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| author | Gurusamy Sarathy <gsar@cpan.org> | 1999-05-08 16:56:02 +0000 |
|---|---|---|
| committer | Gurusamy Sarathy <gsar@cpan.org> | 1999-05-08 16:56:02 +0000 |
| commit | 3160c39162b19f4390e9806b11fb472bc602a6bd (patch) | |
| tree | ee6626a62cc7f199d9a87d24d87c7564033ceb8a | |
| parent | e16b8f4913aae827d19b2f53293805a3a74f33c6 (diff) | |
| download | perl-3160c39162b19f4390e9806b11fb472bc602a6bd.tar.gz | |
mention unpack('pP',...) footshot (from Albert Dvornik <bert@genscan.com>)
p4raw-id: //depot/perl@3333
| -rw-r--r-- | pod/perlfunc.pod | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod index b2231a3a87..a65e3e3e46 100644 --- a/pod/perlfunc.pod +++ b/pod/perlfunc.pod @@ -4613,6 +4613,11 @@ The following efficiently counts the number of set bits in a bit vector: $setbits = unpack("%32b*", $selectmask); +The C<"p"> and C<"P"> formats should be used with care. Since Perl +has no way of checking whether the value passed to C<unpack()> +corresponds to a valid memory location, passing a pointer value that's +not known to be valid is likely to have disastrous consequences. + See L</pack> for more examples. =item untie VARIABLE |