A friendly interactive shell


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Encouraged by a tweet, intrigued by the homepage, and this blog, I started playing around with the fish shell. Reading through the tutorial and documentation, I often felt that the right choices were done, even though sometimes a little brave (e. g. with changing && to ; and).

I have been using zsh for a while now after being a bash user for a long time and work on macOS, Linux, and FreeBSD and I fancy a nice prompt, in particular including repository status, number of background jobs, last commands error code, etc.

I gave fish a shot and came up with the configuration in the following listing, which is small, simple to set up and feels like a somewhat clean configuration. The reason for that might be that the git prompt is a first class citizen in fish and that fish’s scripting language seems well designed.

# Fish git prompt
set __fish_git_prompt_showdirtystate 'yes'
set __fish_git_prompt_showstashstate 'yes'
set __fish_git_prompt_showuntrackedfiles 'yes'
set __fish_git_prompt_showupstream 'yes'
set __fish_git_prompt_color -b grey
set __fish_git_prompt_color_branch -b grey yellow
set __fish_git_prompt_color_upstream_ahead -b grey green
set __fish_git_prompt_color_upstream_behind -b grey red
set __fish_git_prompt_show_informative_status 'yes'

# Status Chars
set __fish_git_prompt_char_upstream_prefix ':'
set __fish_git_prompt_char_upstream_ahead 'A'
set __fish_git_prompt_char_upstream_behind 'B'
set __fish_git_prompt_char_stateseparator '.'
set __fish_git_prompt_char_dirtystate 'm'
set __fish_git_prompt_char_invalidstate 'x'
set __fish_git_prompt_char_stagedstate 'M'
set __fish_git_prompt_char_untrackedfiles '?'
set __fish_git_prompt_char_cleanstate ''
set __fish_git_prompt_char_stashstate '^'
set __fish_git_prompt_describe_style 'branch'

function fish_prompt
  set -l last_status $status

  if not test $last_status -eq 0
    set_color -b $fish_color_error white
    printf ' %s ' (echo $last_status)
    set_color normal

  set -l jobcount (jobs | wc -l)
  printf '[%d]' $jobcount

  printf '%s ' (__fish_git_prompt)
  printf '%s ' (date "+%y-%m-%d %H:%M:%S")
  set_color green
  printf  '%s\n' (hostname)

  set_color $fish_color_cwd
  printf '%s\n> ' (prompt_pwd)

  set_color normal

The first two paragraphs are configuration settings of the git prompt, while the ‘actual work’ is done in the function fish_prompt. It contains the last command’s return code with red background (if non-zero), the number of jobs in the background, a detailed git status prompt, the date and time when the prompt was printed, the hostname and in the next line the working directory.

Very compact, very nice. Cheers,