Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
Wide character in print... warning in Perl
Answer:
Assume you have a simple script that print out UTF-8 characters in your script.
E.g.
#!/usr/bin/perl
my $foo = "Hello \x{4E2D} \x{570B}\n";
print $foo;
When you run it, it will give out warnings...
Wide character in print at test.pl line 5.
Hello 中 國
To fix for the problem, add the line at the top of your program.
use encoding "utf-8";
Run Perl with useful warnings
Answer:
For good programming habits, it is advised to run Perl using the -w flag so it will print out some useful warnings that might be useful for your program.
E.g.
# perl -e 'print $foo';
The above script shows nothing, but with the -w flag,
# perl -w -e 'print $foo';
Name "main::foo" used only once: possible typo at -e line 1.
Use of uninitialized value $foo in print at -e line 1.
So you can see it is very useful for debugging your program.
In fact, the -w flag is the same as the warnings pragma
use warnings;
Turn on all error reporting in PHP
Answer:
Sometimes, when debugging, it is helpful when you need to enable all PHP errors and make them visible in your application (not in the log), you can put the following line at the top of your script.
<?php
error_reporting(E_ALL);
Counting the number of pair(s) in Perl's hash
Answer:
If you have a Perl's hash variable, e.g. %hash, you can count the total number of hash pair (i.e. key/value) in that variable, like the following.
my $count = scalar keys %hash;
Remove the last character of a string in Perl
Answer:
If you want to remove the last character of a string in Perl, e.g.
abc => ab
You can use the chop() function.
my $string = 'abc';
chop($string);
print $string; # give ab
