Highly configurable prompt builder for Bash and ZSH written in Go. It's inspired by the Oh My ZSH Bullet Train theme.

Works well on Linux (Terminator, Konsole, Gnome Terminal) and Mac (Terminal, iTerm). It has no other dependencies than Go and its standard libraries.

• Installation
• Usage
• Configuration
  • Colors
  • Formatting
  • Train variables
  • Cars variables
    • Custom car
    • Dir car
    • ExecTime car
    • Git car
    • Hostname car
    • Os car
    • PyVirtEnv car
    • Sign car
    • Status car
    • Time car
• Prompt forwarding
• Author
• License

On Arch Linux:

yaourt -S gbt

On CentOS/RHEL:

cat > /etc/yum.repos.d/gbt.repo <<END
[gbt]
name=GBT YUM repo
baseurl=https://packagecloud.io/jtyr/gbt/el/7/\$basearch
gpgkey=https://packagecloud.io/jtyr/gbt/gpgkey/jtyr-gbt-4C6E79EFF45439B6.pub.gpg
gpgcheck=1
END
yum install gbt

On Ubuntu/Debian:

curl -L https://packagecloud.io/jtyr/gbt/gpgkey | apt-key add -
echo 'deb https://packagecloud.io/jtyr/gbt/ubuntu/ xenial main' > /etc/apt/sources.list.d/gbt.list
apt-get update
apt-get install gbt

On Mac via Homebrew:

brew tap jtyr/repo
brew install gbt

From source code:

go get -u github.com/jtyr/gbt
go build -o ~/gbt github.com/jtyr/gbt

GBT can be activated by calling it from the shell prompt variable:

# For Bash
PS1='$(gbt $?)'
# For ZSH
PROMPT='$(gbt $?)'

In order to display all colors correctly, the terminal should use 256 color scheme:

export TERM="xterm-256color"

In order to display all characters of the prompt correctly, the shell should support UTF-8 and Nerd (or at least Powerline) fonts should be installed and set in the terminal application.

### Test the Status car
false
true
### Test the Dir car
cd /
cd /usr/share/doc/sudo
# Display only last 3 elements of the path
export GBT_CAR_DIR_DEPTH="3"
# Display full path
export GBT_CAR_DIR_DEPTH="9999"
# Show only last element of the path
unset GBT_CAR_DIR_DEPTH
cd ~
### Test Time car
# Add the Time car into the train
export GBT_CARS="Status, Os, Time, Hostname, Dir, Sign"
# Set 12h format
export GBT_CAR_TIME_TIME_FORMAT="03:04:05 PM"
# Change background color of the all car
export GBT_CAR_TIME_BG="yellow"
# Change color of Date part
export GBT_CAR_TIME_DATE_FG="black"
# Reset the color of the Date part
unset GBT_CAR_TIME_DATE_FG
# Reset the background color of all Time car
unset GBT_CAR_TIME_BG
# Remove the Date part from the car
export GBT_CAR_TIME_FORMAT=" {{ Time }} "
# Reset the format of the car
unset GBT_CAR_TIME_FORMAT
# Reset the original train
unset GBT_CARS
### Themes
# Load theme
source /usr/share/gbt/themes/square_brackets_multiline

The prompt (train) is assembled from several elements (cars). The look and behavior of whole train as well as each car can be influenced by a set of environment variables. Majority of the

The value of all _BG and _FG variables defines the background and foreground color of the particular element. The value of the color can be specified in 3 ways:

Only a limited number of named colors is supported:

• black
• red
• green
• yellow
• blue
• magenta
• cyan
• light_gray
• dark_gray
• light_red
• light_green
• light_yellow
• light_blue
• light_magenta
• light_cyan
• white
• default (default color of the terminal)

Examples:

# Set the background color of the `Dir` car to red
export GBT_CAR_DIR_BG="red"
# Set the foreground color of the `Dir` car to white
export GBT_CAR_DIR_FG="white"

Color can also by expressed by a single number in the range from 0 to 255. The color of each number in that range is visible in the 256-color lookup table on Wikipedia. The named colors described above are the first 16 numbers from the lookup table.

