helm/zsh/completion.zsh

# Return if requirements are not found.
[[ "$TERM" == 'dumb' ]] && return 1

# Load and initialize the completion system ignoring insecure directories.
autoload -Uz compinit && compinit -i

## Options
setopt COMPLETE_ALIASES    # Complete from both ends of a word.
setopt COMPLETE_IN_WORD    # Complete from both ends of a word.
setopt ALWAYS_TO_END       # Move cursor to the end of a completed word.
setopt PATH_DIRS           # Perform path search even on command names with slashes.
setopt AUTO_MENU           # Show completion menu on a successive tab press.
setopt AUTO_LIST           # Automatically list choices on ambiguous completion.
setopt AUTO_PARAM_SLASH    # If completed parameter is a directory, add a trailing slash.
unsetopt MENU_COMPLETE     # Do not autoselect the first completion entry.
unsetopt FLOW_CONTROL      # Disable start/stop characters in shell editor.
unsetopt CASE_GLOB

# Use caching to make completion for commands such as dpkg and apt usable.
zstyle ':completion::complete:*' use-cache on
zstyle ':completion::complete:*' cache-path "${ZDOTDIR:-$HOME}/.zgen/.zcompcache"

# Case-insensitive (all), partial-word, and then substring completion.
zstyle ':completion:*' matcher-list '' \
       'm:{a-z\-}={A-Z\_}' \
       'r:[^[:alpha:]]||[[:alpha:]]=** r:|=* m:{a-z\-}={A-Z\_}' \
       'r:[[:ascii:]]||[[:ascii:]]=** r:|=* m:{a-z\-}={A-Z\_}'

# zstyle ':completion:*' matcher-list 'r:[[:ascii:]]||[[:ascii:]]=** r:|=* m:{a-z\-}={A-Z\_}'

# Group matches and describe.
zstyle ':completion:*:*:*:*:*' menu select
zstyle ':completion:*:matches' group 'yes'
zstyle ':completion:*:options' description 'yes'
zstyle ':completion:*:options' auto-description '%d'
zstyle ':completion:*:corrections' format ' %F{green}-- %d (errors: %e) --%f'
zstyle ':completion:*:descriptions' format ' %F{yellow}-- %d --%f'
zstyle ':completion:*:messages' format ' %F{purple} -- %d --%f'
zstyle ':completion:*:warnings' format ' %F{red}-- no matches found --%f'
zstyle ':completion:*:default' list-prompt '%S%M matches%s'
zstyle ':completion:*' format ' %F{yellow}-- %d --%f'
zstyle ':completion:*' group-name ''
zstyle ':completion:*' verbose yes

# Fuzzy match mistyped completions.
zstyle ':completion:*' completer _complete _match _approximate
zstyle ':completion:*:match:*' original only
zstyle ':completion:*:approximate:*' max-errors 1 numeric

# Increase the number of errors based on the length of the typed word.
zstyle -e ':completion:*:approximate:*' max-errors 'reply=($((($#PREFIX+$#SUFFIX)/3))numeric)'

# Don't complete unavailable commands.
zstyle ':completion:*:functions' ignored-patterns '(_*|pre(cmd|exec))'

# Array completion element sorting.
zstyle ':completion:*:*:-subscript-:*' tag-order indexes parameters

# Directories
zstyle ':completion:*:default' list-colors ${(s.:.)LS_COLORS}
zstyle ':completion:*:*:cd:*' tag-order local-directories directory-stack path-directories
zstyle ':completion:*:*:cd:*:directory-stack' menu yes select
zstyle ':completion:*:-tilde-:*' group-order 'named-directories' 'path-directories' 'users' 'expand'
zstyle ':completion:*' squeeze-slashes true

# History
zstyle ':completion:*:history-words' stop yes
zstyle ':completion:*:history-words' remove-all-dups yes
zstyle ':completion:*:history-words' list false
zstyle ':completion:*:history-words' menu yes

# Environmental Variables
zstyle ':completion::*:(-command-|export):*' fake-parameters ${${${_comps[(I)-value-*]#*,}%%,*}:#-*-}

