You have to start with the following line for Unix systems to work properly
#!/usr/bin/perl -w
Comments are done with a pound sign
# This is a single line comment
# The same comment symbol is used for multiple lines as well
# (e.g. If you want multiple lines commented out, use the # sign on each line)
Variables are declared loosely using a dollar sign $
All Perl statements are ended with a semicolon ; after the statement
Varaible values (esp. text strings) are quoted (like in HTML)
$TheDB = 'edata.txt';
To check the version of Perl that you have installed (or if it is even installed
at all):
perl -v
If it is installed, you should get something similar to the following (taken from Ubuntu Feisty Fawn):
brian@ubuntulaptop:~/AuthorCode$ perl -v
This is perl, v5.8.8 built for i486-linux-gnu-thread-multi
Copyright 1987-2006, Larry Wall
Perl may be copied only under the terms of either the Artistic License
or the
GNU General Public License, which may be found in the Perl 5 source kit.
Complete documentation for Perl, including FAQ lists, should be found on
this system using "man perl" or "perldoc perl". If you have
access to the
Internet, point your browser at http://www.perl.org/, the Perl Home Page.
brian@ubuntulaptop:~/AuthorCode$
Q1:
-Print (@array[0]); means that I want the first value in the new array (it starts
counting at 0, not 1)
-Sort (@array); will sort the items in the array according to alphabetical order
(e.g. (y, w, x) becomes (w,x,y)
-Unshift (@array, "z"); will unshift the order of the items in the
array, and cause the additional value "Z" to be placed first in the
list
-With the sort command still in place, the values then become (z,w,x,y)
-Without the sort command, the values are (z,y,w,x)
Q2:
What is function of if ($i%2)
(it's the % symbol that I hold in question)
It causes $i to increase from 1 to 16, then increase by 2 ?? until it gets to
24, since $i must be < 25
Q3:
Passing arguments to functions is done using the following syntax:
getpass($arg2)
(get pass is the function, $arg2 is the argument passed to it)
Q4:
-Arrays are declared using @array instead of $array
@ is for array
$ is for scalar values (e.g. 1 value only)
% is for a hash (what's a hash??)
-Sorting is done in alphabetical order, but doing Upper Case first, then lower case