There are several things that will keep your code from compiling, but I take it you want big picture comments/criticism so here goes:

This looks like you are mixing two concepts, splitting a string and match/capture on a string. Split's first argument is a pattern that matches what separates the things you want in the string, and it returns those things. You might want this:

That'll put the '777666555' field into $key, and stuff all the other fields into the array. As far as getting that array into a hash (making the hash have multiple values), I'd check out perldoc perldsc. It is a good tutorial for Perl's compound data structures.

But, like I said, there are some wonky things with your example code that I'd clean up before doing anything else. (Another sort of mixed concept thing going on is that you try to dump INPUT into an array the line before you open it, and then later try to iterate over INPUT anyway.) You can fix several problems (like the missing greater than on while(<INPUT>) just by trying to run the above, Perl will choke, die, and give you pretty verbose error messages.

And don't forget:

You don't need this variable in file scope

You haven't opened the INPUT filehandle yet so that statement makes no sense.

You should include the $! variable in your error statement so you know why it failed.   Why not just let die print out the error message?

You are missing the closing  > delimiter.

Because %hash is declared as a lexical variable inside the while loop it is only visible inside the while loop.

split removes whatever the pattern matches and returns a list of everything that didn't match so it looks like nothing will be returned.   Your character class [a-z|A-Z] includes the '|' character but it doesn't look like your data contains that character.   What you probably want is something like:

while ( <INPUT> ) {
   my ( $key, @values ) = split ' ', $_, -1;
   push @{ $config{ $key } }, @values;
}

@studentList = @{$config{"studentList"}};

It doesn't appear that your data has a "studentList" key, it looks like all the keys are nine digit numbers.

You can't use %hash here because it is lexically scoped to the while loop.

Please use code tags <c> code goes here </c> or <code> code goes here </code>

I did use code tags.    But thanks for asking.    :-)

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my $sdata = 'student.data';
my %students;
open my $infile, '<', $sdata or die "Cannot open $sdata:$!\n";

while (my $line = <$infile>) {
    chomp($line);
    my ($id,$name,$f3,$f4) = $line =~ m/^(\d+)\s(.*)\s(..)\s(..)$/;
    $students{$name}{id} = $id;
    $students{$name}{f3} = $f3;
    $students{$name}{f4} = $f4;
}

close $infile;

print Dumper(\%students);
[download]

$VAR1 = {
          'Smith Tom' => {
                           'f3' => 'RM',
                           'id' => '777666555',
                           'f4' => 'So'
                         },
          'Johnson Lee' => {
                             'f3' => 'IE',
                             'id' => '555444333',
                             'f4' => 'Sr'
                           },
          'Jones Mary' => {
                            'f3' => 'SD',
                            'id' => '111222333',
                            'f4' => 'Fr'
                          }
        };
[download]

for my $student (sort {$students{$a}{id} <=> $students{$b}{id}} keys %
+students) {
    print "$student => $students{$student}{id}\n";
}
[download]