A Powerline style prompt for your shell

A Powerline like prompt for Bash,
ZSH and Fish. Based on Powerline-Shell by @banga.
Ported to golang by @justjanne.

• Shows some important details about the git/hg branch (see below)
• Changes color if the last command exited with a failure code
• If you're too deep into a directory tree, shortens the displayed path with an ellipsis
• Shows the current Python virtualenv environment
• Shows if you are in a nix shell
• It's easy to customize and extend. See below for details.

Table of Contents

• Version Control
• Installation
  • Precompiled Binaries
  • Other Platforms
  • Bash
  • ZSH
  • Fish
  • Nix
• Customization
• License

Version Control

All of the version control systems supported by powerline shell give you a
quick look into the state of your repo:

• The current branch is displayed and changes background color when the
  branch is dirty.
• When the local branch differs from the remote, the difference in number
  of commits is shown along with ⇡ or ⇣ indicating whether a git push
  or pull is pending

In addition, git has a few extra symbols:

• ✎ -- a file has been modified, but not staged for commit
• ✔ -- a file is staged for commit
• ✼ -- a file has conflicts
• + -- untracked files are present
• ⚑ -- stash is present

Each of these will have a number next to it if more than one file matches.

Installation

powerline-go uses ANSI color codes, these should nowadays work everywhere,
but you may have to set your $TERM to xterm-256color for it to work.

If you want to use the "patched" mode (which is the default, and provides
improved UI), you'll need to install a powerline font, either as fallback,
or by patching the font you use for your terminal: see
powerline-fonts.
Alternatively you can use "compatible" or "flat" mode.

Precompiled Binaries

I provide precompiled binaries for x64 Linux and macOS in the
releases tab

Other Platforms

• Install (and update) the package with

go get -u github.com/justjanne/powerline-go

• By default it will be in $GOPATH/bin, if you want to change that, you can set
  your $GOPATH and/or $GOBIN, but will need to change the path in the
  following scripts, too.

Bash

Add the following to your .bashrc (or .profile on Mac):

function _update_ps1() {
    PS1="$($GOPATH/bin/powerline-go -error $?)"
}

if [ "$TERM" != "linux" ] && [ -f "$GOPATH/bin/powerline-go" ]; then
    PROMPT_COMMAND="_update_ps1; $PROMPT_COMMAND"
fi

Currently, right prompt support is not available when using bash.

ZSH

Add the following to your .zshrc:

function powerline_precmd() {
    PS1="$($GOPATH/bin/powerline-go -error $? -shell zsh)"
}

function install_powerline_precmd() {
  for s in "${precmd_functions[@]}"; do
    if [ "$s" = "powerline_precmd" ]; then
      return
    fi
  done
  precmd_functions+=(powerline_precmd)
}

if [ "$TERM" != "linux" ]; then
    install_powerline_precmd
fi

Fish

Redefine fish_prompt in ~/.config/fish/config.fish:

function fish_prompt
    eval $GOPATH/bin/powerline-go -error $status -shell bare
end

Nix

When using nix-shell --pure, powerline-go will not be accessible, and
your prompt will disappear.

To work around this you can add this snippet to your .bashrc,
which should re-enable the prompt in most cases:

# Workaround for nix-shell --pure
if [ "$IN_NIX_SHELL" == "pure" ]; then
    if [ -x "$HOME/.nix-profile/bin/powerline-go" ]; then
        alias powerline-go="$HOME/.nix-profile/bin/powerline-go"
    elif [ -x "/run/current-system/sw/bin/powerline-go" ]; then
        alias powerline-go="/run/current-system/sw/bin/powerline-go"
    fi
fi

Customization

There are a few optional arguments which can be seen by running
powerline-go -help. These can be used by changing the command you have set
in your shell’s init file.

Usage of ./powerline-go:
  -colorize-hostname
         Colorize the hostname based on a hash of itself
  -condensed
         Remove spacing between segments
  -cwd-max-depth int
         Maximum number of directories to show in path
         (default 5)
  -cwd-max-dir-size int
         Maximum number of letters displayed for each directory in the path
         (default -1)
  -cwd-mode string
         How to display the current directory
         (valid choices: fancy, plain, dironly)
         (default "fancy")
  -duration string
         The elapsed clock-time of the previous command
  -duration-min string
         The minimal time a command has to take before the duration segment is shown (default "0")
  -east-asian-width
         Use East Asian Ambiguous Widths
  -error int
         Exit code of previously executed command
  -eval
         Output prompt in 'eval' format.
  -ignore-repos string
         A list of git repos to ignore. Separate with ','.
         Repos are identified by their root directory.
  -max-width int
         Maximum width of the shell that the prompt may use, in percent. Setting this to 0 disables the shrinking subsystem.
  -mode string
         The characters used to make separators between segments.
         (valid choices: patched, compatible, flat)
         (default "patched")
  -modules string
         The list of modules to load, separated by ','
         (valid choices: aws, cwd, docker, dotenv, duration, exit, git, gitlite, hg, host, jobs, kube, load, newline, nix-shell, node, perlbrew, perms, plenv, root, shell-var, ssh, svn, termtitle, terraform-workspace, time, user, venv, vgo)
         (default "venv,user,host,ssh,cwd,perms,git,hg,jobs,exit,root")
  -modules-right string
         The list of modules to load anchored to the right, for shells that support it, separated by ','
         (valid choices: aws, cwd, docker, dotenv, duration, exit, git, gitlite, hg, host, jobs, kube, load, newline, nix-shell, node, perlbrew, perms, plenv, root, shell-var, ssh, svn, termtitle, terraform-workspace, time, user, venv, vgo)
  -newline
         Show the prompt on a new line
  -numeric-exit-codes
         Shows numeric exit codes for errors.
  -path-aliases string
         One or more aliases from a path to a short name. Separate with ','.
         An alias maps a path like foo/bar/baz to a short name like FBB.
         Specify these as key/value pairs like foo/bar/baz=FBB.
         Use '~' for your home dir. You may need to escape this character to avoid shell substitution.
  -priority string
         Segments sorted by priority, if not enough space exists, the least priorized segments are removed first. Separate with ','
         (valid choices: aws, cwd, docker, dotenv, duration, exit, git, gitlite, hg, host, jobs, kube, load, newline, nix-shell, node, perlbrew, perms, plenv, root, shell-var, ssh, svn, termtitle, terraform-workspace, time, user, venv, vgo)
         (default "root,cwd,user,host,ssh,perms,git-branch,git-status,hg,jobs,exit,cwd-path")
  -shell string
         Set this to your shell type
         (valid choices: bare, bash, zsh)
         (default "bash")
  -shell-var string
         A shell variable to add to the segments.
  -shorten-eks-names
         Shortens names for EKS Kube clusters.
  -shorten-gke-names
         Shortens names for GKE Kube clusters.
  -static-prompt-indicator
         Always show the prompt indicator with the default color, never with the error color
  -theme string
         Set this to the theme you want to use
         (valid choices: default, low-contrast)
         (default "default")
  -truncate-segment-width int
         Minimum width of a segment, segments longer than this will be shortened if space is limited. Setting this to 0 disables it.
         (default 16)

