Can an Xcode .mobileprovision file be ‘installed’ from the command line?

If you don’t want to download external dependencies (like Ben did), the following should work in most cases:

uuid=`grep UUID -A1 -a adhoc.mobileprovision | grep -io "[-A-F0-9]\{36\}"`
cp adhoc.mobileprovision ~/Library/MobileDevice/Provisioning\ Profiles/$uuid.mobileprovision

Note that a UUID is composed of hexadecimal digits so the correct range is [-A-F0-9] and not [-A-Z0-9].

Bonus: Download and install profiles

Using the cupertino tool, the following snippet downloads all your distribution profiles from the Developer Portal and installs them.

ios profiles:download:all --type distribution

for file in *.*provision*; do
    uuid=`grep UUID -A1 -a "$file" | grep -io "[-A-F0-9]\{36\}"`
    extension="${file##*.}"
    echo "$file -> $uuid"
    mv -f "$file" ~/Library/MobileDevice/Provisioning\ Profiles/"$uuid.$extension"
done

cupertino (the ios command) can be installed with sudo gem install cupertino.