Examples:

# Set the background color of the `Dir` car to red
export GBT_CAR_DIR_BG="1"
# Set the foreground color of the `Dir` car to white
export GBT_CAR_DIR_FG="15"

Arbitrary color can be expressed in the form of RGB triplet.

Examples:

# Set the background color of the `Dir` car to red
export GBT_CAR_DIR_BG="170;0;0"
# Set the foreground color of the `Dir` car to white
export GBT_CAR_DIR_FG="255;255;255"

Formatting is done via _FM variables. The possible values are:

• bold

  Makes the text bold. Not all font characters have variant for bold formatting.

• underline

  Makes the text underlined.

• blink

  Makes the text to blink.

• none

  No formatting applied.

  Example:

  # Set the directory name to be bold
  export GBT_CAR_DIR_FM="bold"

• GBT_CARS="Status, Os, Hostname, Dir, Git, Sign"

  List of cars used in the train.

  To add a new car into the train, the whole variable must be redefined. For example in order to add the Time car into the default set of cars between the Os and Hostname car, the variable should look like this:

  export GBT_CARS="Status, Os, Time, Hostname, Dir, Git, Sign"

• GBT_RCARS="Time"

  The same like GBT_CARS but for the right hand side prompt.

  # Add the Custom car into the right hand site car to have the separator visible
  export GBT_RCARS="Custom, Time"
  # Make the Custom car to be invisible (zero length text)
  export GBT_CAR_CUSTOM_BG="default"
  export GBT_CAR_CUSTOM_FORMAT=""
  # Show only time
  export GBT_CAR_TIME_FORMAT=" {{ Time }} "
  # Set the right hand side prompt (ZSH only)
  export RPROMPT='$(gbt -right)'

• GBT_SEPARATOR=""

  Character used to separate cars in the train.

• GBT_RSEPARATOR=""

  The same like GBT_SEPARATOR but for the right hand side prompt.

• GBT_CAR_BG

  Background color inherited by the top background color variable of every car. That allows to set the background color of all cars via single variable.

• GBT_CAR_FG

  Foreground color inherited by the top foreground color variable of every car. That allows to set the foreground color of all cars via single variable.

• GBT_CAR_FM

  Formatting inherited by the top formatting variable of every car. That allows to set the formatting of all cars via single variable.

• GBT_BEGINNING_BG="default"

  Background color of the text shown at the beginning of the train.

• GBT_BEGINNING_FG="default"

  Foreground color of the text shown at the beginning of the train.

• GBT_BEGINNING_FM="none"

  Formatting of the text shown at the beginning of the train.

• GBT_BEGINNING_TEXT=""

  Text shown at the beginning of the train.

• GBT_SHELL

  Indicates which shell is used. The value can be either zsh or bash. By default, the value is extracted from the $SHELL environment variable. Set this variable to bash if your default shell is ZSH but you want to test GBT in Bash:

  export GBT_SHELL="bash"
  bash

• GBT_DEBUG="0"

  Shows more verbose output if some of the car modules cannot be imported.

The main purpose of this car is to provide the possibility to create car with custom text.

• GBT_CAR_CUSTOM_BG="yellow"

  Background color of the car.

• GBT_CAR_CUSTOM_FG="default"

  Foreground color of the car.

• GBT_CAR_CUSTOM_FM="none"

  Formatting of the car.

• GBT_CAR_CUSTOM_FORMAT=" {{ Text }} "

  Format of the car.

• GBT_CAR_CUSTOM_TEXT_BG

  Background color of the {{ Text }} element.

• GBT_CAR_CUSTOM_TEXT_FG

  Foreground color of the {{ Text }} element.

• GBT_CAR_CUSTOM_TEXT_FM

  Formatting of the {{ Text }} element.

• GBT_CAR_CUSTOM_TEXT_TEXT="?"

  Text content of the {{ Text }} element.

• GBT_CAR_CUSTOM_TEXT_CMD

  The {{ Text }} element will be replaced by standard output of the command specified in this variable. Content of the GBT_CAR_CUSTOM_TEXT_TEXT variable takes precedence over this variable.

