Re: Using the DATA file handle for ARGV

This snippet is really interesting and could prove useful later, thanks for sharing (:

There's something I find strange. Typeglob aliasing usually transfers all magic. Try this:

*a = *\; $a = 42; print; # prints 42

However, in this case, it looks like @ARGV and $ARGV are stripped of all magic by the manipulation (@DATA and $DATA ain't getting any magic neither). Can somebody explain what's happening there?

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Re^2: Using the DATA file handle for ARGV by ikegami (Patriarch) on Nov 13, 2013 at 18:22 UTC
it looks like @ARGV and $ARGV are stripped of all magic by the manipulation No, they were never magical in the first place. `>perl -MDevel::Peek -e"Dump($ARGV,1);" 2>&1 \| find "MAGIC" >perl -MDevel::Peek -e"Dump(\@ARGV,1);" 2>&1 \| find "MAGIC" >perl -MDevel::Peek -e"Dump(\%ENV,1);" 2>&1 \| find "MAGIC" MAGIC = 0x4c7ed8 MG_TYPE = PERL_MAGIC_env(E)` [download] They are simply set by reading from the magical file handle ARGV, which is no longer being read from.	[reply] [d/l]
Re^2: Using the DATA file handle for ARGV by Anonymous Monk on Jun 01, 2013 at 06:54 UTC
However, in this case, it looks like @ARGV and $ARGV are stripped of all magic by the manipulation (@DATA and $DATA ain't getting any magic neither). Can somebody explain what's happening there? Why would there be "magic", and what would this "magic" do?	[reply]
Re^3: Using the DATA file handle for ARGV by Grimy (Pilgrim) on Jun 01, 2013 at 21:30 UTC
`@ARGV = 'echo 42 \|'; print <>; # prints 42 print $ARGV; # prints echo 42\|` [download] Unless I'm mistaken, this illustrates that both `@ARGV` and `$ARGV` are usually magic. But I thing I got it. There's isn't actually any magic in `@ARGV` and `$ARGV`. It's just the magic `ARGV{IO}` that pops `@ARGV` and writes `$ARGV`. Once the magic `ARGV{IO}` is gone, those variables are nothing special. Or am I still completely mistaken?	[reply] [d/l] [select]
Re^4: Using the DATA file handle for ARGV by Anonymous Monk on Jun 02, 2013 at 00:43 UTC
Once the magic ARGV{IO} is gone, those variables are nothing special. Or am I still completely mistaken?* I think you're right. I think the magic belongs to readline ARGV , not readline DATA, and when you do ARGV = DATA it makes ARGV an alias for DATA, doesn't make DATA an alias for ARGV, so DATA has no magic `$ echo \|perl -e " ARGV = DATA; print while <DATA> " $ echo \|perl -e " DATA = ARGV; print while <DATA> " ECHO is on.` [download]	[reply] [d/l]