<s>
In	O
computing	O
,	O
help	O
is	O
a	O
command	B-Application
in	O
various	O
command	B-Application
line	I-Application
shells	B-Operating_System
such	O
as	O
COMMAND.COM	B-Operating_System
,	O
cmd.exe	B-Device
,	O
Bash	B-Operating_System
,	O
qshell	B-Operating_System
,	O
4DOS/4NT	O
,	O
Windows	B-Application
PowerShell	I-Application
,	O
Singularity	B-Operating_System
shell	I-Operating_System
,	O
Python	B-Language
,	O
MATLAB	B-Language
and	O
GNU	B-Language
Octave	I-Language
.	O
</s>
<s>
It	O
provides	O
online	B-Protocol
information	I-Protocol
about	O
available	O
commands	O
and	O
the	O
shell	O
environment	O
.	O
</s>
<s>
The	O
command	B-Application
is	O
available	O
in	O
operating	B-General_Concept
systems	I-General_Concept
such	O
as	O
Multics	B-Application
,	O
Heath	O
Company	O
HDOS	B-Application
,	O
DOS	B-Device
,	O
IBM	B-Application
OS/2	I-Application
,	O
eComStation	B-Device
,	O
ArcaOS	B-Device
,	O
IBM	B-Application
i	I-Application
,	O
Microsoft	B-Application
Windows	I-Application
,	O
ReactOS	B-Application
,	O
THEOS/OASIS	B-Device
,	O
Zilog	O
Z80-RIO	B-Device
,	O
Microware	B-Operating_System
OS-9	B-Operating_System
,	O
Stratus	B-General_Concept
OpenVOS	I-General_Concept
,	O
HP	B-Operating_System
MPE/iX	I-Operating_System
,	O
Motorola	O
VERSAdos	O
,	O
KolibriOS	B-Operating_System
and	O
also	O
in	O
the	O
DEC	O
RT-11	B-Operating_System
,	O
RSX-11	B-Application
,	O
TOPS-10	B-Operating_System
and	O
TOPS-20	B-Operating_System
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Furthermore	O
it	O
is	O
available	O
in	O
the	O
open	B-License
source	I-License
MS-DOS	B-Application
emulator	B-Application
DOSBox	B-Application
and	O
in	O
the	O
EFI	B-Architecture
shell	I-Architecture
.	O
</s>
<s>
On	O
Unix	B-Application
,	O
the	O
command	B-Application
is	O
part	O
of	O
the	O
Source	B-Device
Code	I-Device
Control	I-Device
System	I-Device
and	O
prints	O
help	O
information	O
for	O
the	O
SCCS	O
commands	O
.	O
</s>
<s>
The	O
Multics	B-Application
help	O
command	B-Application
prints	O
descriptions	O
of	O
system	O
commands/active	O
functions	O
and	O
subroutines	O
.	O
</s>
<s>
The	O
DEC	O
OS/8	B-Operating_System
CCL	B-Operating_System
help	O
command	B-Application
prints	O
information	O
on	O
specified	O
OS/8	B-Operating_System
programs	O
.	O
</s>
<s>
The	O
help	O
command	B-Application
is	O
available	O
in	O
MS-DOS	B-Application
5.x	O
and	O
later	O
versions	O
of	O
the	O
software	O
.	O
</s>
<s>
The	O
help	O
command	B-Application
with	O
a	O
'	O
command	B-Application
 '	O
parameter	O
would	O
give	O
help	O
on	O
a	O
specific	O
command	B-Application
.	O
</s>
<s>
If	O
no	O
arguments	O
are	O
provided	O
,	O
the	O
command	B-Application
lists	O
the	O
contents	O
of	O
DOSHELP.HLP	O
.	O
</s>
<s>
In	O
MS-DOS	B-Application
6.x	O
this	O
command	B-Application
exists	O
as	O
FASTHELP	O
.	O
</s>
<s>
The	O
MS-DOS	B-Application
6.xx	O
help	O
command	B-Application
uses	O
QBasic	B-Language
to	O
view	O
a	O
quickhelp	O
HELP.HLP	O
file	O
,	O
which	O
contains	O
more	O
extensive	O
information	O
on	O
the	O
commands	O
,	O
with	O
some	O
hyperlinking	O
etc	O
.	O
</s>
<s>
The	O
MS-DOS	B-Application
6.22	O
help	B-Protocol
system	I-Protocol
is	O
included	O
on	O
Windows	B-Application
9x	O
CD-ROM	O
versions	O
as	O
well	O
.	O
</s>
<s>
In	O
