The namespace Local:: has been reserved for just this purpose. No module that starts with that prefix will be accepted to CPAN or the core. Alternatively, you can use an underscore in the top-level name (like My_Corp::Session or just My_Session). All categories with an underscore have also been reserved. (This is mentioned in perlmodlib, under … Read more
The short answer is that my marks a variable as private in a lexical scope, and local marks a variable as private in a dynamic scope. It’s easier to understand my, since that creates a local variable in the usual sense. There is a new variable created and it’s accessible only within the enclosing lexical … Read more
Test whether something exists at given path using the -e file-test operator. print “$base_path exists!\n” if -e $base_path; However, this test is probably broader than you intend. The code above will generate output if a plain file exists at that path, but it will also fire for a directory, a named pipe, a symlink, or … Read more
From Perlfaq8: You’re confusing the purpose of system() and backticks (“). system() runs a command and returns exit status information (as a 16 bit value: the low 7 bits are the signal the process died from, if any, and the high 8 bits are the actual exit value). Backticks (“) run a command and return … Read more
Use a module. Check out perldoc perlmod and Exporter. In file Foo.pm package Foo; use strict; use warnings; use Exporter; our @ISA= qw( Exporter ); # these CAN be exported. our @EXPORT_OK = qw( export_me export_me_too ); # these are exported by default. our @EXPORT = qw( export_me ); sub export_me { # stuff } … Read more
pp can create an executable that includes perl and your script (and any module dependencies), but it will be specific to your architecture, so you couldn’t run it on both Windows and linux for instance. From its doc: To make a stand-alone executable, suitable for running on a machine that doesn’t have perl installed: % … Read more
The statement $name = <STDIN>; reads from standard input and includes the terminating newline character “\n“. Remove this character using the chomp function: print “What is your name?\n”; $name = <STDIN>; chomp($name); if ($name eq “Jon”) { print “We have met before!\n”; } else { print “We have not met before.\n”; }
… SSL3_CHECK_CERT_AND_ALGORITHM:dh key too small I have looked in to using LWP and raw Net:SSLeay, but the problem seems to be in the underlying OpenSSL libs. While it is caused by changes to OpenSSL the problem is actually at the server side. The server is using a weak DH key within the key exchange and … Read more
When you installed the module, did you watch the output? Where did it say it installed the module? Look in lib. Do you see the next directory you expect? Look in ~/lib to see where eveything ended up to verify that you have the right directory name in your use lib statement: % find ~/lib … Read more
Do not use the encoding pragma. It’s broken. (Juerd Waalboer gave a great talk where he mentioned this at YAPC::EU 2k8.) It does at least two things at once that do not belong together: It specifies an encoding for your source file. It specifies an encoding for your file input/output. And to add injury to … Read more