bash_prompt.sh

# Roland's Sophisticated Bash Prompt
#
#        Author: Roland Hopferwieser <develop -AT- int0x80.at>
#        Source: https://github.com/rhopfer/bash-prompt
# Last modified: February 21, 2024
#           vim: sw=4 ts=4 et
#
# Environment Variables
# ---------------------
# PROMPT_REPOS (boolean or string)
#     Show repository. Set it to 0 to disable it.
#     Set it to one or more of 'git', 'svn', 'hg' or 'bzr' to enable only these.
#
# PROMPT_HOST (boolean)
#     Show hostname in prompt. Normally shown on remote host. 
#
# PROMPT_USER (boolean)
#     Show username in prompt. Normally shown when root.
#
# PROMPT_IGNORE (string)
#     Colon separated string of sub-shells to ignore.
#
# PROMPT_DIRTRIM (integer)
#     Number of trailing path components shown (Default: 2)
#
# PROMPT_BASES (string)
#     Pathes that should be reduced to a name. The string has the form
#         name1=path1:name2=path2 ...
#
#     Example:
#         PATH_PROMPT="linux=/usr/src/linux"
#
# PROMPT_COLORS (string)
#     Define custom colors. The variable has the form
#         keyword1=color1:keyword2=color2 ...
#
#     Keywords:
#         host          the hostname
#         user          the username
#         root          user if the effective UID is 0
#         path          the path
#         jobs          the background jobs
#         at            the @ before hostname
#         display       the @ if X11 support available
#         symlink       if path is not the real path
#         sign          the prompt sign, $ for user, # for root
#         errsign       the sign if the recent command terminated with an error
#         errno         the error number (if not 0)
#         readonly      the trailing slash shown if the path is readonly
#         unsafe        the trailing slash shown if the path is world writeable
#         repos         the repository
#         changes       the sign for a repository with modifications
#         stash         the sign for a repository with stashes
#         term          the subshell
#
#     Colors:
#         A ANSI color sequence (see https://en.wikipedia.org/wiki/ANSI_escape_code#Colors)
#
#     Example:
#         PROMPT_COLORS="path=1;30:sign=1;33"
#
# PROMPT_FORCEBOL (boolean, string)
#     Force prompt to start on begin of line. On default it prints a gray '↵'.
#
# PROMPT_PROXY_LABEL (string)
#     Override label for proxy indicator. Defaults to 'proxy'.
#
# PROMPT_PLUGINS (array)
#     Allows to run custom functions. For every value 'myplugin' in array the function '__prompt_plugin_myplugin' is called.
#
#     Default plugins:
#         proxy    Add proxy indicator to environmen location if a proxy variable like 'http_proxy' is set.
#
#     Default plugins can be disabled by adding the plugin with '-' prefix to PROMPT_PLUGINS.
#
#     Example:
#         PROMPT_PLUGINS+=( myplugin -proxy )
#         __prompt_plugin_myplugin() {
#           # your custom code
#         }
#

if [[ $- != *i* ]]; then
    # Shell is non-interactive.  Be done now!
    return
fi

if [[ "$TERM" == dumb ]]; then
    # Make emacs / tramp happy.
    PS1='$ '
    return
fi

if [[ $(readlink -f /proc/self/fd/0) =~ /dev/tty ]]; then
    export __prompt_tty=1
fi

if [[ $(</proc/$$/environ tr '\0' '\n' | grep -E ^_=) == _=/usr/bin/newgrp ]]; then
    __prompt_newgrp="%$(groups | awk '{ print $1 }')"
fi

unset __prompt_environ
declare -A __prompt_environ

__prompt_default_plugins=( proxy )

__prompt_plugin_proxy() {
	local proxy
	for proxy in http_proxy https_proxy all_proxy HTTP_PROXY HTTPS_PROXY ALL_PROXY; do
		if [[ -n "${!proxy}" ]]; then
			__prompt_environ[proxy]=${PROMPT_PROXY_LABEL:-proxy}
			return
		fi
	done
	unset __prompt_environ[proxy]
}

function setprompt {
    local retval=$?
    local yes="(1|true|yes|always)"
    local no="(0|false|no|never)"
    local nocolor="\[\e[0m\]"
    local strike="\[\e[9m\]"
    local nostrike="\[\e[29m\]"

