#!/bin/bash
#
# list_id_in_kext
#

###
### settings
###

set -e                # exit on any uncaught error
set +o histexpand     # don't expand history expressions
shopt -s nocasematch  # case-insensitive regular expressions

###
### global variables
###

kextdir=''

# prefer GNU xargs
xargs="$(/usr/bin/which gxargs || printf '/usr/bin/xargs')"

###
### functions
###

bundle_id_source_1 () {
    /usr/bin/find "$kextdir" -name Info.plist -print0 |                                \
    "$xargs" -0 -I {} /usr/libexec/PlistBuddy {} -c 'Print :CFBundleIdentifier'
}

merge_sources () {
    /usr/bin/sort | /usr/bin/uniq
}

clean_sources () {
    /usr/bin/egrep -v '^com\.apple\.'
}

mark_up_sources () {
    /usr/bin/perl -pe 's{\n}{\000}sg' |                                                \
    "$xargs" -0 -I{} -n1 /bin/bash -c                                                  \
      'printf "{}"; /bin/test "$(/usr/sbin/kextstat -kl -b "{}" | /usr/bin/wc -l)" -gt 0 && printf " (+)"; printf "\n"'
}

###
### main
###

_list_id_in_kext () {

    kextdir="$1"
    if [[ -h "$kextdir" ]]; then
        kextdir="$(/usr/bin/readlink "$kextdir")"
    fi

    {
      # emit strings that look like bundle ids
      bundle_id_source_1;
    } |                     \
    clean_sources |         \
    merge_sources |         \
    mark_up_sources

}

# process args
if [[ $1 =~ ^-+h(elp)?$ || -z "$1" ]]; then
    printf "list_id_in_kext <file.kext>

Given a Kernel Extension (kext) bundle dir on disk, extract the
associated kext Bundle ID, which may be useful in a Cask uninstall
stanza, eg

    uninstall :kext => 'kext.id.goes.here'

The kext need not be loaded for this script to work.

If a given kext is currently loaded, it will be followed by a plus
symbol '(+)' in the output. This can be verified via the command

    /usr/sbin/kextstat -kl -b 'kext.id.goes.here'

See CONTRIBUTING.md and 'man kextstat' for more information.

"
    exit
fi

# dispatch main
_list_id_in_kext "${@}"

#