  # Show 1 minute loadavg as the content of the Text element
  export GBT_CAR_CUSTOM_CMD="uptime | sed --e 's/.*load average: //' -e 's/,.*//'"

• GBT_CAR_CUSTOM_DISPLAY="1"

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_CUSTOM_DISPLAY_CMD

  Command which gets executed in order to evaluate whether the car should be displayed or not. Content of the GBT_CAR_CUSTOM_DISPLAY variable takes precedence over this variable.

  # Show percentage of used disk space of the root partition
  export GBT_CAR_CUSTOM_TEXT_CMD="df -h --output=pcent / | tail -n1 | sed -re 's/\s//g' -e 's/%/%%/'"
  # Display the car only if the percentage is above 90%
  export GBT_CAR_CUSTOM_DISPLAY_CMD="[[ $(df -h --output=pcent / | tail -n1 | sed -re 's/\s//g' -e 's/%//') -gt 70 ]] && echo YES"

• GBT_CAR_CUSTOM_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_CUSTOM_SEP

  Custom separator string for this car.

Multiple Custom cars can be used in the GBT_CARS variable. Just add some identifier behind the car name. To set properties of the new car, just add the same identifier into the environment variable:

# Adding Custom and Custo1 car
export GBT_CARS="Status, Os, Custom, Custom1, Hostname, Dir, Git, Sign"
# The text of the default Custom car
export GBT_CAR_CUSTOM_TEXT_TEXT="default"
# The text of the Custom1 car
export GBT_CAR_CUSTOM1_TEXT_TEXT="1"
# Set different background color for the Custom1 car
export GBT_CAR_CUSTOM1_BG="magenta"

Car that displays current directory name.

• GBT_CAR_DIR_BG="blue"

  Background color of the car.

• GBT_CAR_DIR_FG="light_gray"

  Foreground color of the car.

• GBT_CAR_DIR_FM="none"

  Formatting of the car.

• GBT_CAR_DIR_FORMAT=" {{ Dir }} "

  Format of the car.

• GBT_CAR_DIR_DIR_BG

  Background color of the {{ Dir }} element.

• GBT_CAR_DIR_DIR_FG

  Foreground color of the {{ Dir }} element.

• GBT_CAR_DIR_DIR_FM

  Formatting of the {{ Dir }} element.

• GBT_CAR_DIR_DIR_TEXT

  Text content of the {{ Dir }} element. The directory name.

• GBT_CAR_DIR_DIRSEP

  OS-default character used to separate directories.

• GBT_CAR_DIR_HOMESIGN="~"

  Character which represents the user's home directory. If set to empty string, full home directory path is used instead.

• GBT_CAR_DIR_DEPTH="1"

  Number of directories to show.

• GBT_CAR_DIR_DISPLAY="1"

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_DIR_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_DIR_SEP

  Custom separator string for this car.

Car that displays how long each shell command run.

• GBT_CAR_EXECTIME_BG="light_gray"

  Background color of the car.

• GBT_CAR_EXECTIME_FG="black"

  Foreground color of the car.

• GBT_CAR_EXECTIME_FM="none"

  Formatting of the car.

• GBT_CAR_EXECTIME_FORMAT=" {{ Time }} "

  Format of the car.

• GBT_CAR_EXECTIME_TIME_BG

  Background color of the {{ Time }} element.

• GBT_CAR_EXECTIME_TIME_FG

  Foreground color of the {{ Time }} element.

• GBT_CAR_EXECTIME_TIME_FM

  Formatting of the {{ Time }} element.

• GBT_CAR_EXECTIME_TIME_TEXT

  Text content of the {{ Time }} element. The execution time.

• GBT_CAR_EXECTIME_DIRSEP

  OS-default character used to separate directories.

• GBT_CAR_EXECTIME_PRECISION="0"

  Sub-second precision to show.

• GBT_CAR_EXECTIME_SECS

  The number of seconds the command run in shell. This variable is defined in the source file as shown bellow.