	__prompt_environ=()

    # Plugins
	local plugins=(${__prompt_default_plugins[@]}) plugin
    if [[ -n "$PROMPT_PLUGINS" ]]; then
		for plugin in "${PROMPT_PLUGINS[@]}"; do
			if [[ "${plugin:0:1}" == "-" ]]; then
				plugins=( "${plugins[@]/${plugin:1}}" )
			else
				plugins+=( "$plugin" )
			fi
		done
	fi
	plugins=( $(printf "%s\n" "${plugins[@]}" | sort -u) )
    if [[ -n "$plugins" ]]; then
        local plugin
        for plugin in "${plugins[@]}"; do
            local fun
            fun="__prompt_plugin_$plugin"
            if ! command -v $fun >/dev/null; then
                continue
            fi
            eval $fun
        done
    fi

    local ellipsis='…' stashsign='⇓'
    # TTYs do not display unicode characters
    if [[ -n $__prompt_tty ]]; then
        ellipsis='...'
        stashsign='&'
    fi

    # Force start of line
    local nlsign="\e[1;30m↵\e[0m"
    local col
    if [[ ! "$PROMPT_FORCEBOL" =~ $no || "$PROMPT_FORCEBOL" =~ "[" ]]; then
        if [[ "$PROMPT_FORCEBOL" =~ $yes && ! "$PROMPT_FORCEBOL" =~ "[" ]]; then
            nlsign=""
        elif [[ -n "$PROMPT_FORCEBOL" ]]; then
            nlsign=$PROMPT_FORCEBOL
        fi
        # read cursor position
        read -s -dR -p $'\e[6n' col
        col=${col#*;}
        if [[ $col -gt 1 ]]; then
            echo -e $nlsign
        fi
    fi

    declare -A colors
    if [[ $(tput colors 2> /dev/null) -gt 8 ]]; then
        # 256 color terminal
        colors[host]="0;38;5;33"
        colors[user]="0;38;5;33"
        colors[root]="1;38;5;160"
        colors[path]="0;1"
        colors[jobs]="0;38;5;136"
        colors[at]="0;38;5;245"
        colors[display]="0;38;5;40"
        colors[symlink]="1;38;5;245"
        colors[sign]="0;38;5;40"
        colors[errsign]="0;38;5;160"
        colors[errno]="0;38;5;245"
        colors[readonly]="1;38;5;160"
        colors[unsafe]="1;38;5;136"
        colors[changes]="0"
        colors[stash]="0"
        colors[repos]="0;38;5;37"
        colors[term]="0;38;5;125"
        colors[base]="4"
    else
        # 16 color terminal
        colors[host]="0;34"       # cyan
        colors[user]="1;34"       # bright blue
        colors[root]="1;31"       # bright red
        colors[path]="0;1"        # default
        colors[jobs]="0;33"       # yellow
        colors[at]="1;30"         # gray
        colors[display]="0;32"    # green
        colors[symlink]="1;30"    # gray
        colors[sign]="0;32"       # green
        colors[errsign]="0;31"    # red
        colors[errno]="1;30"      # gray
        colors[readonly]="0;31"   # red
        colors[unsafe]="1;33"     # bright yellow
        colors[changes]="0"       # bold
        colors[stash]="0"         # bold
        colors[repos]="1;36"      # bright blue
        colors[term]="0;35"       # magenta
        colors[base]="4"          # underlined
    fi

    # Load custom colors
    declare -A custom_colors
    if [[ -n "$PROMPT_COLORS" ]]; then
        while read k v; do
            custom_colors[$k]=$v
        done < <(<<<"$PROMPT_COLORS" awk -F= '{print $1,$2}' RS=':|\n')
    fi
    for c in "${!colors[@]}"; do
        if [[ -n "${custom_colors[$c]}" ]]; then
            colors[$c]="${custom_colors[$c]}"
        fi
        colors[$c]="\[\e[${colors[$c]}m\]"
    done

