Yes, Google is notoriously difficult for looking up punctuation and, unfortunately, Perl does seem to be mostly made up of punctuation 🙂 The command line switches are all detailed in perlrun (available from the command line by calling perldoc perlrun). Going into the options briefly, one-by-one: -p: Places a printing loop around your command so … Read more
use utf8; does not enable Unicode output – it enables you to type Unicode in your program. Add this to the program, before your print() statement: binmode(STDOUT, “:utf8”); See if that helps. That should make STDOUT output in UTF-8 instead of ordinary ASCII.
I would do it like this: my $file = “index.html”; my $document = do { local $/ = undef; open my $fh, “<“, $file or die “could not open $file: $!”; <$fh>; }; Note the use of the three-argument version of open. It is much safer than the old two- (or one-) argument versions. Also … Read more
To find out if a string contains substring you can use the index function: if (index($str, $substr) != -1) { print “$str contains $substr\n”; } It will return the position of the first occurrence of $substr in $str, or -1 if the substring is not found.
If your scripts are for your use only, you can install grep from homebrew-core using brew: brew install grep Then it’s available as ggrep (GNU grep). it doesn’t replaces the system grep (you need to put the installed grep before the system one on the PATH). The version installed by brew includes the -P option, … Read more
What context/language? Some languages use / as the pattern delimiter, so yes, you need to escape it, depending on which language/context. You escape it by putting a backward slash in front of it: \/ For some languages (like PHP) you can use other characters as the delimiter and therefore you don’t need to escape it. … Read more
POD is the official way to do multi line comments in Perl, see Multi-line comments in perl code and Better ways to make multi-line comments in Perl for more detail. From faq.perl.org[perlfaq7] How can I comment out a large block of Perl code? The quick-and-dirty way to comment out more than one line of Perl … Read more
Depends on what you want to do. If you want to use the two arguments as input files, you can just pass them in and then use <> to read their contents. If they have a different meaning, you can use GetOpt::Std and GetOpt::Long to process them easily. GetOpt::Std supports only single-character switches and GetOpt::Long … Read more
The flip-flop operator is useful for skipping the first iteration when looping through the records (usually lines) returned by a file handle, without using a flag variable: while(<$fh>) { next if 1..1; # skip first record … } Run perldoc perlop and search for “flip-flop” for more information and examples.
An alternative method to using upgrade from the default CPAN shell is to use cpanminus and cpan-outdated. These are so easy and nimble to use that I hardly ever go back to CPAN shell. To upgrade all of your modules in one go, the command is: cpan-outdated -p | cpanm I recommend you install cpanminus … Read more