Table of Contents

Shell layer

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shell.png

1 Description

This layer configures the various shells available in Emacs.

1.1 Features:

  • Shell integration

2 Install

To use this configuration layer, add it to your ~/.spacemacs. You will need to add shell to the existing dotspacemacs-configuration-layers list in this file.

2.1 Install vterm

vterm is the latest addition to Emacs' set of terminal emulators and the only one to be implemented in C, leveraging libvterm. It is the only one in Emacs at the moment to be as fast as a standalone terminal with full support for ncurses, vim, htop and the likes.

On its first run, vterm will automatically compile its dynamic library, for which dependencies are needed. For more details, head to the official docs.

2.1.1 Check that your Emacs supports dynamic modules

You can check if your Emacs supports loading dynamic libraries by checking if the system-configuration-features variable contains the string MODULES. If not, you need to get a version of Emacs that supports it or compile it from source supplying the ./configure --with-module option at configure time.

2.1.2 Install CMake 3.11 or higher

  1. macOS
    brew install cmake
    
  2. Ubuntu
    sudo apt install cmake
    

2.1.3 Install libtool

If the libtool command does not exist in your system (usually in /usr/bin/libtool), you need to install it:

  1. Ubuntu
    sudo apt install libtool-bin
    

2.1.4 Install libvterm

  1. macOS
    brew install libvterm
    
  2. Ubuntu
    sudo apt install libvterm-dev
    

    In other distros, find it and install it in your favorite package manager.

  3. Windows

    Not supported at the moment, but possibly coming up.

3 Configuration

3.1 Default shell

Emacs supports five types of shells/terminals:

  • the Emacs shell (eshell)
  • the inferior shell
  • the terminal emulator
  • the ANSI terminal emulator
  • the vterm terminal emulator based on the C library libvterm

You can find a quick introductions to them here.

To define the default shell you can set the layer variable shell-default-shell to the following variables:

  • eshell (default on Windows)
  • shell
  • term
  • ansi-term (default on Linux/macOS)
  • multi-term
  • vterm
(setq-default dotspacemacs-configuration-layers
  '((shell :variables shell-default-shell 'eshell)))

The default shell is quickly accessible via a the default shortcut key ~SPC '​~.

3.2 Default shell position, width, and height

It is possible to choose where the shell should pop up by setting the variable shell-default-position to either top, bottom, left, right, or full. Default value is bottom. It is also possible to set the default height in percents with the variable shell-default-height. Default value is 30. You can also set a default width in percents with the variable shell-default-width, which has a default value of 30 and will take effect if your shell is positioned on the left or the right.

(setq-default dotspacemacs-configuration-layers
  '((shell :variables
           shell-default-position 'bottom
           shell-default-height 30)))

(setq-default dotspacemacs-configuration-layers
  '((shell :variables
           shell-default-position 'right
           shell-default-width 40)))

3.3 Set shell for term, ansi-term and vterm

The default shell can be set by setting the variable shell-default-term-shell. Default value is /bin/bash.

(setq-default dotspacemacs-configuration-layers
  '((shell :variables shell-default-term-shell "/bin/bash")))

3.4 Set shell for multi-term

The default shell can be set by setting the variable multi-term-program. Default value is /bin/bash.

(setq-default dotspacemacs-configuration-layers
  '((shell :variables multi-term-program "/bin/bash")))

3.5 Width of the shell popup buffers

By default the popup buffer spans the full width of the current frame, if you prefer to spans only the width of the current window then set the layer variable shell-default-full-span to nil.

(setq-default dotspacemacs-configuration-layers
  '((shell :variables shell-default-full-span nil)))

3.6 Enable em-smart in Eshell

From the em-smart documentation:

The best way to get a sense of what this code is trying to do is by using it. Basically, the philosophy represents a blend between the ease of use of modern day shells, and the review-before-you-proceed mentality of Plan 9's 9term.

