<s>
A	O
file	B-Application
change	I-Application
log	I-Application
tracks	O
changes	O
to	O
the	O
namespace	O
(	O
files	O
and	O
directories	O
)	O
of	O
a	O
file	B-Application
system	I-Application
.	O
</s>
<s>
Depending	O
on	O
the	O
implementation	O
,	O
a	O
file	B-Application
change	I-Application
log	I-Application
will	O
record	O
changes	O
such	O
as	O
creates	O
,	O
links	O
,	O
unlinks	O
(	O
deletions	O
)	O
,	O
renamed	O
files	O
,	O
data	O
changes	O
,	O
and	O
metadata	O
changes	O
(	O
for	O
example	O
,	O
ACLs	O
and	O
permissions	O
)	O
.	O
</s>
<s>
A	O
file	B-Application
change	I-Application
log	I-Application
can	O
be	O
accessed	O
as	O
a	O
file	O
in	O
the	O
file	B-Application
system	I-Application
,	O
or	O
hidden	O
and	O
accessed	O
only	O
programmatically	O
.	O
</s>
<s>
A	O
file	B-Application
change	I-Application
log	I-Application
differs	O
from	O
a	O
file	B-Application
system	I-Application
's	O
journal	B-Application
.	O
</s>
<s>
First	O
,	O
some	O
applications	O
must	O
scan	O
an	O
entire	O
file	B-Application
system	I-Application
to	O
discover	O
changes	O
since	O
their	O
last	O
scan	O
.	O
</s>
<s>
By	O
reading	O
a	O
file	B-Application
change	I-Application
log	I-Application
,	O
they	O
can	O
avoid	O
this	O
scan	O
.	O
</s>
<s>
Scanning	O
applications	O
include	O
backup	B-Application
utilities	I-Application
,	O
web	B-Application
crawler	I-Application
,	O
search	B-Application
engines	I-Application
,	O
and	O
replication	O
programs	O
.	O
</s>
<s>
Second	O
,	O
the	O
log	O
can	O
serve	O
as	O
an	O
audit	O
record	O
for	O
activity	O
in	O
a	O
file	B-Application
system	I-Application
.	O
</s>