# Populate hostname completion.
zstyle -e ':completion:*:hosts' hosts 'reply=(
  ${=${=${=${${(f)"$(cat {/etc/ssh_,~/.ssh/known_}hosts(|2)(N) 2>/dev/null)"}%%[#| ]*}//\]:[0-9]*/ }//,/ }//\[/ }
  ${=${(f)"$(cat /etc/hosts(|)(N) <<(ypcat hosts 2>/dev/null))"}%%\#*}
  ${=${${${${(@M)${(f)"$(cat ~/.ssh/config 2>/dev/null)"}:#Host *}#Host }:#*\**}:#*\?*}}
)'

# Don't complete uninteresting users...
zstyle ':completion:*:*:*:users' ignored-patterns \
  adm amanda apache avahi beaglidx bin cacti canna clamav daemon \
  dbus distcache dovecot fax ftp games gdm gkrellmd gopher \
  hacluster haldaemon halt hsqldb ident junkbust ldap lp mail \
  mailman mailnull mldonkey mysql nagios \
  named netdump news nfsnobody nobody nscd ntp nut nx openvpn \
  operator pcap postfix postgres privoxy pulse pvm quagga radvd \
  rpc rpcuser rpm shutdown squid sshd sync uucp vcsa xfs '_*'

# ... unless we really want to.
zstyle '*' single-ignored show

# Ignore multiple entries.
zstyle ':completion:*:(rm|kill|diff):*' ignore-line other
zstyle ':completion:*:rm:*' file-patterns '*:all-files'

# Kill
zstyle ':completion:*:*:*:*:processes' command 'ps -u $LOGNAME -o pid,user,command -w'
zstyle ':completion:*:*:kill:*:processes' list-colors '=(#b) #([0-9]#) ([0-9a-z-]#)*=01;36=0=01'
zstyle ':completion:*:*:kill:*' menu yes select
zstyle ':completion:*:*:kill:*' force-list always
zstyle ':completion:*:*:kill:*' insert-ids single

# Man
zstyle ':completion:*:manuals' separate-sections true
zstyle ':completion:*:manuals.(^1*)' insert-sections true

# Media Players
zstyle ':completion:*:*:mpg123:*' file-patterns '*.(mp3|MP3):mp3\ files *(-/):directories'
zstyle ':completion:*:*:mpg321:*' file-patterns '*.(mp3|MP3):mp3\ files *(-/):directories'
zstyle ':completion:*:*:ogg123:*' file-patterns '*.(ogg|OGG|flac):ogg\ files *(-/):directories'
zstyle ':completion:*:*:mocp:*' file-patterns '*.(wav|WAV|mp3|MP3|ogg|OGG|flac):ogg\ files *(-/):directories'

# SSH/SCP/RSYNC
zstyle ':completion:*:(scp|rsync):*' tag-order 'hosts:-host:host hosts:-domain:domain hosts:-ipaddr:ip\ address *'
zstyle ':completion:*:(scp|rsync):*' group-order users files all-files hosts-domain hosts-host hosts-ipaddr
zstyle ':completion:*:ssh:*' tag-order 'hosts:-host:host hosts:-domain:domain hosts:-ipaddr:ip\ address *'
zstyle ':completion:*:ssh:*' group-order users hosts-domain hosts-host users hosts-ipaddr
zstyle ':completion:*:(ssh|scp|rsync):*:hosts-host' ignored-patterns '*(.|:)*' loopback ip6-loopback localhost ip6-localhost broadcasthost
zstyle ':completion:*:(ssh|scp|rsync):*:hosts-domain' ignored-patterns '<->.<->.<->.<->' '^[-[:alnum:]]##(.[-[:alnum:]]##)##' '*@*'
zstyle ':completion:*:(ssh|scp|rsync):*:hosts-ipaddr' ignored-patterns '^(<->.<->.<->.<->|(|::)([[:xdigit:].]##:(#c,2))##(|%*))' '127.0.0.<->' '255.255.255.255' '::1' 'fe80::*'