How Do You Parse a Line After Each Character?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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RE: How Do You Parse a Line After Each Character? by mikfire (Deacon) on Jul 11, 2000 at 21:57 UTC
Hmm. First let me warn that perl doesn't like doing playing with characters like this. Second, $variable will not work - you are evaluating your split in scalar context, meaning it will return the number of characters in the line which is better done by length(). `@letters = split //;` [download] will work though. Mik Firestone ( perlus bigotus maximus )	[reply] [d/l]
Re: How Do You Parse a Line After Each Character? by jjhorner (Hermit) on Jul 11, 2000 at 22:44 UTC
From the Perl Cookbook, 1.5: `# break into individual characters my @characters = split(//); # or if you want ASCII values my @characters = unpack("C"); # of if you wish to use a loop while (/(.)/g) { # . is never a newline # do something with $1 }` [download] For a real world example, also from the Perl Cookbook (modified slightly): `my %seen = (); my $string = "J. J. Horner is so cool!"; foreach my $byte (split //, $string) { $seen{$byte}++; } print "unique chars are: ", sort(keys %seen), "\n";` [download] Which yeilds: unique chars are: !.HJceilnors* J. J. Horner Linux, Perl, Apache, Stronghold, Unix jhorner@knoxlug.org http://www.knoxlug.org/	[reply] [d/l] [select]
RE: How Do You Parse a Line After Each Character? by Adam (Vicar) on Jul 11, 2000 at 22:05 UTC
Why are you comparing lines char by char? I mean, what's the purpose? Are you sorting the lines? (use `cmp`) Are you looking for something? (use a regular expression) I'm not sure I can think of a reason to split a string into its member chars, except maybe to scramble it, or find usage stats for various chars (also done better with a regex). Share your problem statement with us, and maybe we can cook a better solution. Oh, and mikfire is right about your misuse of split. It returns an array, which in scalar context is a size.	[reply]