• GBT_CAR_EXECTIME_BELL="0"

  Sound console bell if the executed command exceeds specified number of seconds. Value set to 0 disables the bell (default).

• GBT_CAR_EXECTIME_DISPLAY="1"

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_EXECTIME_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_EXECTIME_SEP

  Custom separator string for this car.

In order to allow this car to calculate the execution time, the following must be loaded in the shell:

# For Bash
source /usr/share/gbt/sources/exec_time/bash
# For ZSH
source /usr/share/gbt/sources/exec_time/zsh

Car that displays information about a local Git repository. This car is displayed only if the current directory is a Git repository.

• GBT_CAR_GIT_BG="light_gray"

  Background color of the car.

• GBT_CAR_GIT_FG="black"

  Foreground color of the car.

• GBT_CAR_GIT_FM="none"

  Formatting of the car.

• GBT_CAR_GIT_FORMAT=" {{ Icon }} {{ Head }} {{ Status }}{{ Ahead }}{{ Behind }} "

  Format of the car.

• GBT_CAR_GIT_ICON_BG

  Background color of the {{ Icon }} element.

• GBT_CAR_GIT_ICON_FG

  Foreground color of the {{ Icon }} element.

• GBT_CAR_GIT_ICON_FM

  Formatting of the {{ Icon }} element.

• GBT_CAR_GIT_ICON_TEXT=""

  Text content of the {{ Icon }} element.

• GBT_CAR_GIT_HEAD_BG

  Background color of the {{ Head }} element.

• GBT_CAR_GIT_HEAD_FG

  Foreground color of the {{ Head }} element.

• GBT_CAR_GIT_HEAD_FM

  Formatting of the {{ Head }} element.

• GBT_CAR_GIT_HEAD_TEXT

  Text content of the {{ Head }} element. The branch or tag name or the commit ID.

• GBT_CAR_GIT_STATUS_BG

  Background color of the {{ Status }} element.

• GBT_CAR_GIT_STATUS_FG

  Foreground color of the {{ Status }} element.

• GBT_CAR_GIT_STATUS_FM

  Formatting of the {{ Status }} element.

• GBT_CAR_GIT_STATUS_FORMAT

  Format of the {{ Status }} element. The content is either {{ Dirty }} or {{ Clean }} depending on the state of the local Git repository.

• GBT_CAR_GIT_DIRTY_BG

  Background color of the {{ Dirty }} element.

• GBT_CAR_GIT_DIRTY_FG="red"

  Foreground color of the {{ Dirty }} element.

• GBT_CAR_GIT_DIRTY_FM

  Formatting of the {{ Dirty }} element.

• GBT_CAR_GIT_DIRTY_TEXT="✘"

  Text content of the {{ Dirty }} element.

• GBT_CAR_GIT_CLEAN_BG

  Background color of the {{ Clean }} element.

• GBT_CAR_GIT_CLEAN_FG="green"

  Foreground color of the {{ Clean }} element.

• GBT_CAR_GIT_CLEAN_FM

  Formatting of the {{ Clean }} element.

• GBT_CAR_GIT_CLEAN_TEXT="✔"

  Text content of the {{ Clean }} element.

• GBT_CAR_GIT_AHEAD_BG

  Background color of the {{ Ahead }} element.

• GBT_CAR_GIT_AHEAD_FG

  Foreground color of the {{ Ahead }} element.

• GBT_CAR_GIT_AHEAD_FM

  Formatting of the {{ Ahead }} element.

• GBT_CAR_GIT_AHEAD_TEXT=" ⬆"

  Text content of the {{ Ahead }} element.

• GBT_CAR_GIT_BEHIND_BG

  Background color of the {{ Behind }} element.

• GBT_CAR_GIT_BEHIND_FG

  Foreground color of the {{ Behind }} element.

• GBT_CAR_GIT_BEHIND_FM

  Formatting of the {{ Behind }} element.

• GBT_CAR_GIT_BEHIND_TEXT=" ⬇"

  Text content of the {{ Behind }} element.

• GBT_CAR_GIT_DISPLAY

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_GIT_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_GIT_SEP

  Custom separator string for this car.