PC	B-Operating_System
DOS	I-Operating_System
5	O
and	O
6	O
help	O
is	O
the	O
same	O
form	O
as	O
MS-DOS	B-Application
5	O
help	O
command	B-Application
.	O
</s>
<s>
PC	B-Operating_System
DOS	I-Operating_System
7.xx	O
help	O
uses	O
view.exe	O
to	O
open	O
OS/2	B-Application
style	O
INF	B-Protocol
files	I-Protocol
(	O
cmdref.inf	O
,	O
dosrexx.inf	O
and	O
doserror.inf	O
)	O
,	O
opening	O
these	O
to	O
the	O
appropriate	O
pages	O
.	O
</s>
<s>
Like	O
the	O
rest	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
it	O
is	O
licensed	O
under	O
the	O
GPL	O
v3	O
.	O
</s>
<s>
In	O
DR-DOS	B-Application
,	O
help	O
is	O
a	O
batch	O
file	O
that	O
launches	O
DR-DOS	B-Application
'	O
internal	O
help	O
program	O
,	O
dosbook	O
.	O
</s>
<s>
Datalight	O
ROM-DOS	B-Operating_System
includes	O
an	O
implementation	O
of	O
the	O
command	B-Application
.	O
</s>
<s>
ROM-DOS	B-Operating_System
was	O
introduced	O
in	O
1989	O
as	O
an	O
MS-DOS	B-Application
compatible	O
operating	B-General_Concept
system	I-General_Concept
designed	O
for	O
embedded	O
systems	O
.	O
</s>
<s>
The	O
FreeDOS	B-Application
version	O
was	O
developed	O
by	O
Joe	O
Cosentino	O
.	O
</s>
<s>
The	O
4DOS/4NT	O
help	O
command	B-Application
uses	O
a	O
text	B-Application
user	I-Application
interface	I-Application
to	O
display	O
the	O
online	B-Protocol
help	I-Protocol
.	O
</s>
<s>
Used	O
without	O
parameters	O
,	O
help	O
lists	O
and	O
briefly	O
describes	O
every	O
system	B-Application
command	I-Application
.	O
</s>
<s>
Windows	O
NT-based	O
versions	O
use	O
MS-DOS	B-Application
5	O
style	O
help	O
.	O
</s>
<s>
Versions	O
before	O
Windows	B-Application
Vista	I-Application
also	O
have	O
a	O
Windows	B-Application
help	B-Protocol
file	I-Protocol
(	O
NTCMDS.HLP	O
or	O
NTCMDS.INF	O
)	O
in	O
a	O
similar	O
style	O
to	O
MS-DOS	B-Application
6	O
.	O
</s>
<s>
In	O
PowerShell	B-Application
,	O
help	O
is	O
a	O
short	O
form	O
(	O
implemented	O
as	O
a	O
PowerShell	B-Application
function	O
)	O
for	O
access	O
to	O
the	O
Get-Help	O
Cmdlet	O
.	O
</s>
<s>
Windows	B-Application
PowerShell	I-Application
includes	O
an	O
extensive	O
,	O
console-based	O
help	B-Protocol
system	I-Protocol
,	O
reminiscent	O
of	O
man	O
pages	O
in	O
Unix	B-Application
.	O
</s>
<s>
The	O
help	O
topics	O
include	O
help	O
for	O
cmdlets	O
,	O
providers	O
,	O
and	O
concepts	O
in	O
PowerShell	B-Application
.	O
</s>
<s>
In	O
Bash	B-Operating_System
,	O
the	O
builtin	O
command	B-Application
help	O
 '	O
lists	O
all	O
Bash	B-Operating_System
builtin	O
commands	O
if	O
used	O
without	O
arguments	O
.	O
</s>
<s>
Otherwise	O
,	O
it	O
prints	O
a	O
brief	O
summary	O
of	O
a	O
command	B-Application
.	O
</s>
<s>
Its	O
syntax	B-Application
is	O
:	O
</s>
<s>
HELP	O
is	O
a	O
DCL	B-Operating_System
utility	O
that	O
contains	O
information	O
on	O
the	O
use	O
of	O
commands	O
and	O
descriptions	O
of	O
some	O
OpenVMS	O
concepts	O
such	O
as	O
time	O
formats	O
and	O
lexical	O
functions	O
,	O
as	O
well	O
as	O
lists	O
of	O
commands	O
for	O
a	O
particular	O
purpose	O
(	O
HELP	O
Hints	O
)	O
.	O
</s>
<s>
The	O
command-syntax	O
is	O
:	O
</s>
<s>
command	B-Application
This	O
command-line	B-Application
argument	O
specifies	O
the	O
name	O
of	O
the	O
command	B-Application
about	O
which	O
information	O
is	O
to	O
be	O
displayed	O
.	O
</s>
