diff --git a/perl/wiki b/perl/wiki
index 6311901..c35fe40 100644
--- a/perl/wiki
+++ b/perl/wiki
@@ -806,4 +806,170 @@
     Value of 1 2 3 is : 123
     Type of reference is : HASH
     Value of %var is : key220key110
-    Value of %var is : key110
\ No newline at end of file
+    Value of %var is : key110
+
+
+-> Passing Hashes to subroutine and function pointer:
+    (Reference to function)
+
+    For ex:
+
+    @cardG1CPUarch = ('csc01', 'mips', 'xcc360g', 'ppc', 'cef4c', 'ppc');
+
+    print "==== Passing hashes to subroutines ======\n";
+    #Function definition
+    sub PrintHash{
+        my (%hash) = @_;
+
+        foreach my $key ( keys %hash ){
+            my $value = $hash{$key};
+            print "$key : $value\n";
+        }
+    }
+
+    #Function definition
+    sub PrintRefHash{
+        my ($hashref) = @_;
+
+        foreach my $key (sort keys %$hashref){
+            my $value = $hashref->{$key};
+            print "$key : $value\n";
+        };
+    }
+
+
+    print "\n==========Calling using Reference of Subroutines===\n\n";
+    $pHashRef = \&PrintHash;
+    &$pHashRef(%cardG1CPUarch);
+    print "\n=========Calling using Reference of Hash========\n\n";
+    PrintRefHash(\%cardG1CPUarch);
+
+
+    Output:
+
+    ======== Passing hashes to subroutines ==========
+
+    =====Calling using Reference of Subroutines ========
+
+    cef4c : ppc
+    xcc360g : ppc
+    csc01 : mips
+
+    ====Calling using Reference of Hash======
+
+    cef4c : ppc
+    xcc360g : ppc
+    csc01 : mips
+
+
+-> File Handling in Perl:
+
+    For ex:
+
+    print "\n\n======File Handling in Perl======\n\n";
+    #<FILEHANDLE> operator. In a scalar context, it returns a single
+    #line from the filehandle.
+
+    #Open file to read
+    open(DATA1, "<file1.txt") or die "Can't open data";
+    #Open new file to write
+    open(DATA2, ">file2.txt");
+    # Copy data from one file to another.
+    while(<DATA1>){
+        print DATA2 $_;
+    }
+
+    close(DATA1);
+    close(DATA2);
+
+    #Renaming files
+    rename ("/usr/test/file1.txt", "/usr/test/file1_renamed.txt");
+    #Deleting existing file
+    unlink("/usr/test/file2.txt");
+
+-> REGEX:
+
+    print "\n\n=====REGEX======\n\n";
+    #\(^[a-zA-Z0-9]+\)\. \([a-z]+\)
+    #Ex: SomeDocument1.docx
+
+    #$bar = "This is foo and again foo";
+
+    $bar = "This is foo and again";
+    if ($bar =~ /foo/){
+        print "First time is matching\n";
+    }
+    else{
+        print "First time is not matching\n";
+    }
+
+    $bar = "foo";
+    if ( $bar =~ /foo/ ){
+        print "Second time is matching\n";
+    }
+    else{
+        print "Second time is not matching\n";
+    }
+
+    $date = '03/26/2018';
+    $date =~ s#(\d+)/(\d+)/(\d+)#$3/$1/$2#;
+    print "$date\n";
+
+    $string = "The time is: 11:01:22 on 9/12/01";
+    $string =~/:\s+/g;
+    ($time) = ($string =~ /\G(\d+:\d+:\d+)/);
+    $string =~ /.+\s+/g;
+    ($date) = ($string =~ m{\G(\d+/\d+/\d+)});
+    print "Time: $time, Date: $date\n";
+
+    #implicit case of $_
+    foreach ('csc01', 'cef5', 'xcc369g'){
+        #print $_;
+        print;
+        print "\n";
+    }
+    
+
+    Output:
+
+    ====== REGEX ======
+
+    First time is matching
+    Second time is matching
+    2018/03/26
+    Time: 11:01:22, Date: 9/12/01
+    csc01
+    cef5
+    xcc360g
+
+
+-> Operators in Perl:
+
+    • Bit wise operators: &, | , ^ , <<, >> and ~ (one’s complement),
+    • Logical operators : &&, || , ‘and’, ‘or’ (difference && || have higher precedence)
+    and ‘not’ .
+    • Quoting operators : q{}(single quote Ex: q{abc} = ‘abc’). qq{}(double quotes Ex
+    qq{abc} = “abc”). qx{} (invert quotes, Ex: qx{abc} = `abc` ).
+    • Other Operators :
+    ‘.’(dot) : concatenation operator, Ex: $a . $b
+    ‘..’(range) : range operator , Ex: (1..10)
+    ++/-- : similar to other programming language.
+    -> : dereferencing operator
+    ‘x’ : repetition operator , Ex ( ‘-’ x 4 ) = ----
+
+    • Arithmetic Operators : Similar to other programming languages. Ex : +,-,/,*,%,
+    and ** (exponent operator)
+    • Numeric Equality Operators : ==, !=, >,<, <=, >= and $a <> $b will return -1,0
+    or 1 depending upon left is lesser, equal to or greater than compared to right
+    side value.
+    • String Equality Operators : eq, ne , gt, lt, le, ge, cmp (returns -1,0,1) operators
+    checks string wise .
+    • Short hand operators : Similar to other programming languages. Derived from
+    arithmetic operators.
+
+    • @ARGV : The array containing the command-line arguments intended for the
+    script.
+    • @INC : The array containing the list of places to look for Perl scripts to be
+    evaluated by the do, require, or use constructs.
+
+