    # Determine information from parent processes
    local ppid=$PPID
    local user_switched=0
    local subsh=
    local remote=0
    local shlvl=0
    if [[ $ppid -eq 0 && -r /proc/self/stat ]]; then
        # for chroot using unshare like arch-chroot does
        local stat=$(</proc/self/stat)
        ppid=$(echo $stat | awk '{print $4; }')
    fi
    if [[ -f /.dockerenv ]]; then
        subsh=docker
    fi
    while [[ $ppid -ne 1 ]]; do
        [ -r /proc/$ppid/comm ] || break
        local comm=$(</proc/$ppid/comm)

        # Check for user switching
        if [[ $remote -eq 0 && "$comm" =~ bash|su ]]; then
            local uid=$(awk '/Uid:/ { print $2; }' /proc/$ppid/status)
            if [[ $uid -ne $EUID ]]; then
                user_switched=1
            fi
        fi

        if [[ -n "$__prompt_newgrp" ]]; then
            subsh="$__prompt_newgrp"
        elif [[ ${EUID} == 0 && "$(stat -c %d:%i /)" != "$(stat -c %d:%i /proc/1/root/.)" ]]; then
            subsh=chroot
        fi

        if [[ -z "$subsh" ]]; then
            if [[ "$comm" == bash && $user_switched -eq 0 ]]; then
                shlvl=$((shlvl+1))
            elif [[ $shlvl -gt 0 && ! "$PROMPT_IGNORE" =~ bash ]]; then
                subsh=bash
            elif [[ "$comm" =~ script|screen|tmux|vcsh|pipenv && ! "$PROMPT_IGNORE" =~ "$comm" ]]; then
                subsh=$comm
            fi
        fi
        if [[ "$comm" =~ ssh ]]; then
            remote=1
        fi

        ppid=`awk '{ print $4 }' /proc/$ppid/stat`
    done

    # Hostname
    local host=""
    if [[ ! "$PROMPT_HOST" =~ $no ]]; then
        if [[ $remote -eq 1 || -n "$PROMPT_HOST" ]]; then
            host=`hostname`
                        host="${host%%.*}"
        fi
    fi
    if [[ -n "$host" ]]; then
        if [[ -n "$DISPLAY" ]]; then
            # Green '@' with X11 support
            host="${colors[display]}@${colors[host]}${host}${nocolor}"
        else
            host="${colors[at]}@${colors[host]}${host}${nocolor}"
        fi
    fi

    # Username
    local user=""
    if [[ "$PROMPT_USER" =~ $yes || ${EUID} -eq 0 || $user_switched -eq 1 ]]; then
        user="\u"
    elif [[ "$PROMPT_USER" =~ $no ]]; then
        : # do nothing
    fi
    if [[ -n "$user" ]]; then
        if [[ ${EUID} -eq 0 ]] ; then
            user="${colors[root]}${user}"
        else
            user="${colors[user]}${user}"
        fi
        if [[ -z "$host" ]]; then
            user="${user}"
        fi
    fi

    # Path
    local path="$PWD"
    local pwd base basebath root skip
    # Resolve relative PWD (happend if inside deleted directory)
    while [[ -n $path ]]; do
        local dir=${path##*/}
        if [[ "$dir" == '..' ]]; then
            let skip=$skip+1
        elif [[ "$dir" == '.' ]]; then
            :
        elif [[ $skip -gt 0 ]]; then
            let skip=$skip-1
        else
            pwd="/${dir}${pwd}"
        fi
        path=${path%/*}
    done
    path="$pwd"

    local home="${HOME%%/}"
    while read basepath name; do
        basepath="${basepath/#\~/$home}"
        basepath="${basepath%/}"
        if [[ -n "$basepath" && "$path" == "$basepath"* ]]; then
            path=${path/#$basepath/}
            root="${basepath%/}"
            base="${colors[base]}${name}${nocolor}"
            break
        fi
    done < <(<<<$PROMPT_BASES awk -F= '{print $2,$1}' RS=':|\n')
    if [[ -z "$base" && "$path" == "$home"* ]]; then
        path="${path/$home/}"
        base="${colors[path]}~${nocolor}"
    fi

    local realpath=$( readlink -f . )
    local dirs symlink deleted
    local dirtrim=${PROMPT_DIRTRIM:-2}
    if [[ "$realpath" == '' ]]; then
        deleted=1
    elif [[ "$realpath" != "$pwd" ]]; then
        symlink=1
    fi

