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100 lines
2.8 KiB
Fish
100 lines
2.8 KiB
Fish
function __fish_print_help --description "Print help message for the specified fish function or builtin" --argument item
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# special support for builtin_help_get()
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set -l tty_width
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if test "$item" = "--tty-width"
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set tty_width $argv[2]
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set item $argv[3]
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end
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if test "$item" = '.'
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set item source
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end
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# Do nothing if the file does not exist
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if not test -e "$__fish_datadir/man/man1/$item.1"
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return
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end
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set -l IFS \n\ \t
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# Render help output, save output into the variable 'help'
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set -l help
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set -l cols
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set -l rLL
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if test "$tty_width" -gt 0
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set cols $tty_width
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else if command test -t 1
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# We want to simulate `man`'s dynamic line length, because
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# defaulting to 80 kind of sucks.
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# Note: using `command test` instead of `test` because `test -t 1`
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# doesn't seem to work right.
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# Note: grab the size from the stdout terminal in case it's somehow
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# different than the stdin of fish.
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# use fd 3 to copy our stdout because we need to pipe the output of stty
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begin
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stty size 0<&3 | read __ cols
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end 3<&1
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end
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if test -n "$cols"
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set cols (expr $cols - 4) # leave a bit of space on the right
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set rLL -rLL=$cols[1]n
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end
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set help (nroff -man -t $rLL "$__fish_datadir/man/man1/$item.1" ^/dev/null)
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# The original implementation trimmed off the top 5 lines and bottom 3 lines
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# from the nroff output. Perhaps that's reliable, but the magic numbers make
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# me extremely nervous. Instead, let's just strip out any lines that start
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# in the first column. "normal" manpages put all section headers in the first
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# column, but fish manpages only leave NAME like that, which we want to trim
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# away anyway.
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#
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# While we're at it, let's compress sequences of blank lines down to a single
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# blank line, to duplicate the default behavior of `man`, or more accurately,
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# the `-s` flag to `less` that `man` passes.
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set -l state blank
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for line in $help
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# categorize the line
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set -l line_type
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switch $line
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case ' *' \t\*
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# starts with whitespace, check if it has non-whitespace
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printf "%s\n" $line | read -l word __
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if test -n $word
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set line_type normal
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else
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# lines with just spaces probably shouldn't happen
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# but let's consider them to be blank
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set line_type blank
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end
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case ''
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set line_type blank
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case '*'
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# not leading space, and not empty, so must contain a non-space
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# in the first column. That makes it a header/footer.
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set line_type meta
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end
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switch $state
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case normal
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switch $line_type
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case normal
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printf "%s\n" $line
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case blank
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set state blank
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case meta
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# skip it
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end
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case blank
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switch $line_type
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case normal
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echo # print the blank line
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printf "%s\n" $line
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set state normal
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case blank meta
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# skip it
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end
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end
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end | ul # post-process with `ul`, to interpret the old-style grotty escapes
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echo # print a trailing blank line
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end
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