<s>
CMS	B-Application
EXEC	I-Application
,	O
or	O
EXEC	B-Application
,	O
is	O
an	O
interpreted	O
,	O
command	O
procedure	O
control	O
,	O
computer	O
scripting	B-Language
language	I-Language
used	O
by	O
the	O
CMS	B-Application
EXEC	I-Application
Processor	O
supplied	O
with	O
the	O
IBM	O
Virtual	O
Machine/Conversational	O
Monitor	O
System	O
(	O
VM/CMS	B-Application
)	O
operating	O
system	O
.	O
</s>
<s>
EXEC	B-Application
was	O
written	O
in	O
1966	O
by	O
Stuart	O
Madnick	O
at	O
MIT	O
on	O
the	O
model	O
of	O
CTSS	B-Operating_System
RUNCOM	B-Device
.	O
</s>
<s>
He	O
originally	O
called	O
this	O
processor	O
COMMAND	O
,	O
and	O
it	O
was	O
later	O
renamed	O
EXEC	B-Application
.	O
</s>
<s>
CMS	B-Application
EXEC	I-Application
has	O
been	O
superseded	O
by	O
EXEC	B-Application
2	I-Application
and	O
REXX	B-Language
.	O
</s>
<s>
All	O
three	O
—	O
CMS	B-Application
EXEC	I-Application
,	O
EXEC	B-Application
2	I-Application
and	O
REXX	B-Language
—	O
continue	O
to	O
be	O
supported	O
by	O
the	O
IBM	B-Operating_System
CMS	I-Operating_System
product	I-Operating_System
.	O
</s>
<s>
EXEC	B-Application
processes	O
lines	O
up	O
to	O
130	O
characters	O
long	O
when	O
entered	O
from	O
a	O
terminal	B-General_Concept
,	O
or	O
72	O
characters	O
when	O
read	O
from	O
a	O
file	O
.	O
</s>
<s>
A	O
label	O
consisting	O
of	O
a	O
dash	O
followed	O
by	O
up	O
to	O
seven	O
alphanumeric	O
characters	O
can	O
prefix	O
a	O
CMS	O
command	O
or	O
an	O
EXEC	B-Application
control	O
statement	O
.	O
</s>
<s>
Variables	O
can	O
be	O
either	O
user-defined	O
variables	O
or	O
pre-defined	O
(	O
"	O
special	O
"	O
)	O
EXEC	B-Application
variables	O
.	O
</s>
<s>
If	O
they	O
contain	O
EXEC	B-Application
variables	O
the	O
variables	O
are	O
replaced	O
by	O
their	O
value	O
.	O
</s>
<s>
Comments	O
in	O
EXEC	B-Application
files	O
begin	O
with	O
an	O
asterisk	B-Language
in	O
column	O
one	O
.	O
</s>
<s>
If	O
the	O
first	O
data	O
item	O
on	O
a	O
line	O
is	O
not	O
an	O
asterisk	B-Language
or	O
ampersand	O
the	O
EXEC	B-Application
processor	O
considers	O
the	O
line	O
to	O
be	O
a	O
CMS	O
command	O
and	O
passes	O
it	O
to	O
CMS	O
for	O
immediate	O
execution	O
.	O
</s>
<s>
An	O
assignment	O
statement	O
assigns	O
a	O
value	O
to	O
an	O
EXEC	B-Application
variable	O
.	O
</s>
<s>
A	O
statement	O
where	O
the	O
first	O
data	O
item	O
is	O
an	O
EXEC	B-Application
control	O
word	O
and	O
the	O
second	O
is	O
not	O
an	O
equals	O
sign	O
is	O
assumed	O
to	O
be	O
a	O
control	O
statement	O
.	O
</s>
<s>
EXEC	B-Application
control	O
words	O
:	O
</s>
<s>
&	O
BEGTYPE	O
-	O
heads	O
a	O
series	O
of	O
lines	O
to	O
be	O
typed	O
on	O
the	O
user	O
's	O
terminal	B-General_Concept
.	O
</s>
<s>
&	O
EXIT	O
-	O
exits	O
the	O
current	O
EXEC	B-Application
file	O
,	O
and	O
optionally	O
sets	O
a	O
return	O
code	O
.	O
</s>
<s>
&	O
GOTO	O
-	O
branches	O
to	O
another	O
location	O
in	O
the	O
current	O
EXEC	B-Application
file	O
.	O
</s>
<s>
&	O
READ	O
-	O
reads	O
one	O
or	O
more	O
lines	O
from	O
the	O
user	O
's	O
terminal	B-General_Concept
.	O
</s>
<s>
&	O
SPACE	O
-	O
types	O
a	O
specified	O
number	O
of	O
blank	O
lines	O
on	O
the	O
user	O
's	O
terminal	B-General_Concept
.	O
</s>
<s>
&	O
TIME	O
-	O
specifies	O
what	O
timing	O
information	O
is	O
to	O
be	O
typed	O
on	O
the	O
user	O
's	O
terminal	B-General_Concept
following	O
the	O
execution	O
of	O
each	O
CMS	O
command	O
.	O
</s>
<s>
&	O
TYPE	O
types	O
a	O
line	O
on	O
the	O
user	O
's	O
terminal	B-General_Concept
.	O
</s>
<s>
The	O
EXEC	B-Application
interpreter	O
provides	O
a	O
few	O
"	O
built-in	O
"	O
or	O
predefined	O
functions	O
:	O
</s>
<s>
PROFILE	O
EXEC	B-Application
is	O
an	O
EXEC	B-Application
that	O
is	O
automatically	O
executed	O
when	O
a	O
user	O
logs	O
on	O
to	O
tailor	O
their	O
environment	O
.	O
</s>
<s>
A	O
simple	O
PROFILE	O
EXEC	B-Application
might	O
look	O
like	O
the	O
following	O
:	O
</s>
