git ps1 to display branch name info for bash, works on debian, arch

gitps1.sh

#__git_sequencer_status is a function
function __git_sequencer_status () 
{ 
    local todo;
    if test -f "$g/CHERRY_PICK_HEAD"; then
        r="|CHERRY-PICKING";
        return 0;
    else
        if test -f "$g/REVERT_HEAD"; then
            r="|REVERTING";
            return 0;
        else
            if __git_eread "$g/sequencer/todo" todo; then
                case "$todo" in 
                    p[\ \	] | pick[\ \	]*)
                        r="|CHERRY-PICKING";
                        return 0
                    ;;
                    revert[\ \	]*)
                        r="|REVERTING";
                        return 0
                    ;;
                esac;
            fi;
        fi;
    fi;
    return 1
}
# __git_eread is a function
function __git_eread () 
{ 
    test -r "$1" && IFS='
' read "$2" < "$1"
}
# __git_ps1 is a function
function __git_ps1 () 
{ 
    local exit=$?;
    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:-$printf_format}";
            PS1="$ps1pc_start$ps1pc_end"
        ;;
        0 | 1)
            printf_format="${1:-$printf_format}"
        ;;
        *)
            return $exit
        ;;
    esac;
    local ps1_expanded=yes;
    [ -z "${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="${repo_info##*
}";
        repo_info="${repo_info%
*}";
    fi;
    local inside_worktree="${repo_info##*
}";
    repo_info="${repo_info%
*}";
    local bare_repo="${repo_info##*
}";
    repo_info="${repo_info%
*}";
    local inside_gitdir="${repo_info##*
}";
    local g="${repo_info%
*}";
    if [ "true" = "$inside_worktree" ] && [ -n "${GIT_PS1_HIDE_IF_PWD_IGNORED-}" ] && [ "$(git config --bool bash.hideIfPwdIgnored)" != "false" ] && git check-ignore -q .; then
        return $exit;
    fi;
    local sparse="";
    if [ -z "${GIT_PS1_COMPRESSSPARSESTATE-}" ] && [ -z "${GIT_PS1_OMITSPARSESTATE-}" ] && [ "$(git config --bool core.sparseCheckout)" = "true" ]; then
        sparse="|SPARSE";
    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;
        r="|REBASE";
    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 "$g/rebase-apply/head-name" b;
                r="|REBASE";
            else
                if [ -f "$g/rebase-apply/applying" ]; then
                    r="|AM";
                else
                    r="|AM/REBASE";
                fi;
            fi;
        else
            if [ -f "$g/MERGE_HEAD" ]; then
                r="|MERGING";
            else
                if __git_sequencer_status; then
                    :;
                else
                    if [ -f "$g/BISECT_LOG" ]; then
                        r="|BISECTING";
                    fi;
                fi;
            fi;
        fi;
        if [ -n "$b" ]; then
            :;
        else
            if [ -h "$g/HEAD" ]; then
                b="$(git symbolic-ref HEAD 2>/dev/null)";
            else
                local head="";
                if ! __git_eread "$g/HEAD" head; then
                    return $exit;
                fi;
                b="${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;
    fi;
    if [ -n "$step" ] && [ -n "$total" ]; then
        r="$r $step/$total";
    fi;
    local w="";
    local i="";
    local s="";
    local u="";
    local h="";
    local c="";
    local p="";
    if [ "true" = "$inside_gitdir" ]; then
        if [ "true" = "$bare_repo" ]; then
            c="BARE:";
        else
            b="GIT_DIR!";
        fi;
    else
        if [ "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 "${GIT_PS1_COMPRESSSPARSESTATE-}" ] && [ "$(git config --bool core.sparseCheckout)" = "true" ]; then
                h="?";
            fi;
            if [ -n "${GIT_PS1_SHOWUPSTREAM-}" ]; then
                __git_ps1_show_upstream;
            fi;
        fi;
    fi;
    local z="${GIT_PS1_STATESEPARATOR-" "}";
    if [ -n "${GIT_PS1_SHOWCOLORHINTS-}" ]; then
        if [ $pcmode = yes ] || [ -n "${ZSH_VERSION-}" ]; then
            __git_ps1_colorize_gitstring;
        fi;
    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="$h$w$i$s$u";
    local gitstring="$c$b${f:+$z$f}${sparse}$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
}