Car that displays username of the currently logged user and the hostname of the local machine.

• GBT_CAR_HOSTNAME_BG="dark_gray"

  Background color of the car.

• GBT_CAR_HOSTNAME_FG="252"

  Foreground color of the car.

• GBT_CAR_HOSTNAME_FM="none"

  Formatting of the car.

• GBT_CAR_HOSTNAME_FORMAT=" {{ UserHost }} "

  Format of the car.

• GBT_CAR_HOSTNAME_USERHOST_BG

  Background color of the {{ UserHost }} element.

• GBT_CAR_HOSTNAME_USERHOST_FG

  Foreground color of the {{ UserHost }} element.

• GBT_CAR_HOSTNAME_USERHOST_FM

  Formatting of the {{ UserHost }} element.

• GBT_CAR_HOSTNAME_USERHOST_FORMAT

  Format of the {{ UserHost }} element. The value is either {{ Admin }}@{{ Host }} if the user is root or {{ User }}@{{ Host }} if the user is a normal user.

• GBT_CAR_HOSTNAME_ADMIN_BG

  Background color of the {{ Admin }} element.

• GBT_CAR_HOSTNAME_ADMIN_FG

  Foreground color of the {{ Admin }} element.

• GBT_CAR_HOSTNAME_ADMIN_FM

  Formatting of the {{ Admin }} element.

• GBT_CAR_HOSTNAME_ADMIN_TEXT

  Text content of the {{ Admin }} element. The user name.

• GBT_CAR_HOSTNAME_USER_BG

  Background color of the {{ User }} element.

• GBT_CAR_HOSTNAME_USER_FG

  Foreground color of the {{ User }} element.

• GBT_CAR_HOSTNAME_USER_FM

  Formatting of the {{ User }} element.

• GBT_CAR_HOSTNAME_USER_TEXT

  Text content of the {{ User }} element. The user name.

• GBT_CAR_HOSTNAME_HOST_BG

  Background color of the {{ Host }} element.

• GBT_CAR_HOSTNAME_HOST_FG

  Foreground color of the {{ Host }} element.

• GBT_CAR_HOSTNAME_HOST_FM

  Formatting of the {{ Host }} element.

• GBT_CAR_HOSTNAME_HOST_TEXT

  Text content of the {{ Host }} element. The host name.

• GBT_CAR_HOSTNAME_DISPLAY="1"

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_HOSTNAME_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_HOSTNAME_SEP

  Custom separator string for this car.

Car that displays icon of the operating system.

• GBT_CAR_OS_BG="235"

  Background color of the car.

• GBT_CAR_OS_FG="white"

  Foreground color of the car.

• GBT_CAR_OS_FM="none"

  Formatting of the car.

• GBT_CAR_OS_FORMAT=" {{ Symbol }} "

  Format of the car.

• GBT_CAR_OS_SYMBOL_BG

  Background color of the {{ Symbol }} element.

• GBT_CAR_OS_SYMBOL_FG

  Foreground color of the {{ Symbol }} element.

• GBT_CAR_OS_SYMBOL_FM

  Formatting of the {{ Symbol }} element.

• GBT_CAR_OS_SYMBOL_TEXT

  Text content of the {{ Symbol }} element.

• GBT_CAR_OS_NAME

  The name of the symbol to display. Default value is selected by the system the shell runs at. Possible names and their symbols are:

  • amzn 
  • android 
  • arch 
  • archarm 
  • centos 
  • cloud 
  • coreos 
  • darwin 
  • debian 
  • docker 
  • elementary 
  • fedora 
  • freebsd 
  • gentoo 
  • linux 
  • linuxmint 
  • mageia 
  • mandriva 
  • opensuse 
  • raspbian 
  • redhat 
  • sabayon 
  • slackware 
  • ubuntu 
  • windows 

  Example:

  export GBT_CAR_OS_NAME="arch"

• GBT_CAR_OS_DISPLAY="1"

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_OS_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_OS_SEP

  Custom separator string for this car.

