fish-shell/share/completions/mkvextract.fish

# Sample output of 'mkvmerge -i file.mkv'
#
# File 'file.mkv': container: Matroska
# Track ID 0: video (MPEG-4p10/AVC/h.264)
# Track ID 1: audio (AAC)
# Track ID 2: subtitles (SubStationAlpha)
# Attachment ID 1: type 'application/x-truetype-font', size 53532 bytes, file name 'some_font.ttf'
# Chapters: 7 entires

function __fish_mkvextract_find_matroska_in_args
    set -l cmd (commandline -opc)
    if not set -q cmd[3]
        return 1
    end
    for c in $cmd[3..-1]
        set -l skip_next 1
        test $skip_next -eq 0; and set skip_next 1; and continue
        switch $c
            # General options with an argument we need to skip
            case "--ui-language" "--command-line-charset" "--output-charset" "-r" "--redirect-output" "-c" "--blockadd" "--simple-language"
                set skip_next 0
                continue
            # these behave like commands and everything after them is ignored
            case "-h" "--help" "-V" "--version"
                return 1
            case "*"
                if test -f "$c"
                    echo $c
                    return 0
                end
                continue
        end
    end
    return 1
end

function __fish_mkvextract_print_attachments
    if set -l matroska (__fish_mkvextract_find_matroska_in_args)
        if set -l info (mkvmerge -i $matroska)
            string match 'Attachment ID*' -- $info | string replace -r '.*?(\d+).*? type \'(.*?)\'.*?file name \'(.*?)\'' '$1:\t$3 ($2)'
        end
    end
end

function __fish_mkvextract_print_tracks
    if set -l matroska (__fish_mkvextract_find_matroska_in_args)
        if set -l info (mkvmerge -i $matroska)
            string match 'Track ID*' -- $info | string replace -r '.*?(\d+): (.*)' '$1:\t$2'
        end
    end
end

# simple options
complete -f -c mkvextract -s V -l "version" -d "Show version information"
complete -f -c mkvextract -s h -l "help"    -d "Show help"
# commands
complete -f -c mkvextract -n "test (count (commandline -opc)) -lt 2" -a "tracks"       -d "Extract tracks to external files"
complete -f -c mkvextract -n "test (count (commandline -opc)) -lt 2" -a "tags"         -d "Extract tags as XML"
complete -f -c mkvextract -n "test (count (commandline -opc)) -lt 2" -a "attachments"  -d "Extract attachments"
complete -f -c mkvextract -n "test (count (commandline -opc)) -lt 2" -a "chapters"     -d "Extract chapters as XML"
complete -f -c mkvextract -n "test (count (commandline -opc)) -lt 2" -a "cuesheet"     -d "Extract chapters and tags as CUE sheet"
complete -f -c mkvextract -n "test (count (commandline -opc)) -lt 2" -a "timecodes_v2" -d "Extract timecodes of a track as timecode v2 file"
complete -f -c mkvextract -n "test (count (commandline -opc)) -lt 2" -a "cues"         -d "Extract cue information as text file"
# dynamic tracks and attachments completions
complete -f -c mkvextract -n "__fish_seen_subcommand_from tracks timecodes_v2 cues" -a "(__fish_mkvextract_print_tracks)"
complete -f -c mkvextract -n "__fish_seen_subcommand_from attachments"              -a "(__fish_mkvextract_print_attachments)"
# options common to all commands
complete -f -c mkvextract -n "test (count (commandline -opc)) -ge 2"    -s f -l "parse-fully"          -d "Parse the whole file instead of relying on the index"
complete -f -c mkvextract -n "test (count (commandline -opc)) -ge 2"    -s v -l "verbose"              -d "Increase verbosity"
complete -f -c mkvextract -n "test (count (commandline -opc)) -ge 2"    -s q -l "quiet"                -d "Suppress status output"
complete -f -c mkvextract -n "test (count (commandline -opc)) -ge 2" -r      -l "ui-language"          -d "Force the translations for 'code' to be used"
complete -f -c mkvextract -n "test (count (commandline -opc)) -ge 2" -r      -l "command-line-charset" -d "Charset for strings on the command line"
complete -f -c mkvextract -n "test (count (commandline -opc)) -ge 2" -r      -l "output-charset"       -d "Outputs messages in specified charset"
complete -f -c mkvextract -n "test (count (commandline -opc)) -ge 2" -r -s r -l "redirect-output"      -d "Redirect all messages into a file"
# command-specific options
complete -f -c mkvextract -n "__fish_seen_subcommand_from tracks"   -r -s c                      -d "Convert text subtitles to a charset"
complete -f -c mkvextract -n "__fish_seen_subcommand_from tracks"           -l "cuesheet"        -d "Also try to extract the CUE sheet"
complete -f -c mkvextract -n "__fish_seen_subcommand_from tracks"   -r      -l "blockadd"        -d "Keep only the BlockAdditions up to the specified level"
complete -f -c mkvextract -n "__fish_seen_subcommand_from tracks"           -l "raw"             -d "Extract the data to a raw file"
complete -f -c mkvextract -n "__fish_seen_subcommand_from tracks"           -l "fullraw"         -d "Extract the data to a raw file including the CodecPrivate as header"
complete -f -c mkvextract -n "__fish_seen_subcommand_from chapters"    -s s -l "simple"          -d "Exports the chapter information in a simple format"
complete -f -c mkvextract -n "__fish_seen_subcommand_from chapters" -r      -l "simple-language" -d "Uses the chapter names of the specified language"