Assuming that I have guessed correctly at the structure of your missing example data, this solves the problem.
#!/usr/bin/perl
use strict;
use warnings;
my %institute_department_roll_name_mark_HoHoHoH = (
CIA => {
HUMINT => {
rollno1 => {
Bob => 65,
Adam => 87,
},
rollno2 => {
Dennis => 37,
Arthur => 41,
},
},
SIGINT => {
rollno1 => {
Harry => 87,
Albus => 100,
},
rollno2 => {
M => 70,
Q => 98,
James => 75,
},
},
},
NSA => {
Encryption => {
rollno1 => {
Abel => 13,
Baker => 28,
Charlie => 57,
},
rollno2 => {
Roger => 2,
Fox => 3,
Dog => 2,
},
},
Decryption => {
rollno1 => {
Marin => 62,
Chong => 66,
},
rollno2 => {
Dave => 0,
},
},
},
);
# Create a flattened data structure.
my $h1 = \%institute_department_roll_name_mark_HoHoHoH;
my @institute_department_roll_name_mark_AoH;
while ( my ( $institute, $h2 ) = each %{$h1} ) {
while ( my ( $department, $h3 ) = each %{$h2} ) {
while ( my ( $roll, $h4 ) = each %{$h3} ) {
while ( my ( $name, $mark ) = each %{$h4} ) {
push @institute_department_roll_name_mark_AoH, {
INST => $institute,
DEPT => $department,
ROLL => $roll,
NAME => $name,
MARK => $mark,
};
}
}
}
}
@institute_department_roll_name_mark_AoH = sort {
$b->{MARK} <=> $a->{MARK}
or $a->{INST} cmp $b->{INST}
or $a->{DEPT} cmp $b->{DEPT}
or $a->{ROLL} cmp $b->{ROLL}
or $a->{NAME} cmp $b->{NAME}
} @institute_department_roll_name_mark_AoH;
for my $href (@institute_department_roll_name_mark_AoH) {
printf "%7d\t%-7s\t%-15s\t%-7s\t%s\n",
@{$href}{qw( MARK INST DEPT ROLL NAME )};
}
Output:
100 CIA SIGINT rollno1 Albus
98 CIA SIGINT rollno2 Q
87 CIA HUMINT rollno1 Adam
87 CIA SIGINT rollno1 Harry
75 CIA SIGINT rollno2 James
70 CIA SIGINT rollno2 M
66 NSA Decryption rollno1 Chong
65 CIA HUMINT rollno1 Bob
62 NSA Decryption rollno1 Marin
57 NSA Encryption rollno1 Charlie
41 CIA HUMINT rollno2 Arthur
37 CIA HUMINT rollno2 Dennis
28 NSA Encryption rollno1 Baker
13 NSA Encryption rollno1 Abel
3 NSA Encryption rollno2 Fox
2 NSA Encryption rollno2 Dog
2 NSA Encryption rollno2 Roger
0 NSA Decryption rollno2 Dave
