diff options
| author | Simon Cozens <simon@netthink.co.uk> | 2001-05-12 18:58:41 +0100 |
|---|---|---|
| committer | Jarkko Hietaniemi <jhi@iki.fi> | 2001-05-25 12:24:45 +0000 |
| commit | ac7cd81aae231be8bd5734f1506e627995fef570 (patch) | |
| tree | 1afabad86fa3c13ab376d2b27373051baf9ff235 | |
| parent | e66fb0c202c476a67c63915139a2545b39101339 (diff) | |
| download | perl-ac7cd81aae231be8bd5734f1506e627995fef570.tar.gz | |
Based on
Subject: [PATCH pp.c] Wrapping pack("C",256)
Message-ID: <20010512175841.A6132@netthink.co.uk>
p4raw-id: //depot/perl@10209
| -rw-r--r-- | pod/perldiag.pod | 30 | ||||
| -rw-r--r-- | pp.c | 23 | ||||
| -rw-r--r-- | t/pragma/warn/pp | 40 |
3 files changed, 90 insertions, 3 deletions
diff --git a/pod/perldiag.pod b/pod/perldiag.pod index 19ac8f31b4..afcc2ccade 100644 --- a/pod/perldiag.pod +++ b/pod/perldiag.pod @@ -1076,6 +1076,36 @@ references can be weakened. with an assignment operator, which implies modifying the value itself. Perhaps you need to copy the value to a temporary, and repeat that. +=item Character in "C" format wrapped + +(W pack) You said + + pack("C", $x) + +where $x is either less than 0 or more than 255; the C<"C"> format is +only for encoding native operating system characters (ASCII, EBCDIC, +and so on) and not for Unicode characters, so Perl behaved as if you meant + + pack("C", $x & 255) + +If you actually want to pack Unicode codepoints, use the C<"U"> format +instead. + +=item Character in "c" format wrapped + +(W pack) You said + + pack("c", $x) + +where $x is either less than -128 or more than 127; the C<"c"> format +is only for encoding native operating system characters (ASCII, EBCDIC, +and so on) and not for Unicode characters, so Perl behaved as if you meant + + pack("c", $x & 255); + +If you actually want to pack Unicode codepoints, use the C<"U"> format +instead. + =item chmod() mode argument is missing initial 0 (W chmod) A novice will sometimes say @@ -5465,9 +5465,26 @@ PP(pp_pack) case 'c': while (len-- > 0) { fromstr = NEXTFROM; - aint = SvIV(fromstr); - achar = aint; - sv_catpvn(cat, &achar, sizeof(char)); + switch (datumtype) { + case 'C': + aint = SvIV(fromstr); + if ((aint < 0 || aint > 255) && + ckWARN(WARN_PACK)) + Perl_warner(aTHX_ WARN_PACK, + "Character in \"C\" format wrapped"); + achar = aint & 255; + sv_catpvn(cat, &achar, sizeof(char)); + break; + case 'c': + aint = SvIV(fromstr); + if ((aint < -128 || aint > 127) && + ckWARN(WARN_PACK)) + Perl_warner(aTHX_ WARN_PACK, + "Character in \"c\" format wrapped"); + achar = aint & 255; + sv_catpvn(cat, &achar, sizeof(char)); + break; + } } break; case 'U': diff --git a/t/pragma/warn/pp b/t/pragma/warn/pp index 8f42ba64ec..62f054a6ee 100644 --- a/t/pragma/warn/pp +++ b/t/pragma/warn/pp @@ -108,3 +108,43 @@ $_ = "\x80 \xff" ; reverse ; EXPECT ######## +# pp.c +use warnings 'pack' ; +print unpack("C", pack("C", -1)), "\n"; +print unpack("C", pack("C", 0)), "\n"; +print unpack("C", pack("C", 255)), "\n"; +print unpack("C", pack("C", 256)), "\n"; +print unpack("c", pack("c", -129)), "\n"; +print unpack("c", pack("c", -128)), "\n"; +print unpack("c", pack("c", 127)), "\n"; +print unpack("c", pack("c", 128)), "\n"; +no warnings 'pack' ; +print unpack("C", pack("C", -1)), "\n"; +print unpack("C", pack("C", 0)), "\n"; +print unpack("C", pack("C", 255)), "\n"; +print unpack("C", pack("C", 256)), "\n"; +print unpack("c", pack("c", -129)), "\n"; +print unpack("c", pack("c", -128)), "\n"; +print unpack("c", pack("c", 127)), "\n"; +print unpack("c", pack("c", 128)), "\n"; +EXPECT +Character in "C" format wrapped at - line 3. +Character in "C" format wrapped at - line 6. +Character in "c" format wrapped at - line 7. +Character in "c" format wrapped at - line 10. +255 +0 +255 +0 +127 +-128 +127 +-128 +255 +0 +255 +0 +127 +-128 +127 +-128 |