NG4R3P

Linux 4gvps.4gvps.com 3.10.0-1127.18.2.vz7.163.46 #1 SMP Fri Nov 20 21:47:55 MSK 2020 x86_64
SOFT : Apache PHP : 7.4.33
/usr/share/perl5/pod/

38.135.39.45

[ NAME ]	[ SIZE ]	[ PERM ]	[ DATE ]	[ ACT ]
+FILE +DIR
a2p.pod	5.962 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl.pod	15.429 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5004delta.pod	54.921 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5005delta.pod	33.48 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5100delta.pod	53.413 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5101delta.pod	42.858 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5120delta.pod	87.193 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5121delta.pod	9.905 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5122delta.pod	9.378 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5123delta.pod	4.004 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5124delta.pod	3.586 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5140delta.pod	140.941 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5141delta.pod	7.779 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5142delta.pod	6.73 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5143delta.pod	7.578 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5160delta.pod	130.52 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5161delta.pod	5.998 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5162delta.pod	3.51 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5163delta.pod	3.985 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl561delta.pod	121.786 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl56delta.pod	104.685 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl581delta.pod	37.168 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl582delta.pod	4.365 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl583delta.pod	6.187 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl584delta.pod	7.19 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl585delta.pod	5.751 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl586delta.pod	4.542 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl587delta.pod	8.161 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl588delta.pod	24.68 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl589delta.pod	52.637 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl58delta.pod	112.215 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlaix.pod	18.768 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlamiga.pod	6.869 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlapi.pod	315.465 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlapio.pod	18.878 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlartistic.pod	6.846 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbeos.pod	2.867 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbook.pod	7.192 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlboot.pod	0.179 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbot.pod	0.178 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbs2000.pod	7.733 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcall.pod	54.026 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlce.pod	8.723 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcheat.pod	4.395 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlclib.pod	7.504 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcn.pod	4.815 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcommunity.pod	6.293 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcygwin.pod	27.17 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldata.pod	36.331 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldbmfilter.pod	4.863 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldebguts.pod	36.789 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldebtut.pod	20.786 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldebug.pod	38.151 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldelta.pod	3.985 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldgux.pod	2.754 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldiag.pod	207.818 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldos.pod	10.275 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldsc.pod	24.837 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldtrace.pod	6.209 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlebcdic.pod	67.605 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlembed.pod	35.209 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlepoc.pod	3.572 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlexperiment.pod	4.843 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq.pod	22.007 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq1.pod	13.519 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq2.pod	9.278 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq3.pod	37.464 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq4.pod	87.393 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq5.pod	54.113 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq6.pod	38.664 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq7.pod	36.352 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq8.pod	48.279 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq9.pod	14.709 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfork.pod	12.782 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlform.pod	16.287 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfreebsd.pod	1.554 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfunc.pod	338.432 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlgit.pod	29.755 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlglossary.pod	110.655 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlgpl.pod	13.537 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlguts.pod	111.664 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhack.pod	35.03 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhacktips.pod	45.498 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhacktut.pod	6.068 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhaiku.pod	1.469 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhist.pod	43.319 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhpux.pod	28.065 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhurd.pod	1.94 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlintern.pod	42.532 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlinterp.pod	30.002 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlintro.pod	22.085 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perliol.pod	33.027 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlipc.pod	70.165 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlirix.pod	4.291 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perljp.pod	7.572 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlko.pod	7.521 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllexwarn.pod	14.612 