$printf_format" "$gitstring"
	fi

	return $exit
	}