# File:	matchTime.pl
# Title:  Find in a sentence where is time
# any number of blanks is (\s{0,}) 
# \s is blank and {0,} means any number greater or equal to 0
# [0-9] means any char between 0 and 9 (a digit)
# Author:	Mihaela  Malita
$s = "Come today at 12:30PM in my office";	 # find 2:30 PM	
print "Finds time expression in sentence $s.\n";
$s =~ m/[0-9][0-9]:[0-9][0-9](AM|PM)/;  # variable $1 takes the value of the match 
print "result= $&\n"; # prints exact match $&
# same but extra () puts everything in $1
$s =~ m/([0-9][0-9]:[0-9][0-9](AM|PM))/;  # variable $1 takes the value of the match 
print "result= $1 \n"; # prints Time 
# if you which to capture also blanks  
$s = "Come today at 12:30   PM in my office";	 # find 2:30 PM	
$s =~ m/[0-9][0-9]:[0-9][0-9](\s{0,})(AM|PM)/;
print "result= $&\n"; # prints exact match $&= 12:30   PM
$s = "Come today at 5:30 AM in my office";	 # find 2:30 PM	
$s =~ m/([0-9]|[0-9][0-9]):[0-9][0-9]\s(AM|PM)/; # 1 digit or 2 digits for hour,only 1 space,then AM or PM
print "result= $&\n"; # prints exact match $&= 5:30 PM
exit;