Finding Exact Matches in Text Strings

---

Verifying Date Formats in Perl

The Perl script in Listing C.23 uses an array to store the number of days in each month (including leap years) and the Perl split function in order to validate a date string.

Listing C.23 verifyDate1.pl.

my($date)  = "11/25/2003"; my($month) = 0; my($day)   = 0; my($year)  = 0; my(@daysInMonth) = (0,31,28,31,30,31,30,31,31,30,31,30,31); ($month, $day, $year) = split(/\//, $date); if( $year % 4 == 0 ) {    if( ($year % 100 == 0) && ($year % 400 != 0) )    {       $daysInMonth[1] = 29;    } } if( $year >= 1 ) {    if( ($day <= $daysInMonth[$month]) && ($day >= 1) )    {       if( ($month > 0) && ($month <= 12) )        {          print "Date $date is valid\n";       }       else       {          print "Month $month is out of range\n";       }    }    else    {       print "Day $day is out of range\n";    } } else {    print "Year $year must be at least 1\n"; }

Remarks

You can invoke the Perl script verifyDate1.pl from the command line as follows,

perl -w verifyDate1.pl

and the output will be as follows:

Date 11/25/2003 is valid

---