[0-9]+ means at least one digit in range 0-9.
If there is no digit, the string won't match.
You want [0-9]* instead.
--Octavian
----- Original Message -----
From: Rick T
To: Perl Beginners
Sent: Friday, June 01, 2018 11:54 PM
Subject: difficulty with matching
This is a newbie question, I’m sure. But I get perplexed easily!
The follow code segment expects to receive a $student_id consisting of a
surname followed by a hyphen followed by a number. The die is for testing what
I’m doing.
If I feed it 'jones-123’ it dies with ‘jones, - , 123’ as I expected. But if
I feed it ‘jones-‘ omitting the number on the end, it dies with no matches at
all (or blanks): ‘ , , ‘ and I cannot figure out why it does not die with
‘jones, -, ' and would appreciate an explanation. Many thanks!
$student_id = lc $student_info_hash{student_id}; # Impose lower case
$student_id =~ s/\s//xmsg; # Remove whitespace
$student_id =~
m{
\A([a-z]+) # match and capture leading alphabetics
(-) # hyphen to separate surname from student number
([0-9]+\z) # match and capture trailing digits
}xms; # Perl Best Practices
$student_surname = $1;
my $hyphen = $2;
$student_number = $3;
die "$student_surname, $hyphen, $student_number”;
Rick Triplett
