Command language

Sometimes referred to as a command script, a command language is a language used for executing a series of commands that would otherwise be executed at the prompt. A good example of a command language is Microsoft Windows batch files. Although command languages are great for executing a series of commands, command languages can be limited when compared to other programming and scripting languages because they offer little more than what is available at the command line. However, because of the lack of options, command languages are much easier to learn for anyone familiar with the command line and do not require the files to be compiled before they are ran.

Below is a basic example of a Microsoft Windows batch file that deletes all the files in the Windows temp directory.

REM Delete Windows temp files.
echo Deleting Windows temp files.
cd\window\temp
del *.* /q

Below is a basic example of a Perl script that could be run in Microsoft Windows that performs a similar task to the above batch file example, but with some more sophistication. In this example, this script not only deletes the files, but creates a log containing information about each file deleted.

# Delete Windows files and log results into log.txt
my (@files, $files);
my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst, $timeoffset);
($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) = localtime;
$year = $year + 1900;

@files = `dir /b c:\windows\temp`;

open(mylog, ">>log.txt") || print "ERROR: $!";
foreach $files (@files) {
$files =~ s/\n//g;
system("del c\:\\windows\\temp\\$files /q");
print "Deleting $files at $hour:$min:$sec on $mon/$mday/$year\n";
print mylog "Deleting $files at $hour:$min:$sec on $mon/$mday/$year\n";
}
close(mylog);

Advantages of command languages

  • Very easy for all types of users to write.
  • Do not require the files to be compiled.
  • Easy to modify and make additional commands.
  • Very small files.
  • Do not require any additional programs or files that are not already found on the operating system.

Disadvantages of command languages

  • Can be limited when comparing with other programming languages or scripting languages.
  • May not execute as fast as other languages or compiled programs.
  • Some command languages often offer little more than using the commands available for the operating system used.

In conclusion, scripts, and command languages are very similar; however, scripts or programs offer the user the ability to perform much more than just commands that would otherwise be executed at the prompt.

Also see: Command, Language, Programming terms, Script