.Dd March 6, 2009 
.Os Darwin
.Dt MKEXTUNPACK 8
.Sh NAME
.Nm mkextunpack
.Nd extract or list the contents of a multikext (mkext) archive
.Sh SYNOPSIS
.Nm
.Op Fl v
.Op Fl a Ar arch
.Op Fl d Ar output_directory
.Ar mkext_file
.Sh DESCRIPTION
The
.Nm
program lists the contents of a multikext file,
.Ar mkext_file ,
or unarchives the contents into
.Ar output_directory
(which must exist).
The
.Fl v
option causes
.Nm
to print the name if each kext as it finds them.
.Sh DIAGNOSTICS
.Nm
exits with a zero status upon success.
Upon failure, it prints an error message
and exits with a nonzero status.
.Pp
With a nonsegreated format 1 mkext file,
wherein each kext may contain a universal binary,
.Nm
simply unpacks the contents.
With an mkext file segregated by architecture
(that is, with distinct internal archives of architecture-specific kexts),
.Nm
attempts by default to unpack or list kexts
for the current machine's architecture.
To choose a particular architecture
to extract or list,
use the
.Fl a
option.
.Pp
There is no simple way to unpack a segregated mkext file
into a set of kexts with universal binaries,
but you can unpack each of its component architectures
to separate directories for examination.
.Sh SEE ALSO 
.Xr kextcache 8
.Sh BUGS
Many single-letter options are inconsistent in meaning
with (or directly contradictory to) the same letter options
in other kext tools.
.Pp
For version 1 mkext files, note that the file format
doesn't record the original filenames
of the kexts, so
.Nm
has to guess at what they are.
It does this by using the value of the CFBundleExecutable
property of the kext's info dictionary
(Project Builder sets this to the base name of the kext
bundle by default, but the developer can change it).
If that property doesn't exist, the last component of the
CFBundleIdentifier is used.
Duplicates have an incrementing index appended to the name.
Kexts that have no CFBundleExecutable or CFBundleIdentifier property
are named
.Do Ns Pa NameUnknown- Ns Ar n Ns Pa .kext Dc Ns ,
where
.Ar n
is a number.