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllinux.pod	1.453 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllocale.pod	51.435 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllol.pod	10.935 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmacos.pod	0.978 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmacosx.pod	10.399 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmod.pod	24.041 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmodinstall.pod	12.412 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmodlib.pod	78.491 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmodstyle.pod	20.757 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmpeix.pod	14.236 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmroapi.pod	3.128 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlnetware.pod	6.348 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlnewmod.pod	10.952 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlnumber.pod	8.156 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlobj.pod	33.653 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlootut.pod	25.604 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlop.pod	121.731 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlopenbsd.pod	1.176 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlopentut.pod	37.533 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlos2.pod	90.533 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlos390.pod	15.2 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlos400.pod	4.513 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpacktut.pod	49.834 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlperf.pod	50.048 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlplan9.pod	5.005 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpod.pod	21.27 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpodspec.pod	66.203 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpolicy.pod	19.726 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlport.pod	82.635 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpragma.pod	5.105 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlqnx.pod	4.145 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlre.pod	100.761 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreapi.pod	25.168 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrebackslash.pod	25.644 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrecharclass.pod	34.188 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlref.pod	28.319 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreftut.pod	18.232 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreguts.pod	35.995 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrequick.pod	17.499 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreref.pod	14.19 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlretut.pod	115.128 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlriscos.pod	1.493 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrun.pod	49.575 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsec.pod	22.768 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsolaris.pod	28.63 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsource.pod	6.194 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlstyle.pod	8.416 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsub.pod	55.153 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsymbian.pod	15.439 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsyn.pod	41.044 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlthrtut.pod	45.407 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltie.pod	37.02 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltoc.pod	638.995 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltodo.pod	0.354 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltooc.pod	0.179 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltoot.pod	0.179 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltrap.pod	40.281 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltru64.pod	7.552 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltw.pod	5.151 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlunicode.pod	70.891 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlunifaq.pod	13.314 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perluniintro.pod	35.443 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perluniprops.pod	229.736 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlunitut.pod	7.756 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlutil.pod	9.679 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perluts.pod	3.105 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvar.pod	69.188 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvmesa.pod	3.881 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvms.pod	51.333 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvos.pod	5.823 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlwin32.pod	34.581 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlxs.pod	71.663 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlxstut.pod	48.517 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlxstypemap.pod	22.966 KB	-rw-r--r--	2023-10-25 12:41	R E G D
REQUEST EXIT

=head1 NAME perl5004delta - what's new for perl5.004 =head1 DESCRIPTION This document describes differences between the 5.003 release (as documented in I, second edition--the Camel Book) and this one. =head1 Supported Environments Perl5.004 builds out of the box on Unix, Plan 9, LynxOS, VMS, OS/2, QNX, AmigaOS, and Windows NT. Perl runs on Windows 95 as well, but it cannot be built there, for lack of a reasonable command interpreter. =head1 Core Changes Most importantly, many bugs were fixed, including several security problems. See the F file in the distribution for details. =head2 List assignment to %ENV works C<%ENV = ()> and C<%ENV = @list> now work as expected (except on VMS where it generates a fatal error). =head2 Change to "Can't locate Foo.pm in @INC" error The error "Can't locate Foo.pm in @INC" now lists the contents of @INC for easier debugging. =head2 Compilation option: Binary compatibility with 5.003 There is a new Configure question that asks if you want to maintain binary compatibility with Perl 5.003. If you choose binary compatibility, you do not have to recompile your extensions, but you might have symbol conflicts if you embed Perl in another application, just as in the 5.003 release. By default, binary compatibility is preserved at the expense of symbol table pollution. =head2 $PERL5OPT environment variable You may now put Perl options in the $PERL5OPT environment variable. Unless Perl is running with taint checks, it will interpret this variable as if its contents had appeared on a "#!perl" line at the beginning of your script, except that hyphens are optional. PERL5OPT may only be used to set the following switches: B<-[DIMUdmw]>. =head2 Limitations on B<-M>, B<-m>, and B<-T> options The C<-M> and C<-m> options are no longer allowed on the C<#!