Convert bash function to fish's [closed]

Question

Can someone help me convert this bash function to fish? It would also be nice if you could explain what these do like "${@%%.app}”, 's/ /.*/g’, "$@\” etc.

bid() {
    local shortname location

    # combine all args as regex
    # (and remove ".app" from the end if it exists due to autocomplete)
    shortname=$(echo "${@%%.app}"|sed 's/ /.*/g')
    # if the file is a full match in apps folder, roll with it
    if [ -d "/Applications/$shortname.app" ]; then
        location="/Applications/$shortname.app"
    else # otherwise, start searching
        location=$(mdfind -onlyin /Applications -onlyin ~/Applications -onlyin /Developer/Applications 'kMDItemKind==Application'|awk -F '/' -v re="$shortname" 'tolower($NF) ~ re {print $0}'|head -n1)
    fi
    # No results? Die.
    [[ -z $location || $location = "" ]] && echo "$1 not found, I quit" && return
    # Otherwise, find the bundleid using spotlight metadata
    bundleid=$(mdls -name kMDItemCFBundleIdentifier -r "$location")
    # return the result or an error message
    [[ -z $bundleid || $bundleid = "" ]] && echo "Error getting bundle ID for \"$@\"" || echo "$location: $bundleid”
}

Thanks very much in advance.

Answer 1

Some notes on the differences:

• setting variables
  • bash: var=value
  • fish: set var value
• functions
  • bash

    funcName() {
        ...
    }
    

  • fish

    function funcName
        ...
    end
    

• function arguments
  • bash: "$@", "$1", "$2", ...
  • fish: $argv, $argv[1], $argv[2], ...
• function local variables
  • bash: local var
  • fish: set -l var
• conditionals I
  • bash: [[ ... ]] and test ... and [ ... ]
  • fish: test ... and [ ... ], no [[ ... ]]
• conditionals II
  • bash: if cond; then cmds; fi
  • fish: if cond; cmds; end
• conditionals III
  • bash: cmd1 && cmd2
  • fish: cmd1; and cmd2
  • fish (as of fish 3.0): cmd1 && cmd2
• command substitution
  • bash: output=$(pipeline)
  • fish: set output (pipeline)
• process substitution
  • bash: join <(sort file1) <(sort file2)
  • fish: join (sort file1 | psub) (sort file2 | psub)

Documentation

• bash: https://www.gnu.org/software/bash/manual/bashref.html
• fish: http://fishshell.com/docs/current/index.html and https://fishshell.com/docs/current/fish_for_bash_users.html