Eval

If using eval and -modules-right is desired, the shell setup must be modified slightly, as shown below:

Bash

Add the following to your .bashrc (or .profile on Mac):

function _update_ps1() {
    eval "$($GOPATH/bin/powerline-go -error $? -shell bash -eval -modules-right git)"
}

if [ "$TERM" != "linux" ] && [ -f "$GOPATH/bin/powerline-go" ]; then
    PROMPT_COMMAND="_update_ps1; $PROMPT_COMMAND"
fi

ZSH

Add the following to your .zshrc:

function powerline_precmd() {
    eval "$($GOPATH/bin/powerline-go -error $? -shell zsh -eval -modules-right git)"
}

function install_powerline_precmd() {
  for s in "${precmd_functions[@]}"; do
    if [ "$s" = "powerline_precmd" ]; then
      return
    fi
  done
  precmd_functions+=(powerline_precmd)
}

if [ "$TERM" != "linux" ]; then
    install_powerline_precmd
fi

Fish

Eval mode (and modules-right support) for Fish is not currently available.

Path Aliases

The point of the path aliases feature is to allow you to replace long paths
with a shorter string that you can understand more quickly. This is useful if
you're often in deep path hierarchies that end up consuming most of your
terminal width, even when some portions are replaced by an ellipsis.

For example, you might want to replace the string $GOPATH/src/github.com with
@GOPATH-GH. When you're in a directory like
$GOPATH/src/github.com/justjanne/powerline-go, you'll instead see @GOPATH-GH > justjanne > powerline-go in the shell prompt.

Aliases are defined as comma-separated key value pairs, like this:

powerline-go ... -path-aliases \$GOPATH/src/github.com=@GOPATH-GH,\~/work/projects/foo=@FOO,\~/work/projects/bar=@BAR

Note that you should use ~ instead of /home/username when specifying the
path. Also make sure to escape the ~ character. Otherwise your shell will
perform interpolation on it before powerline-go can see it!

Duration

The duration segment requires some assistance from the shell. The shell must have a hook that gets executed immediately before the command.

Bash

Bash 4.4 includes an easy way to get a start-time, using $PS0. However, not all operating systems come with a sufficiently recent version of Bash installed. This example only has seconds precision. Add or modify your .bashrc file to include the following:

INTERACTIVE_BASHPID_TIMER="/tmp/${USER}.START.$$"

PS0='$(echo $SECONDS > "$INTERACTIVE_BASHPID_TIMER")'

function _update_ps1() {
  local __ERRCODE=$?

  local __DURATION=0
  if [ -e $INTERACTIVE_BASHPID_TIMER ]; then
    local __END=$SECONDS
    local __START=$(cat "$INTERACTIVE_BASHPID_TIMER")
    __DURATION="$(($__END - ${__START:-__END}))"
    rm -f "$INTERACTIVE_BASHPID_TIMER"
  fi

  PS1="$($GOPATH/bin/powerline-go -modules duration -duration $__DURATION -error $__ERRCODE -shell bash)"
}

if [ "$TERM" != "linux" ] && [ -f "$GOPATH/bin/powerline-go" ]; then
  PROMPT_COMMAND="_update_ps1; $PROMPT_COMMAND"
fi

Zsh

Using $EPOCHREALTIME requires loading the 'datetime' module in your .zshrc file, for example:

zmodload zsh/datetime

function preexec() {
  __TIMER=$EPOCHREALTIME
}

function powerline_precmd() {
  local __ERRCODE=$?
  local __DURATION=0

  if [ -n $__TIMER ]; then
    local __ERT=$EPOCHREALTIME
    __DURATION="$(($__ERT - ${__TIMER:-__ERT}))"
  fi

  PS1="$(powerline-go -modules duration -duration $__DURATION -error $__ERRCODE -shell zsh)"
  unset __TIMER
}

If the 'datetime' module is unavailable or unwanted, you may replace $EPOCHREALTIME with $SECONDS, at the loss of precision.

Fish

The fish prompt, in ~/.config/fish/config.fish, will require a minimum of changes, as Fish automatically provides $CMD_DURATION, although with only milliseconds accuracy.

function fish_prompt
    set duration (math -s6 "$CMD_DURATION / 1000")
    $GOPATH/bin/powerline-go -modules duration -duration $duration -error $status -shell bare
end

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.