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 canmanage a simplified version of the so-called "browser 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 followingformat:
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; thecharacters 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 epochformat.
The following example is the ultimate specification for the format of file cookies_file:
SessionID,029380,xyz.org.au,1385874000
ASPX_ANONYMOUS,CjnjrB,xyz.org.au,1356912000
SESSION_COLOUR,red,nosite.com.au,1341014400
SESSION_ACTIVE,FALSE,nosite.com.au,1341014400
username001,massimo.piccardi,hello.uts.edu.au,2145830400
username012,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_filecomplies with the format specifications. You can simply assume that the file meets all the specifications given abov.
Your program can be invoked without any options. In this case, it must only print thefollowing string:
Found cookies
Example with the example cookies_filegiven above:
Command line:
cookiemgr.pl cookies_file
Output:
Found 7 cookies
In the case in which file cookies_fileis 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 thefollowing string:
Found cookies for host
Example with the example cookies_filegiven 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 thecookies of one host at a time).
In the case in which file cookies_filecontains no cookies for the given hostname, your program must instead only print:
No cookies found for host
Example with the example cookies_filegiven above:
Command line:
cookiemgr.pl cookies_file-h feit.uts.edu.au
Output:
No cookies found for host feit.uts.edu.au
Your program can be invoked with option: -d date, where date is entered in dd/mm/yyyyformat. In this case, it must only print the following string:
Found cookies expiring before or on
format>
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 set to be midnight (i.e. 0 hours, 0 minutes, 0 seconds). Perl has functions for converting a date to the Unix epoch format.
Example with the example cookies_filegiven 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_filethereare 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_filecontains 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_filegiven above:
Command line:
cookiemgr.pl cookies_file-u 31/05/2010
The Unix epoch format for 31/05/2010, midnight, is 1275264000. In file cookies_filethere 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
Your program can be invoked with option: -s. In this case, it must only print your name,surname and student ID in a format of your choice.
The options cannot be used simultaneously. This means that your program can only beinvoked in the following way: 1) with no options; 2) with option -u username; 3) withoption -d date; 4) with option -s.
If your program is invoked with a valid first argument, but any other syntax than whatspecified above, it must only print the following string to the standard output:
Invalid syntax/options
Example:
Command line:
cookiemgr.pl cookies_fileUTS.txt -v
Output:
Invalid syntax/options