my @shifts = qw( 5:00am 5:30am 6:00am 6:30am 7:00am 7:30am 8:00am 8:30am 9:00am );


print " enter time to schedul \n";

read $time;

open my $fh, '+<', 'students.dat' or die "open failed: $!";
flock $fh, LOCK_EX or die "flock failed: $!";

my $found = 0;
while (<$fh>) {

   $found = 1 if index($_, $time)== 0;
}

print $fh $locationNumber ,"\t" , $studentNumber ,"\t" , $time ,"\n" unless $found;

close $fh;


}


students.dat
------------
name     Number  time
Sam      04      5:00am
Eddi     23      5:30am