Both are good, but if you concatenate files and want to make your code portable, I recommend the File::Spec::Functions module.

Something like this: 
use File::Spec::Functions qw(catfile);
my $filename = catfile($file_dir, q{filename1.log.} . $today_date);

[download]

Back on the topic. The following codes are equivalent:
1. $this . q{/} . $that
2. join(q{/}, $this, $that)
3. "$this/$hat"
4. do{local $"=q{/}; "@{[$this, $that]}"}
5. sprintf('%s/%s', $this, $that)

Most used are: 1, 2, 3.

In reply to Re: string concatenation, which way is better? by trizen
in thread string concatenation, which way is better? by faneesh

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