# wages.pl - An example program to ulustrate some of
#            the features of Perl
#   Input:   A file of lines of employee data, where
#            each line has name, age, department
#            code, salary
#   Output:  1.  The names of all employees whose
#                names end with "son"
#            2.  Percentage of employees under 40
#                years old
#            3.  Average salary of employees under
#                40 years old
#            4.  An alphabetical list of employees
#                who are under 40 years old and who
#                have salaries more than $40,000
#>>> Open the data file and display a head for
#    employees whose names end in 'son'
open(EMPLOYEES, "employees.txt") 
               || die "Can't open employees $!";
print "Names that end in 'son'\n\n";

#>>> Loop to read and process the employee data
while (<EMPLOYEES>)  {
  #>>> Increment the number of employees and chop
  #    off the newline
  $total_employees++;
  chomp;


  #>>> Split the input line into its four parts
  ($name, $age, $dept, $salary) = split(/,/);
  #>>> If the name ends in 'son', print the name
  if ($name =~ /(son.?)$/) {
    print "$name found $1\n";
  }

  #>>> If the employee is under 40, count him or her
  #    and add his or her salary to the sum of such
  #    salaries
  if ($age < 40) {
    $under_40++;
    $salary_sum += $salary;

    #>>> If the salary is over $40,000, add the
    #    person and his or her salary to the hash of
    #    such people
    if ($salary > 40000)  {
      $sublist{$name} = $salary;
    }
  }
}
#>>> If there was at least one employee, continue
if ($total_employees > 0)  {

  #>>> If there was at least one under 40, continue
  if ($under_40 > 0)  {
    #>>> Compute and display the % of employees
    #    under 40 and their average salaries
    $percent = 100 * $under_40 / $total_employees;
    print "\nPercent of employees under 40 is: ",
          " $percent \n";
    $avg = $salary_sum / $under_40;
    print "Average salary of employees under 40 ",
          "is: $avg \n";
    #>>> If there was at least one under 40 who
    #    earned salary > 40,000, continue
    if (keys(%sublist))  {
      #>>> Sort and display the names of the
      #    employees under 40 with salaries > 40,000
      print "Sorted list of employees under 40",
            " with salaries > \$40,000 \n";
      @sorted_names = sort (keys(%sublist));
      print "\nName \t\t Salary \n";
      foreach  $name (@sorted_names)  {
        print "$name \t \$$sublist{$name} \n";
      }
    }
    else {
      print "There were no employees under 40 ",
      print "who earned over \$40,000 \n";
    }  #>> of if (keys(%sublist))
  }
  else  {
    print "There were no employees under 40 \n";
  } #>>> of if ($under_40 > 0)
}
else {
  print "There were no employees\n";
} #>> of if ($total_employees > 0)