<s>
md5deep	B-Language
is	O
a	O
software	O
package	O
used	O
in	O
the	O
computer	O
security	O
,	O
system	B-Application
administration	I-Application
and	O
computer	O
forensics	O
communities	O
to	O
run	O
large	O
numbers	O
of	O
files	B-Operating_System
through	O
any	O
of	O
several	O
different	O
cryptographic	O
digests	B-Error_Name
.	O
</s>
<s>
The	O
name	O
md5deep	B-Language
is	O
misleading	O
.	O
</s>
<s>
Since	O
version	O
2.0	O
,	O
the	O
md5deep	B-Language
package	O
contains	O
several	O
different	O
programs	B-Application
able	O
to	O
perform	O
MD5	B-Algorithm
,	O
SHA-1	B-Algorithm
,	O
SHA-256	B-Algorithm
,	O
Tiger192	B-Algorithm
and	O
Whirlpool	B-Algorithm
digests	B-Error_Name
,	O
each	O
of	O
them	O
named	O
by	O
the	O
digest	O
type	O
followed	O
by	O
the	O
word	O
"	O
deep	O
"	O
.	O
</s>
<s>
Thus	O
,	O
the	O
name	O
may	O
confuse	O
some	O
people	O
into	O
thinking	O
it	O
only	O
provides	O
the	O
MD5	B-Algorithm
algorithm	O
when	O
the	O
package	O
supports	O
many	O
more	O
.	O
</s>
<s>
md5deep	B-Language
can	O
be	O
invoked	O
in	O
several	O
different	O
ways	O
.	O
</s>
<s>
Typically	O
users	O
operate	O
it	O
recursively	O
,	O
where	O
md5deep	B-Language
walks	O
through	O
one	O
directory	B-Application
at	O
a	O
time	O
giving	O
digests	B-Error_Name
of	O
each	O
file	O
found	O
,	O
and	O
recursing	O
into	O
any	O
subdirectories	B-Application
within	O
.	O
</s>
<s>
Its	O
recursive	O
behavior	O
is	O
approximately	O
a	O
depth-first	B-Algorithm
search	I-Algorithm
,	O
which	O
has	O
the	O
benefit	O
of	O
presenting	O
files	B-Operating_System
in	O
lexicographical	O
order	O
.	O
</s>
<s>
On	O
Unix-like	B-Operating_System
systems	I-Operating_System
,	O
similar	O
functionality	O
can	O
be	O
often	O
obtained	O
by	O
combining	O
find	B-Application
with	O
hashing	O
utilities	O
such	O
as	O
md5sum	B-Device
,	O
sha256sum	O
or	O
tthsum	O
.	O
</s>
<s>
md5deep	B-Language
exists	O
for	O
Windows	B-Application
and	O
most	O
Unix-based	O
systems	O
,	O
including	O
OS	B-Operating_System
X	I-Operating_System
.	O
</s>
<s>
It	O
is	O
present	O
in	O
OS	B-Operating_System
X	I-Operating_System
's	O
Fink	B-Application
,	O
Homebrew	B-Application
and	O
MacPorts	B-Application
projects	O
.	O
</s>
<s>
Binary	O
packages	O
exist	O
for	O
most	O
free	B-Application
Unix	B-Application
systems	I-Application
.	O
</s>
<s>
Many	O
vendors	O
initially	O
resist	O
including	O
md5deep	B-Language
as	O
they	O
mistakenly	O
believe	O
its	O
functions	O
can	O
be	O
reproduced	O
with	O
one	O
line	O
of	O
shell	O
scripting	O
.	O
</s>
<s>
Because	O
md5deep	B-Language
was	O
written	O
by	O
an	O
employee	O
of	O
the	O
U.S.	O
government	O
,	O
on	O
government	O
time	O
,	O
it	O
is	O
in	O
the	O
public	O
domain	O
.	O
</s>
