<s>
The	O
(	O
from	O
change	O
group	O
)	O
command	B-Application
may	O
be	O
used	O
by	O
unprivileged	O
users	O
on	O
various	O
operating	B-General_Concept
systems	I-General_Concept
to	O
change	O
the	O
group	O
associated	O
with	O
a	O
file	B-Application
system	I-Application
object	O
(	O
such	O
as	O
a	O
computer	B-Operating_System
file	I-Operating_System
,	O
directory	B-Application
,	O
or	O
link	O
)	O
to	O
one	O
of	O
which	O
they	O
are	O
a	O
member	O
.	O
</s>
<s>
A	O
file	B-Application
system	I-Application
object	O
has	O
3	O
sets	O
of	O
access	O
permissions	O
,	O
one	O
set	O
for	O
the	O
owner	O
,	O
one	O
set	O
for	O
the	O
group	O
and	O
one	O
set	O
for	O
others	O
.	O
</s>
<s>
The	O
command	B-Application
was	O
originally	O
developed	O
as	O
part	O
of	O
the	O
Unix	B-Application
operating	I-Application
system	I-Application
by	O
AT&T	O
Bell	O
Laboratories	O
.	O
</s>
<s>
It	O
is	O
also	O
available	O
in	O
the	O
Plan	B-Operating_System
9	I-Operating_System
and	O
Inferno	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
and	O
in	O
most	O
Unix-like	B-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
The	O
command	B-Application
has	O
also	O
been	O
ported	O
to	O
the	O
IBM	B-Application
i	I-Application
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
group	O
parameter	O
specifies	O
the	O
new	O
group	O
with	O
which	O
the	O
files	O
or	O
directories	B-Application
should	O
be	O
associated	O
.	O
</s>
<s>
It	O
may	O
either	O
be	O
a	O
symbolic	O
name	O
or	O
an	O
identifier	B-Application
.	O
</s>
<s>
The	O
FSO	O
specifies	O
one	O
or	O
more	O
file	B-Application
system	I-Application
objects	O
,	O
which	O
may	O
be	O
the	O
result	O
of	O
a	O
glob	B-Language
expression	O
like	O
.	O
</s>
<s>
recurse	O
through	O
subdirectories	B-Application
.	O
</s>
<s>
The	O
above	O
command	B-Application
changes	O
the	O
group	O
associated	O
with	O
file	O
prog.conf	O
from	O
to	O
(	O
provided	O
the	O
executing	O
user	O
is	O
a	O
member	O
of	O
that	O
group	O
)	O
.	O
</s>