Car that displays Python Virtual Environment name. This car is displayed only if the Python Virtual Environment is activated. The activation script usually prepends the shell prompt by the Virtual Environment name by default. In order to disable it, the following environment variable must be set:

export VIRTUAL_ENV_DISABLE_PROMPT="1"

Variables used by the car:

• GBT_CAR_PYVIRTENV_BG="222"

  Background color of the car.

• GBT_CAR_PYVIRTENV_FG="black"

  Foreground color of the car.

• GBT_CAR_PYVIRTENV_FM="none"

  Formatting of the car.

• GBT_CAR_PYVIRTENV_FORMAT=" {{ Icon }} {{ Name }} "

  Format of the car.

• GBT_CAR_PYVIRTENV_ICON_BG

  Background color of the {{ Icon }} element.

• GBT_CAR_PYVIRTENV_ICON_FG

  Foreground color of the {{ Icon }} element.

• GBT_CAR_PYVIRTENV_ICON_FM

  Formatting of the {{ Icon }} element.

• GBT_CAR_PYVIRTENV_ICON_TEXT

  Text content of the {{ Icon }} element.

• GBT_CAR_PYVIRTENV_NAME_BG

  Background color of the {{ Name }} element.

• GBT_CAR_PYVIRTENV_NAME_FG="33"

  Foreground color of the {{ NAME }} element.

• GBT_CAR_PYVIRTENV_NAME_FM

  Formatting of the {{ Name }} element.

• GBT_CAR_PYVIRTENV_NAME_TEXT

  The name of the Python Virtual Environment deducted from the VIRTUAL_ENV environment variable.

• GBT_CAR_PYVIRTENV_DISPLAY

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_PYVIRTENV_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_PYVIRTENV_SEP

  Custom separator string for this car.

Car that displays prompt character for the admin and user at the end of the train.

• GBT_CAR_SIGN_BG="default"

  Background color of the car.

• GBT_CAR_SIGN_FG="default"

  Foreground color of the car.

• GBT_CAR_SIGN_FM="none"

  Formatting of the car.

• GBT_CAR_SIGN_FORMAT=" {{ Symbol }} "

  Format of the car.

• GBT_CAR_SIGN_SYMBOL_BG

  Background color of the {{ Symbol }} element.

• GBT_CAR_SIGN_SYMBOL_FG

  Foreground color of the {{ Symbol }} element.

• GBT_CAR_SIGN_SYMBOL_FM="bold"

  Formatting of the {{ Symbol }} element.

• GBT_CAR_SIGN_SYMBOL_FORMAT

  Format of the {{ Symbol }} element. The format is either {{ Admin }} if the UID is 0 or {{ User }} if the UID is not 0.

• GBT_CAR_SIGN_ADMIN_BG

  Background color of the {{ Admin }} element.

• GBT_CAR_SIGN_ADMIN_FG="red"

  Foreground color of the {{ Admin }} element.

• GBT_CAR_SIGN_ADMIN_FM

  Formatting of the {{ Admin }} element.

• GBT_CAR_SIGN_ADMIN_TEXT="#"

  Text content of the {{ Admin }} element.

• GBT_CAR_SIGN_USER_BG

  Background color of the {{ User }} element.

• GBT_CAR_SIGN_USER_FG="light_green"

  Foreground color of the {{ User }} element.

• GBT_CAR_SIGN_USER_FM

  Formatting of the {{ User }} element.

• GBT_CAR_SIGN_USER_TEXT="$"

  Text content of the {{ User }} element. The user name.

• GBT_CAR_SIGN_DISPLAY="1"

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_SIGN_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_SIGN_SEP

  Custom separator string for this car.

Car that visualizes return code of every command. By default, this car is displayed only when the return code is non-zero. If you want to display it even if the return code is zero, set the following variable:

export GBT_CAR_STATUS_DISPLAY="1"

Variables used by the car:

• GBT_CAR_STATUS_BG

  Background color of the car. It's either GBT_CAR_STATUS_OK_BG if the last command returned 0 return code otherwise the GBT_CAR_STATUS_ERROR_BG is used.