    while [[ -n "$path" ]]; do
        local elem="${path##*/}"
        local count=$((count + 1))
        dirs="${elem}/${dirs}"

        if [[ $deleted -eq 1 ]]; then
            realpath=$( readlink -f "${root}${path}" )
            if [[ "$realpath" != '' ]]; then
                dirs="${strike}$dirs"
                deleted=0
                [[ "$realpath" != "${root}${path}" ]] && symlink=1
            fi
        elif [[ $symlink -eq 1 && -L "${root}${path}" ]]; then
            dirs="${colors[symlink]}$dirs"
            symlink=0
        fi
        path="${path%/*}"
        if [[ $dirtrim -gt 0 && $count -eq $dirtrim ]]; then
            break
        fi
    done
    [[ -n $dirs && $deleted -eq 1 ]] && dirs="${strike}$dirs"
    [[ -n $dirs && $symlink -eq 1 ]] && dirs="${colors[symlink]}$dirs"
    if [[ -n $path ]]; then
        dirs="${ellipsis}/$dirs"
    elif [[ ( -z $base ) ]]; then
        dirs="/$dirs"
    fi
    [[ ( -n "$base" && -n "$dirs" ) ]] && dirs="/$dirs"
    path="${dirs%/}"
    path="${base}${colors[path]}${path}"
    [[ -n $deleted ]] && path="${path}${nostrike}"

    # Show extra '/' if path is not or world writeable
    if [[ ! -w "$pwd" ]]; then
        path="${path%%/}${colors[readonly]}/"
    elif [[ ! -k "$pwd" && $((`stat -Lc "0%a" "$pwd"` & 0002)) != 0 ]]; then
        path="${path%%/}${colors[unsafe]}/"
    fi
    if [[ -n "${user}" || -n "${host}" ]]; then
        # separate path from user/host
        path=" $path"
    fi
    path="${path}${nocolor}"

    # Close sign
    local sign="\\\$"
    if [[ $retval -eq 0 ]]; then
        sign="${colors[sign]}${sign}"
    else
        sign="${colors[errno]}${retval}${colors[errsign]}${sign}"
    fi
    sign="${sign}${nocolor}"

