50-prompt.sh

# Set prompt and title (for interactive shells only)
if [ "$(expr $- : '.*i')" -ne 0 ]; then

    # this works for sh and bash
    if [ -z "$ZSH_VERSION" ]; then
        # first get exit code of last command, and set colors
        PS1="\$(\
        EXIT=\"\$?\" ; \
        BLUE=\"\[\e[38;5;39m\]\" ; \
        RED=\"\[\e[31m\]\" ; \
        ORANGE=\"\[\e[38;5;208m\]\" ; \
        WHITE=\"\[\e[0m\]\" ; "
        # endchar
        #   use # for root and $ for non-root users
        #   use white for default color, and red if last exit code is non-zero
        PS1+="\
        endchar=\"\\$\${WHITE}\" ; \
        if [ \"\$EXIT\" -eq 0 ]; then
            endchar=\"\${WHITE}\$endchar\" ; \
        else \
            endchar=\"\${RED}\$endchar\" ; \
        fi ; "
        # current directory in blue(39)
        PS1+="\
        dir=\"\${BLUE}\w\${WHITE}\" ; "
        # check for $SSH_CONNECTION
        # in case $SSH_CONNECTION is lost, detect it manually via `who`
        _ssh_connection=${SSH_CONNECTION:-$__prompt_ssh_connection}
        if [ -z "$_ssh_connection" ]; then
            reIPv4='\(\(25[0-5]\|2[0-4][0-9]\|[01]\?[0-9]\{1,2\}\.\)\{3\}\(25[0-5]\|2[0-4][0-9]\|[01]\?[0-9]\{1,2\}\)\)'
            reIPv6='\(\([0-9a-fA-F]\{1,4\}:\)\{7,7\}[0-9a-fA-F]\{1,4\}\|\([0-9a-fA-F]\{1,4\}:\)\{1,7\}:\|\([0-9a-fA-F]\{1,4\}:\)\{1,6\}:[0-9a-fA-F]\{1,4\}\|\([0-9a-fA-F]\{1,4\}:\)\{1,5\}\(:[0-9a-fA-F]\{1,4\}\)\{1,2\}\|\([0-9a-fA-F]\{1,4\}:\)\{1,4\}\(:[0-9a-fA-F]\{1,4\}\)\{1,3\}\|\([0-9a-fA-F]\{1,4\}:\)\{1,3\}\(:[0-9a-fA-F]\{1,4\}\)\{1,4\}\|\([0-9a-fA-F]\{1,4\}:\)\{1,2\}\(:[0-9a-fA-F]\{1,4\}\)\{1,5\}\|[0-9a-fA-F]\{1,4\}:\(\(:[0-9a-fA-F]\{1,4\}\)\{1,6\}\)\|:\(\(:[0-9a-fA-F]\{1,4\}\)\{1,7\}\|:\)\|fe80:\(:[0-9a-fA-F]\{0,4\}\)\{0,4\}%[0-9a-zA-Z]\{1,\}\|::\(ffff\(:0\{1,4\}\)\{0,1\}:\)\{0,1\}\(\(25[0-5]\|\(2[0-4]\|1\{0,1\}[0-9]\)\{0,1\}[0-9]\)\.\)\{3,3\}\(25[0-5]\|\(2[0-4]\|1\{0,1\}[0-9]\)\{0,1\}[0-9]\)\|\([0-9a-fA-F]\{1,4\}:\)\{1,4\}:\(\(25[0-5]\|\(2[0-4]\|1\{0,1\}[0-9]\)\{0,1\}[0-9]\)\.\)\{3,3\}\(25[0-5]\|\(2[0-4]\|1\{0,1\}[0-9]\)\{0,1\}[0-9]\)\)'
            reHostname='\(\(\([a-zA-Z0-9]\|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9]\)\.\)*\([A-Za-z0-9]\|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9]\)\)'
            _ssh_connection="$(expr "$(who -m 2>/dev/null)" : '.* (\?\('$reIPv4'\|'$reIPv6'\|'$reHostname'\))\?' )"
        fi
        # export it so it works for programs such as tmux
        export __prompt_ssh_connection="$_ssh_connection"
        unset _ssh_connection
        # hide hostname and username except for ssh or su sessions
        #   use red for root and blue(39) for non-root users
        #   hostname in orange
        PS1+="\
        if [ -n \"\$__prompt_ssh_connection\" ]; then
            username=\"\${BLUE}\u\${WHITE}@\" ; \
            if [ \$UID = 0 ]; then
                username=\"\${RED}\u\${WHITE}@\" ; \
            fi ; \
            hostname=\"\${ORANGE}\H\${WHITE} \" ; \
        else
            if [ \"\$LOGNAME\" = \"\$(id -un)\" ]; then
                : ; \
            else
                username=\"\${BLUE}\u\${WHITE} \" ; \
                if [ \$UID = 0 ]; then
                    username=\"\${RED}\u\${WHITE} \" ; \
                fi ; \
            fi ; \
        fi ; "
        # set prompt, and additionally set window title for xterm
        if [ "${TERM:0:5}" = "xterm" ]; then
            PS1+="echo \"\[\e]2;\u@\H :: \w\a\]\$username\$hostname\$dir \$endchar \")"
        else
            PS1+="echo \"\$username\$hostname\$dir \$endchar\")"
        fi

    else
        # this works for zsh
        # endchar
        # use red if last command has non-zero exit
        # use # for root and $ for non-root users
        local _root_endch="%(?.#.%F{red}#%f)"
        local _other_endch="%(?.$.%F{red}$%f)"
        local _endchar="%(#.${_root_endch}.${_other_endch})"
        # current directory in blue(39)
        local _dir="%F{39}%~%f"
        # check for $SSH_CONNECTION
        # in case $SSH_CONNECTION is lost, detect it manually via `who`
        local _ssh_connection="${SSH_CONNECTION:-$__prompt_ssh_connection}"
        if [ -z "$_ssh_connection" ]; then
            local _reIPv4='([0-9]{1,3}\.){3}[0-9]+'
            local _reIPv6='(([0-9a-fA-F]+:)|:){2,}[0-9a-fA-F]+'
            local _reHostname='([.][^. ]+){2}'
            local -H MATCH MBEGIN MEND
            local -a match mbegin mend
            if [[ "$(who -m 2>/dev/null)" =~ "(\(?)($_reIPv4|$_reIPv6|$_reHostname)(\)?\$)" ]]; then
                _ssh_connection=${match[2]}
                # export it so it works for programs such as tmux
                export __prompt_ssh_connection="$_ssh_connection"
            fi
        fi
        # hide hostname and username except for ssh or su sessions
        if [ -n "$_ssh_connection" ]; then
            # use red for root and blue(39) for non-root users
            local _username="%F{%(#.red.39)}%n%f@"
            # hostname in orange
            local _hostname="%F{208}%m%f "
            # check if current session is in `su`
        elif [ "$LOGNAME" != "$(id -un)" ]; then
            # use red for root and blue(39) for non-root users
            local _username="%F{%(#.red.39)}%n%f "
        fi
        # set prompt
        PS1="${_username}${_hostname}${_dir} ${_endchar} "
        # additionally set window title for xterm
        __clr_default_title () {    # for xterm, set window title
            if [ "${TERM:0:5}" = "xterm" ]; then
                print -Pn "\e]2;%n\@%m :: %~\a"
            fi
        }
        __clr_default_title
        autoload -Uz add-zsh-hook
        add-zsh-hook chpwd __clr_default_title
    fi
fi