Perl Module File::Modified Files parameter

Question

The documentation of File::Modified says:

my $d = File::Modified->new(files=>['Import.cfg','Export.cfg']);

The files parameter looks to me as being an array.

Why can I not directly hand over an array?

my $d = File::Modified->new(files=>@array);

This creates a runtime error.

Does this answer your question? Passing array to subroutine Perl — tobyink
– tobyink, Commented Aug 30, 2023 at 12:58
files=>@array would results in files=>'Import.cfg', 'Export.cfg'=>undef — ikegami
– ikegami, Commented Aug 30, 2023 at 13:39

toolic · Accepted Answer · 2023-08-30 13:15:39Z

3

The files parameter is not an array; it is a reference to an array.
The File::Modified POD says:

Files, which takes an array reference to the filenames to watch.

This is why you can not simply pass an array variable like that.

The square brackets create a reference to an array, which is different from an array.

As the perlref document shows, one way to take a reference to an array is to use the backslash:

my $d = File::Modified->new(files => \@array);

answered Aug 30, 2023 at 13:02

toolic

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