How to Generate a Random Password

Developing passwords for a large number of users is a less daunting task if a random password generator is utilized. Passwords can include alphanumerical characters, as well as symbols, and be as lengthy as the developer wishes. Randomly generated passwords are typically issued as a default for new users of an application. A Perl script that generates 7 character passwords constructed of randomized symbols, numbers and letters can be used to generate random passwords.

Things You'll Need

• Perl Text editor, e.g. Emacs, Context, Notepad

Instructions

1. Type the "she-bang" line. This is a line of Perl code that lets the interpreter know that what is being called is a Perl script. This line of code goes at the very top of the script.
   #!/usr/bin/perl

2. Assign character array values. To do this, you will need four different arrays for the four character types in the password. The arrays below are set to numbers from 1 to 9, several character symbols, lowercase letters, and uppercase letters.
   @num = (1..9);
   @char = ('@','#','$','%','^','&','*','\(','\)');
   @alph = ('a'..'z');
   @alph_up = ('A'..'Z');

3. Define the random assignment array. This array combines the elements of the character arrays. There must be 7 of them so some character types will occur with more frequency than others. The decision of what extra character types to include is made by the developer.
   @lets = (@alph,@alph_up,@num,@num,@char,@alph,@num1);

4. Assign password variables. In this snippet of code, each character of the password is assigned a randomized value through the "int rand" command which randomizes the items in each array.
   $rand_let1 = $lets[int rand @lets];
   $rand_let2 = $lets[int rand @lets];
   $rand_let3 = $lets[int rand @lets];
   $rand_let4 = $lets[int rand @lets];
   $rand_let5 = $lets[int rand @lets];
   $rand_let6 = $lets[int rand @lets];
   $rand_let7 = $lets[int rand @lets];

5. Program the output. In this program, the output is printed to the Windows shell as an individual password. The following code allows the password to be assembled.
   print "$rand_let1"."$rand_let2"."$rand_let3"."$rand_let4"."$rand_let5".
   "$rand_let6"."$rand_let7\n";
   Save the code as "pass_gen.pl."

6. 

   Execute the program. In the Windows command prompt, go to the directory where the gen_pass.pl file is saved. Once in the directory, type the following to run the program.
   "perl gen_pass.pl"
   You should get a randomized 7 character password as output.

Tips & Warnings

• Make the password as short or as lengthy as you see fit. If you would like to save the passwords you generate to a list in a text file, type open "(PASS,">>pass.txt");" under the she bang line and type "print PASS "$rand_let1"."$rand_let2"."$rand_let3"."$rand_let4"."$rand_let5"."$rand_let6"."$rand_let7\n";" under the first print command. The "pass.txt" text file will get generated and saved automatically in the same directory as your program.

References

• Christiansen, T. & Torkington, N. (2003). Perl Cookbook, 2nd Edition. O'Reilly Media, Inc.(Sec.2.6).