Chapter 5
MS-DOS COMMANDS
There
are
two
types
of MS-DOS commands, internal
and
exter-
nal.
Internal
commands
are
the
simpler, more commonly
used
commands. When you
list
a directory, you cannot see
these
com-
mands. When you
enter
them, they execute immediately.
External
commands reside on disks
as
program
files. Therefore,
MS-DOS
must
read
them
from disk before
it
can
execute them.
If
the
disk
containing
the
command is not
in
the
drive,
the
sys-
tem
cannot find
and
execute
the
command.
Note: Unless MS-DOS knows
in
which directory or
drive to
search
for
external
commands,
it
cannot exe-
cute
them. (See
the
PATH command.)
Any filename
that
has
an
extension of .com, .exe, or .bat is con-
sidered
an
external
command. For example,
programs
such
as
FORMAT.
COM
and
DISKCOPY.COM
are
external
commands.
You
may
create
external
commands
and
add
them
to
the
system.
Programs
that
you
create
with
most
languages
(including
assembly
language)
are
.exe (executable) files.
When
you
enter
an
external
command,
do
not include
its
file-
name
extension.
29
To Next Page
Loading...
Need help?
General
