Chapter 2 Operating Systems 47
The earlier version of
cmd.exe
was
command.
com. The
command.com
program is considered
legacy by modern operating systems. Another
name for
command.com
and
cmd.exe
is command
interpreter. The command interpreter contains a
set of programs that are activated by text entered
at the command prompt. These commands
are known as internal commands because the
required software to run them resides inside
command.com
and cmd.exe. Following are
examples of several common internal commands.
Command System Response
copy Copies a fi le or group of fi les from one
location to another location.
date Displays the date.
del Deletes a fi le.
dir Displays a list of fi les, directories, and
subdirectories.
rename Changes the name of a fi le.
time Displays the time.
ver Displays the software version running
on the computer.
The command interpreter also uses several
external commands. These are individual,
executable files found in addition to the internal
commands. The external commands can be
viewed in the Windows directory structure,
usually under
C:/Windows/System32
for
32-bit systems and
C:/Windows/sysWOW64
for
64-bit systems. The external commands in
modern operating systems are identified as an
“Application” but use the
.exe
file extension.
Following are several examples of common
external commands.
Command System Response
chkdsk Checks the condition of a disk and
displays a report.
edit Starts a text editor program similar to
a word processor.
format Prepares a disk for storing data.
print Prints a text fi le to a printer.
Microsoft refers to the program that produces
the command line as the command prompt. The
Figure 2-12. An error
message displays
when a user enters
a file name with a
restricted character.