    # Jobs
    local jobs=""
    if [ $(jobs -p | wc -l) -gt 0 ]; then
        jobs="${colors[jobs]}[\j]${nocolor}"
    fi

    # Repositories
    local repos=""
    local git svn hg bzr owncloud nextcloud
    if [[ -n "$PROMPT_REPOS" && ! $PROMPT_REPOS =~ $yes ]]; then
        [[ $PROMPT_REPOS =~ $no || ! $PROMPT_REPOS == *git* ]] && git=0
        [[ $PROMPT_REPOS =~ $no || ! $PROMPT_REPOS == *svn* ]] && svn=0
        [[ $PROMPT_REPOS =~ $no || ! $PROMPT_REPOS == *hg* ]] && hg=0
        [[ $PROMPT_REPOS =~ $no || ! $PROMPT_REPOS == *bzr* ]] && bzr=0
        [[ $PROMPT_REPOS =~ $no || ! $PROMPT_REPOS == *owncloud* ]] && owncloud=0
        [[ $PROMPT_REPOS =~ $no || ! $PROMPT_REPOS == *nextcloud* ]] && nextcloud=0
    fi
    local dir=$( readlink -f "$pwd" )
    [[ -n "$GIT_DIR" ]] && git=1
    while [[ -n "$dir" ]]; do
        [[ -z "$git" && -d "$dir/.git" ]] && git=1
        [[ -z "$svn" && -d "$dir/.svn" ]] && svn=1
        [[ -z "$hg" && -d "$dir/.hg" ]] && hg=1
        [[ -z "$bzr" && -d "$dir/.bzr" ]] && bzr=1
        mountpoint -q -- "$dir" && break
        dir="${dir%/*}"
    done
    if [[ $git -eq 1 && -x /usr/bin/git ]]; then
        local git_info=$(/usr/bin/git describe --tags --exact-match HEAD 2>/dev/null)
        if [[ -z "$git_info" ]]; then
            git_info=$(/usr/bin/git symbolic-ref -q --short HEAD)
        fi
        if [[ -z "$git_info" ]]; then
            git_info=$(/usr/bin/git rev-parse -q --short HEAD)
        fi
        if [[ -n "${git_info}" ]]; then
            local git_stash=$(git stash list | wc -l)
            if [[ $git_stash -gt 0 ]]; then
                git_info="${git_info}${colors[stash]}${stashsign}${colors[repos]}"
            fi
            if [[ $(/usr/bin/git status -s 2>/dev/null | grep -E '^ ?([MARD]+) ') ]]; then
                git_info="${git_info}${colors[changes]}*${colors[repos]}"
            fi
            repos="${colors[repos]}{${git_info}}"
        fi
    fi
    if [[ $svn -eq 1 && -x /usr/bin/svnversion ]]; then
        local svn_stat=$(/usr/bin/svnversion 2>/dev/null)
        local svn_rev=$(echo $svn_stat | sed -nre 's/([0-9]+:?[0-9]+).*/\1/p')
        if [[ -n $svn_rev ]]; then
            if [[ $svn_stat =~ M$ ]]; then
                svn_rev="${svn_rev}${colors[changes]}*${colors[repos]}"
            fi
            repos="${repos}${colors[repos]}{r${svn_rev}}"
        fi
    fi
    if [[ $hg -eq 1 && -x /usr/bin/hg ]]; then
        local hg_info=$(/usr/bin/hg branch 2>/dev/null)
        if [[ -n ${hg_info} ]]; then
            if [[ $(/usr/bin/hg status -q 2>/dev/null | grep -E '^[MAR]+ ') ]]; then
                hg_info="${hg_info}${colors[changes]}*${colors[repos]}"
            fi
            repos="${repos}${colors[repos]}{${hg_info}}"
        fi
    fi
    if [[ $bzr -eq 1 && -x /usr/bin/bzr ]]; then
        local bzr_info=$(/usr/bin/bzr version-info --check-clean --custom --template='{branch_nick} {revno} {clean}' 2> /dev/null)
        if [[ -n ${bzr_info} ]]; then
            local bzr_branch bzr_rev bzr_clean
            read bzr_branch bzr_rev bzr_clean <<<"$bzr_info"
            bzr_info="$bzr_branch/$bzr_rev"
            if [[ $bzr_clean -eq 0 ]]; then
                bzr_info="${bzr_info}${colors[changes]}*${colors[repos]}"
            fi
            repos="${repos}${colors[repos]}{${bzr_info}}"
        fi
    fi

    # Owncloud
    local dir=$( readlink -f "$pwd" )
    local cloud_info
    while [[ -n "$dir" ]]; do
        if [[ -e "$dir/.owncloudsync.log" ]]; then
            grep -q "localPath=$dir" "$HOME/.local/share/data/ownCloud/owncloud.cfg" 2> /dev/null
            (( $? != 0 )) && break
            if pidof owncloud > /dev/null; then
                cloud_info="owncloud"
            else
                cloud_info="${strike}owncloud${nostrike}"
            fi
            repos="${repos}${colors[repos]}{${cloud_info}}"
            break
        fi
        mountpoint -q -- "$dir" && break
        dir="${dir%/*}"
    done

    # Subshell
    if [[ "$subsh" == bash ]]; then
        subsh="$shlvl"
    elif [[ "$subsh" == vcsh && -n "$VCSH_REPO_NAME" ]]; then
        subsh="$subsh:$VCSH_REPO_NAME"
    elif [[ "$subsh" == screen && -n $WINDOW ]]; then
        subsh=$subsh:$WINDOW
    fi

    if [[ -n "${__prompt_environ[*]}" ]]; then
        # local envs=( $(paste -d: <(printf "%s\n" "${!__prompt_environ[@]}") <(printf "%q\n" "${__prompt_environ[@]}")) )
        local envs=( $(printf "%q\n" "${__prompt_environ[@]}") )
        subsh=$(IFS=","; echo "${envs[*]}")
    fi
    if [[ -n "$subsh" ]]; then
        subsh="${colors[term]}(${subsh})${nocolor} "
    fi

    PS1="${nocolor}${subsh}${user}${host}${path}${repos}${jobs} ${sign} "
}

PROMPT_COMMAND=setprompt