Title: Cookies management with Perl

One of the main strengths of the Perl programming language are its powerful text manipulation features. In this assignment, you will put them to use for writing a Perl program that can manage a simplified version of the so-called "brows er cookies" .

These are the specifications for your Perl program:

1. The file with your program must be named cookiemgr.pl

2. The program must be invoked as: cookiemgr.pl cookies_file [options]

The program must check that its first argument exists, is a file and is readable. If not, it must print string:

Error: a valid file must be passed as first argument

to the standard output, and exit. The first argument is compulsory while the following arguments are optional. The arguments are described in the following.

3. File cookies_file can have any arbitrary name. It must be a file of text with the following format:

a. The file consists of an arbitrary number of lines (including, possibly, zero lines).

b. Each line must contain four fields separated by commas.

c. The four fields are: cookie name, cookie value, hostname and expiry date.

d. The first three fields are strings of arbitrary (yet reasonably limited) length; the characters in these strings can be any of: uppercase letters, lowercase letters, decimal digits, the underscore and the dot.

e. The expiry date field is a string of decimal digits in the so-called Unix epoch format.

The following example is the ultimate specification for the format of file cookies_file:

SessionID,029380,xyz.org.au,1385874000ASPX_ANONYMOUS,CjnjrB,xyz.org.au,1356912000 SESSION_COLOUR,red,nosite.com.au,1341014400SESSION_ACTIVE,FALSE,nosite.com.au,1341014400 username001,massimo.piccardi,hello.uts.edu.au,2145830400username012,john.smith,hello.uts.edu.au,2145830400 username013,michael.zhang,hello.uts.edu.au,2145830400

Important note: your program does not need to verify that file cookies_file complies with the format specifications. You can simply assume that the file meets all the specifications given above
4. Your program can be invoked without any options. In this case, it must only print the following string:

Found cookies Example with the example cookies_file given above:

Command line:

cookiemgr.pl cookies_file

Output:

Found 7 cookies

In the case in which file cookies_file is empty, your program must instead only print:

No cookies found

5. Your program can be invoked with option: -h hostname. In this case, it must only print the following string:

Found cookies for host

Example with the example cookies_file given above:

Command line:

cookiemgr.pl cookies_file -h nosite.com.au

Output:

Found 2 cookies for host nosite.com.au

Option -h hostname can only be used once per command line (you can only ask for the cookies of one host at a time). In the case in which file cookies_file contains no cookies for the given hostname, your program must instead only print: No cookies found for host

Example with the example cookies_file given above:

Command line:

cookiemgr.pl cookies_file -h feit.uts.edu.au

Output:

No cookies found for host feit.uts.edu.au

6. Your program can be invoked with option: -d date, where date is entered in dd/mm/yyyy format. In this case, it must only print the following string:

Found cookies expiring before or on

To find the cookies expiring before, or on, the date given in the option, your program must convert this date to the Unix epoch format and compare it with the dates stored in cookies_file. The time of the date is always assumed to be 0 hours, 0 minutes, 0 seconds and the time used is the Coordinated Universal Time (UTC), also often referred to as Greenwich Mean Time (GMT). Perl has a function for converting a GMT time to the Unix epoch time.

Example with the example cookies_file given above:

Command line:

cookiemgr.pl cookies_file -d 31/12/2012

The Unix epoch format for 31/12/2012, midnight, is 1356912000. In file cookies_file there are three dates which are smaller or equal than 1356912000. Therefore, the output must be:

Found 3 cookies expiring before or on 31/12/2012

Option -d date can only be used once per command line (you can only ask for the cookies for a given date at a time). In the case in which file cookies_file contains no cookies expiring before or on the given date, your program must instead only print: No cookies found expiring before or on Example with the example cookies_file given above:

Command line:

cookiemgr.pl cookies_file -d 31/05/2010

The Unix epoch format for 31/05/2010, midnight, is 1275264000. In file cookies_file there are no dates which are smaller or equal than 1275264000. Therefore, the output must be:No cookies found expiring before or on 31/05/2010

7. Your program can be invoked with option: -s. In thi s case, it must only print your name, surname and student ID in a format of your choice.

8. The options cannot be used simultaneously. This means that your program can only be invoked in the following way: 1) with no options; 2) with option -h hostname; 3) with option -d date; 4) with option -s.

9. If your program is invoked with a valid first argument, but any other syntax than what specified above, it must only print the following string to the standard output:

Invalid syntax/options Example:

Command line:

cookiemgr.pl cookies_file UTS.txt -v

Output:

Invalid syntax/options

10. Zip your file cookiemgr.pl into a file named USP__.zip and submit it with the modalities specified above.

Please be reminded that:

• this assignment must be your own work and you should not be helped by anyone to prepare it in any way;

• the submission of the assignment is not compulsory to pass the subject and it only counts for ten marks;

• understanding the assignment specifications is part of the assignment itself and no further instructions will be provided; on the other hand, whatever is not constrained you can implement it according to your own best judgment.