From perlop (boldface added for emphasis):

If what's within the angle brackets is neither a filehandle nor a simple scalar variable containing a filehandle name, typeglob, or typeglob reference, it is interpreted as a filename pattern to be globbed, and either a list of filenames or the next filename in the list is returned, depending on context. This distinction is determined on syntactic grounds alone. That means <$x> is always a readline() from an indirect handle, but <$hash{key}> is always a glob(). That's because $x is a simple scalar variable, but $hash{key} is not--it's a hash element. Even <$x > (note the extra space) is treated as glob("$x "), not readline($x).

Hope that helps,

> perl -MO=Deparse,-p -e 'print "$_\n" for < a >;'

> perl -MO=Deparse,-p -e 'print "$_\n" for <a>;'

a could be an old-style bare-word file-handle, but " a " can't

think

• open a, "<", "filename"

one of the reasons why ppl are encouraged to use lexical filehandles:

• open my $fh, "<", "filename"

From this StackOverflow answer,

• <> means readline(ARGV)
• <IDENTIFIER> means readline(IDENTIFIER)
• <$IDENTIFIER> means readline($IDENTIFIER)
• <...> (anything else) means glob(qq<...>)

<...> (anything else) means glob(qq<...>)
Anything? Except this:

perl -MO=Deparse,-p -e 'print "$_\n" for <<>>'
[download]

print("$_\n") foreach (<<>>);

Perl waits for input:

echo fubar | perl -e 'print "$_\n" for <<>>'
[download]

fubar

Different operator. I also didn't cover <<EOF eventually followed by >, or $x<123 eventually followed by a >, etc.