• GBT_CAR_STATUS_FG="default"

  Foreground color of the car. It's either GBT_CAR_STATUS_OK_FG if the last command returned 0 return code otherwise the GBT_CAR_STATUS_ERROR_FG is used.

• GBT_CAR_STATUS_FM="none"

  Formatting of the car. It's either GBT_CAR_STATUS_OK_FM if the last command returned 0 return code otherwise the GBT_CAR_STATUS_ERROR_FM is used.

• GBT_CAR_STATUS_FORMAT=" {{ Symbol }} "

  Format of the car. This can be changed to contain also the value of the return code:

  export GBT_CAR_STATUS_FORMAT=" {{ Symbol }} {{ Code }} "

• GBT_CAR_STATUS_SYMBOL_BG

  Background color of the {{ Symbol }} element.

• GBT_CAR_STATUS_SYMBOL_FG

  Foreground color of the {{ Symbol }} element.

• GBT_CAR_STATUS_SYMBOL_FM="bold"

  Formatting of the {{ Symbol }} element.

• GBT_CAR_STATUS_SYMBOL_FORMAT

  Format of the {{ Symbol }} element. The format is either {{ Error }} if the last command returned non zero return code otherwise {{ User }} is used.

• GBT_CAR_STATUS_CODE_BG="red"

  Background color of the {{ Code }} element.

• GBT_CAR_STATUS_CODE_FG="light_gray"

  Foreground color of the {{ Code }} element.

• GBT_CAR_STATUS_CODE_FM="none"

  Formatting of the {{ Code }} element.

• GBT_CAR_STATUS_CODE_TEXT

  Text content of the {{ Code }} element. The return code.

• GBT_CAR_STATUS_ERROR_BG="red"

  Background color of the {{ Error }} element.

• GBT_CAR_STATUS_ERROR_FG="light_gray"

  Foreground color of the {{ Error }} element.

• GBT_CAR_STATUS_ERROR_FM="none"

  Formatting of the {{ Error }} element.

• GBT_CAR_STATUS_ERROR_TEXT="✘"

  Text content of the {{ Error }} element.

• GBT_CAR_STATUS_OK_BG="green"

  Background color of the {{ Ok }} element.

• GBT_CAR_STATUS_OK_FG="light_gray"

  Foreground color of the {{ Ok }} element.

• GBT_CAR_STATUS_OK_FM="none"

  Formatting of the {{ Ok }} element.

• GBT_CAR_STATUS_OK_TEXT="✔"

  Text content of the {{ Ok }} element.

• GBT_CAR_STATUS_DISPLAY

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_STATUS_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_STATUS_SEP

  Custom separator string for this car.

Car that displays current date and time.

• GBT_CAR_TIME_BG="light_blue"

  Background color of the car.

• GBT_CAR_TIME_FG="light_gray"

  Foreground color of the car.

• GBT_CAR_TIME_FM="none"

  Formatting of the car.

• GBT_CAR_TIME_FORMAT=" {{ DateTime }} "

  Format of the car.

• GBT_CAR_TIME_DATETIME_BG

  Background color of the {{ DateTime }} element.

• GBT_CAR_TIME_DATETIME_FG

  Foreground color of the {{ DateTime }} element.

• GBT_CAR_TIME_DATETIME_FM

  Formatting of the {{ DateTime }} element.

• GBT_CAR_TIME_DATETIME_FORMAT="{{ Date }} {{ Time }}"

  Format of the {{ DateTime }} element.

• GBT_CAR_TIME_DATE_BG

  Background color of the {{ Date }} element.

• GBT_CAR_TIME_DATE_FG

  Foreground color of the {{ Date }} element.

• GBT_CAR_TIME_DATE_FM

  Formatting of the {{ Date }} element.

• GBT_CAR_TIME_DATE_FORMAT="Mon 02 Jan"

  Format of the {{ Date }} element. The format is using placeholders as described in the time.Format() Go function. For example January is a placeholder for current full month name and PM is a placeholder AM if the current time is before noon or PM if the current time is after noon. So in order to display date in the format of YYYY-MM-DD, the value of this variable should be 2006-01-02.