In a nutshell, when em-smart is enabled point won't jump at the end of the buffer when a command is executed, it will stay at the same command prompt used to execute the command. This allows to quickly edit the last command in the case of a mistake. If there is no mistake and you directly type a new command then the prompt will jump to the next prompt at the end of the buffer.

To enable em-smart put the following layer variable to non-nil:

(setq-default dotspacemacs-configuration-layers
  '((shell :variables shell-enable-smart-eshell t)))

3.7 Protect your Eshell prompt

Comint mode (Shell mode) has good support for Evil mode as it inhibits movement commands over the prompt. This has the added benefit that Evil mode functions work sensibly. E.g. you can press cc in normal state i.e. evil-change-whole-line to kill the current input and start typing a new command. In Eshell you also kill the prompt, which is often unintended.

By default this layer also protects the eshell prompt. If you want to disable this protection you can set the variable shell-protect-eshell-prompt to nil.

(setq-default dotspacemacs-configuration-layers
  '((shell :variables shell-protect-eshell-prompt nil)))

3.8 Fish shell and ansi-term

Making fish shell to work with ansi-term may be a challenge, here are some pointers to save you time to setup your environment correctly.

First be sure ~/.terminfo is setup correctly by running:

tic -o ~/.terminfo $TERMINFO/e/eterm-color.ti

You can locate the eterm-colors.ti file with:

locate eterm-color.ti

Then setup your fish configuration file (usually at ~/.config/fish/config.fish)

# emacs ansi-term support
if test -n "$EMACS"
  set -x TERM eterm-color
end

# this function may be required
function fish_title
  true
end

Finally you may need to toggle truncated lines for some prompts to work correctly, in the function dotspacemacs/user-config of your dotfile add:

(add-hook 'term-mode-hook 'spacemacs/toggle-truncate-lines-on)

3.9 Close window with terminal

If you want its window to close when the terminal terminates, set the following layer variable to non-nil:

(setq-default dotspacemacs-configuration-layers
  '((shell :variables close-window-with-terminal t)))

This is only applied to term and ansi-term modes.

4 Eshell

Some advanced configuration is setup for eshell in this layer:

  • some elisp functions aliases for quick access
    • s for magit-status in the current directory (when the git layer is installed)
    • d for dired
    • e to find a file via a new buffer
    • z for quickly jumping to a previously visited directory
  • optional configuration for em-smart (see Install section for more info)
  • support for visual commands via em-term
  • working directory sensitive prompt via eshell-prompt-extras
  • advanced help support via esh-help (enable el-doc support in eshell)
  • add support for auto-completion via company (when the auto-completion layer is installed)
  • pressing i in normal state will automatically jump to the prompt

5 Key bindings

Key binding Description
~SPC '​~ Open, close or go to the default shell
~SPC p '​~ Open a shell in the project's root
SPC a s e Open, close or go to an eshell
SPC a s i Open, close or go to a shell
SPC a s m Open, close or go to a multi-term
SPC a s t Open, close or go to a ansi-term
SPC a s T Open, close or go to a term
TAB browse completion with helm
SPC m H browse history with helm (works in eshell and shell)
SPC a s v Open, close or go to a vterm
C-j next item in history
C-k previous item in history

Note: You can open multiple shells using a numerical prefix argument, for instance pressing ~2 SPC '​~ will a second default shell, the number of shell is indicated on the mode-line.

Note: Use the universal prefix argument ~SPC u SPC '​~ to open the shell in the current buffer instead of a popup.

5.1 Multi-term

Key binding Description
SPC m c create a new multi-term
SPC m C switch multi-term char mode
SPC m l switch multi-term to line mode
SPC m n go to next multi-term
SPC m N or SPC m p go to previous multi-term
SPC p $ t run multi-term shell in root

5.2 Eshell

Key binding Description
SPC m H or M-l shell commands history using a helm or ivy buffer

Author: root

Created: 2019-11-10 Sun 14:17

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