Re: Clash between IO layers and "in memory" files?

Similar behavior when you try to auto-open a string ref via @ARGV

my $header_line = "Prepend this\n";
unshift @ARGV, \ $header_line;
print while <>;
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results in

Can't open SCALAR(0x816411c): No such file or directory at ...
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Anno

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Re^2: Clash between IO layers and "in memory" files? by blazar (Canon) on Mar 29, 2007 at 12:38 UTC
Similar behavior when you try to auto-open a string ref via `@ARGV` Well, I had never thought of that and never seen it documented, although it would certainly be useful a feature to have. But it is somewhat annoying that e.g. `'<'` works and `'<:raw'` doesn't. perldoc -f open, now that I notice, only says: `Since v5.8.0, perl has built using PerlIO by default. Unless you've changed this (i.e. Configure -Uuseperlio), you can open file handles to "in memory" files held in Perl scalars via: open($fh, '>', \$variable) \|\| ..` [download] There's another example later (and no other ones) again with `'>'`, but the technique also works in read mode and, now that I check, with `'+>'` and `'+<'`. OTOH it is not entirely clear if the above text is to mean that "in memory" files should be provided only in write mode or whenever the third argument is a scalar reference...	[reply] [d/l] [select]

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Re^2: Clash between IO layers and "in memory" files?
by blazar (Canon) on Mar 29, 2007 at 12:38 UTC

Similar behavior when you try to auto-open a string ref via @ARGV

Well, I had never thought of that and never seen it documented, although it would certainly be useful a feature to have. But it is somewhat annoying that e.g. '<' works and '<:raw' doesn't. perldoc -f open, now that I notice, only says:

Since v5.8.0, perl has built using PerlIO by default. Unless
you've changed this (i.e. Configure -Uuseperlio), you can open
file handles to "in memory" files held in Perl scalars via:

    open($fh, '>', \$variable) || ..
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There's another example later (and no other ones) again with '>', but the technique also works in read mode and, now that I check, with '+>' and '+<'. OTOH it is not entirely clear if the above text is to mean that "in memory" files should be provided only in write mode or whenever the third argument is a scalar reference...

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