Question

I have a small program:

#!/user/bin/perl

use strict;
system ("clear");
my($option, $path);

do
{
    print "\tEnter the number of your chosen option:\n";    
    print "\n";
    print "\tOption\t\tCommand\n";
    print "\t======\t\t=======\n";
    print "\t1\t\tDate\n";
    print "\t2\t\tDirectory Listing\n";
    print "\t3\t\tCalendar\n";
    print "\t4\t\tVi Editor\n";
    print "\t5\t\tCalculator\n";
    print "\t6\t\tExit\n\n";
    chomp($option=<STDIN>);

    SWITCH:
    {
        ($option =="1") and do
        {
            system(date);           
            last;
        };

        ($option =="2") and do
        {
            print "Enter the path:"; ############################
            chomp($path=<STDIN>);    #This is giving me an error#
            system(ls $path);        ############################
            last;
        };  

        ($option =="3") and do
        {
            system(cal);
            last;
        };

        ($option =="4") and do
        {
            system(vi);
            last;
        };

        ($option =="5") and do
        {
            system(bc);
            last;
        };      
    }   
}while ($option!=6);

print "Goodbye!\n";
sleep 2;

First question: Can anyone help me how to write the proper command to create a directory listing in case 2.

Second Question: Why do I get a loop if I use

$date = `date`;
print "$date"; 

instead of

system(date);

Answer 1

You should be able to solve a lot of your problems by remembering to put quotes around literal arguments to system():

system("date");
system("ls $path");

and the same for most other places you call system() (your first call to system("clear") is correct).

It is a quirk of Perl that calling something like system(cal) works at all, because the unquoted cal is treated as a “bareword” by Perl, which happens to be roughly equivalent to a string when passed to a function such as system(). Relying on this behaviour would be terribly bad practice, and so you should always quote literal strings.