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 useful for executing a series of commands, their functionality is limited to what is available at the command line which can make them easier to learn.

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.
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";

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