Is there a way to auto-complete the open command in Terminal?

I frequently use the open -a command in Terminal to open applications via ssh. How do I make it auto-complete an application's name?

_complete_open() {
        COMPREPLY=()
        local cur="${COMP_WORDS[$COMP_CWORD]}"
        local prev="${COMP_WORDS[COMP_CWORD-1]}"
        [[ "$cur" == -* || "$prev" != '-a' ]] && return
        apps="$(mdfind kMDItemKind==Application -onlyin /Applications -onlyin ~/Applications -onlyin /Developer -onlyin ~/Developer | grep -v '/.*/.*/.*/.*/' | sed -E 's|.*/||g;s|\.app$||g' | uniq)"$'Finder\nArchive Utility\nCharacterPalette\nKeyboardViewer'
        local IFS=$'\n'
        if [[ "${cur:0:1}" = '"' || "${cur:0:1}" = "'" ]]; then
            quote="${cur:0:1}"
            cur="${cur:1}"
        fi
        local found="$(grep -i "^$cur" <<< "$apps")"
        if [[ "$quote" == '"' ]]; then
            found="$(sed "s|^|\"|g;s|$|\"|g" <<< "$found")"
        elif [[ "$quote" == "'" ]]; then
            found="$(sed "s|^|'|g;s|$|'|g" <<< "$found")"
        else
            found="$(sed 's| |\\ |g' <<< "$found")"
        fi
        COMPREPLY=($found)
}

complete -o default -F _complete_open open

Third version, which should now both be case insensitive and work within quotes.

Add the following to your .bash_profile or .bashrc and launch a new session:

function _complete_open {
    cur=$2
    COMPREPLY=( );

    [[ "$COMP_WORDS" = "open" ]] || return
    [[ "${COMP_WORDS[ $(( $COMP_CWORD - 1 )) ]}" = "-a" ]] || return

    OLDIFS="$IFS"
    IFS=$'\n'
    local _part="${COMP_WORDS[$COMP_CWORD]}"

    if [[ "${_part:0:1}" = '"' || "${_part:0:1}" = "'" ]] ; then
        COMPREPLY=( $( compgen -W "$( mdfind kMDItemKind==Application | sed -e 's|.*/||g' -e 's|.app$||' | sort -u )" -- $cur ) )
    else
        COMPREPLY=( $( compgen -W "$( mdfind kMDItemKind==Application | sed -e 's|.*/||g' -e 's|.app$||' -e 's| |\\\\ |g' | sort -u )" -- $cur ) )
    fi
    IFS="$OLDIFS"
}

complete -o default -F _complete_open open

No need to install anything. This works with bash out of the box.

It will only autocomplete program names if the previous option is -a and otherwise show default behavior, e.g. return a list of all files in the current directory or complete the current path prefix.

The results are generated from system_profiler SPApplicationsDataType, which is the easiest way to get all applications that can be launched this way on your system like that. The list is processed to only return the program names, which can contain spaces and can be different from the bundle names (even when ignoring .app suffix)

Usage: Type open -a, followed by a space, followed by pressing Tab or Esc (twice on my system, not sure if it's everywhere).

Example showing all the helper applications for my scanner:

$ open -a Scan
Scan to E-mail          Scan to Excel           Scan to Folder          Scan to Print           Scan to Searchable PDF  Scan to Word            ScanSnap Manager

Drawbacks and problems of this solution:

• There are tons of programs on your system you might not be aware of, like everything in /System/Library/CoreServices. You might not want to list all of them. OTOH, it's really easy to see and launch e.g. CharacterPalette or KeyboardViewer this way. *Configure the mdfind call(s) appropriately with the -onlyin argument.

• It's kind of slow, due to system_profiler SPApplicationsDataType. You might need to wait a second or two before completion shows up. Now uses mdfind to quickly get the programs. Thanks @Lri

• It can handle spaces in application names, and quotation enclosed program names, but it's rather hacky. It requires the quote to be the first character: While Scan" to "P is valid in bash, this program will not detect it. Completion does not work after an escaped space either (e.g. Scan\ to), use quotation marks in such cases ("Scan to). Support for escaped spaces is only good to complete DVD to DVD\ Player.