Reference no: EM13362576
Scripting Language Programming, Assignment - Perl
General Requirements
? Your coding style should conform to general Perl coding conventions. Your scripts should be clean, neat, and well-formatted (e.g. indention). Identifiers should also be properly named.
? Your scripts should be well-documented by using POD so users can easily understand your scripts and their usage by exporting POD as HTML, plain text or LaTeX.
? You should always properly validate data inputs (including command-line arguments) and display user-friendly error messages where applicable. For example, if a script is expecting only one argument which specifies a file, you should validate:
ü There is only one command line argument (or you should display the 'usage');
ü The specified argument is a file and is accessible.
Depending on what the script does, you should also make other reasonable validations, e.g., whether a specified directory is valid and accessible.
? If a standard output format is not specified, you are free to make your own assumptions so long as your output displays all required information and is in a neat and user-friendly format.
? Any standard Perl modules shipped with Perl 5.10 may be used. However, you should not use any module which is not available on RMIT CSIT Core Teaching Linux servers.
? If you fail to meet the aforementioned general requirements, you may lose up to 25% of marks available in each part of this assignment.
? You must attempt each part of this assignment progressively. For example, if you attempt Part D without first completing Part C, you will not get any marks for Part D.
Part A: Perl Script Analyser (PartA.pl)
Write a Perl script to analyse another Perl script specified as the first command-line argument.
As part of pre-analysis validations, your script should check if the specified script file:
- ? has an acceptable file extension (defined below); and
- ? exists; and
- ? is a readable text file; and
- ? is not empty.
Acceptable file extensions are (case sensitive):
Your script should display the following error message and quit gracefully if the specified file failed any one (or more) of the pre-analysis validations:
[user@csitprdap01 ~]$ ./PartA.pl /aaa/bbb/ccc/invalid_script.pl
Error: unable to analyse the specified file.
[user@csitprdap01 ~]$
It is important that you display the exact same error message as your assignment submission may be assessed by an automated marking process.
Once a script file passed the pre-analysis validation, your script should perform the following tasks in order:
? Display the number of lines, words, and characters in the file based on the output of an external Linux command of your choice, e.g. wc;
? Identify the keywords in the script, and display them in the order as they first appeared in the file. If a keyword appeared multiple times in the script, only the first instance should be displayed. If there are more than 15 unique keywords in the file, display the first 15 keywords only;
? Identify the strings in the script, and display them in the order as they appeared in the file. If there are more than 10 strings in the file, display the first 10 strings only;
? Identify the comments in the script, and display them in the order as they appeared in the file. If there are more than 5 comments in the file, display the first 5 comments only.
For the purpose of this assignment:
? a keyword is a Perl function keyword, a Perl syntax keyword or a File Handles keyword listed on https://learn.perl.org/docs/keywords.html;
? a string always have single quotes or double quotes around them;
? a comment is the text from a # character until the end of the line, unless the # character is inside a string or a regular expression.
For the purpose of Part A only, we assume:
? keywords appeared in strings and comments are still considered keywords;
? a string is always on the same line, i.e. you do not need to consider multi-line strings;
? # characters do not appear inside strings or regular expressions;
? single or double quoted strings do not appear in comments.
To demonstrate the output format, we use the following sample script file hello.pl:
#!/usr/bin/env perl
use strict;
use warnings;
# assign variable
my $string = 'Hello World!';
# display value
print "$string\n";
The following output from PartA.pl is expected:
[user@csitprdap01 ~]$ ./PartA.pl /home/el2/eXXXXX/scripts/hello.pl
File: hello.pl
Lines: 8
Words: 19
Chars: 129
[Keywords]
use
my
print
[Strings]
'Hello World'
"$string\n"
[Comments]
# assign variable
# display value
[user@csitprdap01 ~]$
It is important that you display the results in the exact same sequence and format as your assignment submission may be assessed by an automated marking process.
This sample script and the expected output will be published in the Blackboard so you can compare if your script is producing an exact identical outcome. Please note this is only for the purpose of hecking output format. To verify if you have implemented the script correctly, you are expected to create more complex test cases yourself.
Part B: Improved Perl Script Analyser (PartB.pl)
Based on your PartA.pl, create a new script PartB.pl.
This new script should perform the same tasks as Part A but WITHOUT using any external command. It is also important to note that the assumptions (in the last paragraph on Page 2) for Part A is no longer valid in Part B. Therefore, in Part B:
? keywords appeared in strings and comments are not considered keywords;
? strings may appear on multiple lines, but they always have single quotes or double quotes around them;
? # characters may appear inside strings or regular expressions;
? single or double quoted strings may appear in comments.
Part C: Advanced Perl Script Analyser (PartC.pl)
Based on your PartB.pl, create a new script PartC.pl.
In addition to the existing features of Part B, you should also identify the numbers in the script using Regular Expressions, and display them in the order as they appeared in the file. If there are more than 10 numbers in the file, display the first 10 numbers only. The identified numbers should be displayed after the keywords section but before the strings section.
For the purpose of this assignment:
? a number is a Perl numeric literal in any of the floating point or integer formats specified on https://perldoc.perl.org/perldata.html#Scalar-value-constructors except those within strings or comments.
A sample script and the expected output for Part C will be published in the Blackboard.
Part D: Perl Script Syntax Highlighter (PartD.pl)
PartD.pl accepts two command line arguments, the Perl script to be syntax highlighted, and then an HTML output filename (with the file extension of either .htm or .html). The script should not produce any output to the screen unless there is an error. If the output file already exists, it will be overwritten.
The title of the generated HTML file should be the file name of the specified script.
The following HTML colour codes should be used to syntax highlight the Perl script in the HTML output:
? Keywords - darkred
? Numbers - darkcyan
? Strings - royalblue
? Comments - darkgreen
To maintain the format and readability, the entire script should be wrapped within a pair of HTML <pre> tags.