• GBT_CAR_TIME_TIME_BG

  Background color of the {{ Host }} element.

• GBT_CAR_TIME_TIME_FG="light_yellow"

  Foreground color of the {{ Host }} element.

• GBT_CAR_TIME_TIME_FM

  Formatting of the {{ Host }} element.

• GBT_CAR_TIME_TIME_FORMAT="15:04:05"

  Text content of the {{ Host }} element. The format principles are the same like in the case of the GBT_CAR_TIME_DATE_FORMAT variable above. So in order to display time in the 12h format, the value of this variable should be 03:04:05 PM.

• GBT_CAR_TIME_DISPLAY="1"

  Whether to display this car if it's in the list of cars (GBT_CARS).

• GBT_CAR_TIME_WRAP="0"

  Whether to wrap the prompt line in front of this car.

• GBT_CAR_TIME_SEP

  Custom separator string for this car.

It's possible to use GBT to generate prompt string and forward it to remote server via SSH so we can have GBT-like prompt also in the remote shell. The main limitation is that the text of the cars can only be dynamic if only prompt escape sequences recognized by the remote shell are used. As most of the remote servers have Bash as their default shell, we need to create Bash-compatible PS1 string.

The principle is that we need to create a file which we will use to configure the output of locally executed GBT as the PS1 for the remote server. This configuration also re-definition the TEXT fields form certain cars to use Bash escape sequences instead (e.g. \u for the user name). We write this configuration into the ~/.gbt.theme file like this:

cat <<END > ~/.gbt.theme
export GBT_CARS='Os, Time, Hostname, Dir, Sign'
export GBT_CAR_OS_NAME='cloud'
export GBT_CAR_TIME_FORMAT=' \t '
export GBT_CAR_HOSTNAME_USER_TEXT='\u'
export GBT_CAR_HOSTNAME_HOST_TEXT='\h'
export GBT_CAR_DIR_DIR_TEXT='\W'
export GBT_CAR_SIGN_SYMBOL_FORMAT='\\\$'
export GBT_SHELL='_bash'
END

Then we can tell SSH to execute remote command which consists of locally generated GBT output, which is written into a file on the remote server, and the Bash command which loads that generated file as its RC file:

ssh myserver -t "echo \"PS1='$(source ~/.gbt.theme; gbt)'\" > /tmp/.gbt; bash --rcfile /tmp/.gbt"

Similar principle is used to get the PS1 through the run of su command. We just need to run Bash command which loads the generated file as its RC file:

su -c 'bash --rcfile /tmp/.gbt' - myuser

The same principle can be used for sudo command:

sudo su -c 'bash --rcfile /tmp/.gbt' - myuser

To get GBT-like prompt inside a Docker container, we need to copy the generated file into the container and then execute Bash like in the case of su or sudo:

docker cp /tmp/.gbt pensive_pasteur:/tmp
docker exec -it pensive_pasteur /bin/bash --rcfile /tmp/.gbt

To get GBT-like prompt inside a Vagrant when running vagrant ssh, we can use the same approach like for SSH above:

vagrant ssh --command "echo \"PS1='$(source ~/.gbt.theme; gbt)'\" > /tmp/.gbt; bash --rcfile /tmp/.gbt"

More complete and seamless implementation of the above, including the passing of the PS1 string via docker, ssh, su, sudo and vagrant commands, is available as a part of this repo. You can start using it by doing the following:

export GBT__HOME="/usr/share/gbt"
source "$GBT__HOME/sources/prompt_forwarding/local"
alias docker="gbt_docker"
alias ssh="gbt_ssh"
alias su="gbt_su"
alias sudo="gbt_sudo"
alias vagrant="gbt_vagrant"

If you want to have the alias available only on the remote machine, prepend the alias by gbt___. For example to have the sudo alias, using the gbt_sudo function, available only on the remote machine, define the alias like this:

alias gbt__sudo="gbt_sudo"

Then just SSH to some remote server or enter some Docker container or Vagrant box and you should get GBT-like looking prompt:

Jiri Tyr

MIT