fish-shell/share/functions/help.fish
2019-12-01 17:31:41 +01:00

209 lines
8.4 KiB
Fish

function help --description 'Show help for the fish shell'
set -l options 'h/help'
argparse -n help --max-args=1 $options -- $argv
or return
if set -q _flag_help
__fish_print_help help
return 0
end
set -l fish_help_item $argv[1]
set -l help_topics syntax completion editor job-control todo bugs history killring help
set -a help_topics color prompt title variables builtin-overview changes expand
set -a help_topics expand-variable expand-home expand-brace expand-wildcard
set -a help_topics expand-command-substitution expand-process
#
# Find a suitable browser for viewing the help pages.
# The first thing we try is $fish_help_browser.
set -l fish_browser $fish_help_browser
# A list of graphical browsers we know about.
set -l graphical_browsers htmlview x-www-browser firefox galeon mozilla
set -a graphical_browsers konqueror epiphany opera netscape rekonq google-chrome chromium-browser
# On mac we may have to write a temporary file that redirects to the desired
# help page, since `open` will drop fragments from file URIs (issue #4480).
set -l need_trampoline
if not set -q fish_browser[1]
if set -q BROWSER
# User has manually set a preferred browser, so we respect that
set fish_browser $BROWSER
else
# No browser set up, inferring.
# We check a bunch and use the last we find.
# Check for a text-based browser.
for i in htmlview www-browser links elinks lynx w3m
if type -q -f $i
set fish_browser $i
break
end
end
# If we are in a graphical environment, check if there is a graphical
# browser to use instead.
if test -n "$DISPLAY" -a \( "$XAUTHORITY" = "$HOME/.Xauthority" -o "$XAUTHORITY" = "" \)
for i in $graphical_browsers
if type -q -f $i
set fish_browser $i
break
end
end
end
# If we have an open _command_ we use it - otherwise it's our function,
# which might not have a backend to use.
# Note that we prefer xdg-open, because this open might also be a symlink to "openvt"
# like it is on Debian.
if command -sq open
set fish_browser open
# The open command needs a trampoline because the macOS version can't handle #-fragments.
set need_trampoline 1
end
# If the OS appears to be Windows (graphical), try to use cygstart
if type -q cygstart
set fish_browser cygstart
# If xdg-open is available, just use that
# but only if an X session is running
else if type -q xdg-open; and set -q -x DISPLAY
set fish_browser xdg-open
end
# Try to find cmd.exe via $PATH or one of the paths that it's often at.
#
# We use this instead of xdg-open because that's useless without a backend
# like wsl-open which we'll check in a minute.
if set -l cmd (command -s cmd.exe /mnt/c/Windows/System32/cmd.exe)
# Use the first of these.
set fish_browser $cmd[1]
end
if type -q wsl-open
set fish_browser wsl-open
end
end
end
if not set -q fish_browser[1]
printf (_ '%s: Could not find a web browser.\n') help
printf (_ 'Please set the variable $BROWSER or fish_help_browser and try again.\n\n')
return 1
end
# In Cygwin, start the user-specified browser using cygstart,
# only if a Windows browser is to be used.
if type -q cygstart
if test $fish_browser != "cygstart"
and not command -sq $fish_browser[1]
# Escaped quotes are necessary to work with spaces in the path
# when the command is finally eval'd.
set fish_browser cygstart \"$fish_browser\"
else
set need_trampoline 1
end
end
switch "$fish_help_item"
case "."
set fish_help_page "cmds/source.html"
case globbing
set fish_help_page "index.html#expand"
case (__fish_print_commands)
set fish_help_page "cmds/$fish_help_item.html"
case $help_topics
set fish_help_page "index.html#$fish_help_item"
case 'tut_*'
set fish_help_page "tutorial.html#$fish_help_item"
case tutorial
set fish_help_page "tutorial.html"
case "*"
# If $fish_help_item is empty, this will fail,
# and $fish_help_page will end up as index.html
if type -q -f "$fish_help_item"
# Prefer to use fish's man pages, to avoid
# the annoying useless "builtin" man page bash
# installs on OS X
set -l man_arg "$__fish_data_dir/man/man1/$fish_help_item.1"
if test -f "$man_arg"
man $man_arg
return
end
end
set fish_help_page "index.html"
end
set -l page_url
if test -f $__fish_help_dir/index.html
# Help is installed, use it
set page_url file://$__fish_help_dir/$fish_help_page
# For Windows (Cygwin and WSL), we need to convert the base help dir to a Windows path before converting it to a file URL
# but only if a Windows browser is being used
if type -q cygpath
and string match -qr "cygstart" $fish_browser[1]
set page_url file://(cygpath -m $__fish_help_dir)/$fish_help_page
else if type -q wslpath
and string match -qr '.exe' $fish_browser[1]
set page_url file://(wslpath -w $__fish_help_dir)/$fish_help_page
end
else
# Go to the web. Only include one dot in the version string
set -l version_string (echo $version| cut -d . -f 1,2)
set page_url https://fishshell.com/docs/$version_string/$fish_help_page
# We don't need a trampoline for a remote URL.
set need_trampoline
end
if set -q need_trampoline[1]
# If string replace doesn't replace anything, we don't actually need a
# trampoline (they're only needed if there's a fragment in the path)
if set -l clean_url (string match -re '#' $page_url)
# Write a temporary file that will redirect where we want.
set -q TMPDIR
or set -l TMPDIR /tmp
set -l tmpdir (mktemp -d $TMPDIR/help.XXXXXX)
set -l tmpname $tmpdir/help.html
echo '<meta http-equiv="refresh" content="0;URL=\''$clean_url'\'" />' >$tmpname
set page_url file://$tmpname
# For Windows (Cygwin and WSL), we need to convert the base help dir to a Windows path before converting it to a file URL
# but only if a Windows browser is being used
if type -q cygpath
and string match -qr "cygstart" $fish_browser[1]
set page_url file://(cygpath -m $tmpname)
else if type -q wslpath
and string match -qr '.exe' $fish_browser[1]
set page_url file://(wslpath -w $tmpname)
end
end
end
# URL may contain # (anchor) or $ (hidden share in Windows)
set page_url (string escape $page_url)
# cmd.exe needs more coaxing.
if string match -qr 'cmd.exe$' -- $fish_browser[1]
eval $fish_browser /c "start $page_url"
# If browser is known to be graphical, put into background
else if contains -- $fish_browser[1] $graphical_browsers
switch $fish_browser[1]
case 'htmlview' 'x-www-browser'
printf (_ 'help: Help is being displayed in your default browser.\n')
case '*'
printf (_ 'help: Help is being displayed in %s.\n') $fish_browser[1]
end
eval "$fish_browser $page_url &"
else
# Work around lynx bug where <div class="contents"> always has the same formatting as links (unreadable)
# by using a custom style sheet. See https://github.com/fish-shell/fish-shell/issues/4170
if string match -q 'lynx*' -- $fish_browser
set fish_browser $fish_browser -lss={$__fish_data_dir}/lynx.lss
end
eval $fish_browser $page_url
end
end