> line of a script. If a script needs a module, it should invoke it with the C pragma. The B<-T> option is also forbidden on the C<#!> line of a script, unless it was present on the Perl command line. Due to the way C<#!> works, this usually means that B<-T> must be in the first argument. Thus: #!/usr/bin/perl -T -w will probably work for an executable script invoked as C, while: #!/usr/bin/perl -w -T will probably fail under the same conditions. (Non-Unix systems will probably not follow this rule.) But C is guaranteed to fail, since then there is no chance of B<-T> being found on the command line before it is found on the C<#!> line. =head2 More precise warnings If you removed the B<-w> option from your Perl 5.003 scripts because it made Perl too verbose, we recommend that you try putting it back when you upgrade to Perl 5.004. Each new perl version tends to remove some undesirable warnings, while adding new warnings that may catch bugs in your scripts. =head2 Deprecated: Inherited C for non-methods Before Perl 5.004, C functions were looked up as methods (using the C<@ISA> hierarchy), even when the function to be autoloaded was called as a plain function (e.g. C), not a method (e.g. C<< Foo->bar() >> or C<< $obj->bar() >>). Perl 5.005 will use method lookup only for methods' Cs. However, there is a significant base of existing code that may be using the old behavior. So, as an interim step, Perl 5.004 issues an optional warning when a non-method uses an inherited C. The simple rule is: Inheritance will not work when autoloading non-methods. The simple fix for old code is: In any module that used to depend on inheriting C for non-methods from a base class named C, execute C<*AUTOLOAD = \&BaseClass::AUTOLOAD> during startup. =head2 Previously deprecated %OVERLOAD is no longer usable Using %OVERLOAD to define overloading was deprecated in 5.003. Overloading is now defined using the overload pragma. %OVERLOAD is still used internally but should not be used by Perl scripts. See L for more details. =head2 Subroutine arguments created only when they're modified In Perl 5.004, nonexistent array and hash elements used as subroutine parameters are brought into existence only if they are actually assigned to (via C<@_>). Earlier versions of Perl vary in their handling of such arguments. Perl versions 5.002 and 5.003 always brought them into existence. Perl versions 5.000 and 5.001 brought them into existence only if they were not the first argument (which was almost certainly a bug). Earlier versions of Perl never brought them into existence. For example, given this code: undef @a; undef %a; sub show { print $_[0] }; sub change { $_[0]++ }; show($a[2]); change($a{b}); After this code executes in Perl 5.004, $a{b} exists but $a[2] does not. In Perl 5.002 and 5.003, both $a{b} and $a[2] would have existed (but $a[2]'s value would have been undefined). =head2 Group vector changeable with C<$)> The C<$)> special variable has always (well, in Perl 5, at least) reflected not only the current effective group, but also the group list as returned by the C C function (if there is one). However, until this release, there has not been a way to call the C C function from Perl. In Perl 5.004, assigning to C<$)> is exactly symmetrical with examining it: The first number in its string value is used as the effective gid; if there are any numbers after the first one, they are passed to the C C function (if there is one). =head2 Fixed parsing of $$, &$, etc. Perl versions before 5.004 misinterpreted any type marker followed by "$" and a digit. For example, "$$0" was incorrectly taken to mean "${$}0" instead of "${$0}". This bug is (mostly) fixed in Perl 5.004. However, the developers of Perl 5.004 could not fix this bug completely, because at least two widely-used modules depend on the old meaning of "$$0" in a string. So Perl 5.004 still interprets "$$" in the old (broken) way inside strings; but it generates this message as a warning. And in Perl 5.005, this special treatment will cease. =head2 Fixed localization of $, $&, etc. Perl versions before 5.004 did not always properly localize the regex-related special variables. Perl 5.004 does localize them, as the documentation has always said it should. This may result in $1, $2, etc. no longer being set where existing programs use them. =head2 No resetting of $. on implicit close The documentation for Perl 5.0 has always stated that C<$.> is I reset when an already-open file handle is reopened with no intervening call to C. Due to a bug, perl versions 5.000 through 5.003 I reset C<$.> under that circumstance; Perl 5.004 does not. =head2 C may return undef The C operator returns true if a subroutine is expected to return a list, and false otherwise. In Perl 5.004, C can also return the undefined value if a subroutine's return value will not be used at all, which allows subroutines to avoid a time-consuming calculation of a return value if it isn't going to be used. =head2 C determines value of EXPR in scalar context Perl (version 5) used to determine the value of EXPR inconsistently, sometimes incorrectly using the surrounding context for the determination. Now, the value of EXPR (before being parsed by eval) is always determined in a scalar context. Once parsed, it is executed as before, by providing the context that the scope surrounding the eval provided. This change makes the behavior Perl4 compatible, besides fixing bugs resulting from the inconsistent behavior. This program: @a = qw(time now is time); print eval @a; print '|', scalar eval @a; used to print something like "timenowis881399109|4", but now (and in perl4) prints "4|4". =head2 Changes to tainting checks A bug in previous versions may have failed to detect some insecure conditions when taint checks are turned on. (Taint checks are used in setuid or setgid scripts, or when explicitly turned on with the C<-T> invocation option.) Although it's unlikely, this may cause a previously-working script to now fail, which should be construed as a blessing since that indicates a potentially-serious security hole was just plugged. The new restrictions when tainting include: =over 4 =item No glob() or <*> These operators may spawn the C shell (csh), which cannot be made safe. This restriction will be lifted in a future version of Perl when globbing is implemented without the use of an external program. =item No spawning if tainted $CDPATH, $ENV, $BASH_ENV These environment variables may alter the behavior of spawned programs (especially shells) in ways that subvert security. So now they are treated as dangerous, in the manner of $IFS and $PATH. =item No spawning if tainted $TERM doesn't look like a terminal name Some termcap libraries do unsafe things with $TERM. However, it would be unnecessarily harsh to treat all $TERM values as unsafe, since only shell metacharacters can cause trouble in $TERM. So a tainted $TERM is considered to be safe if it contains only alphanumerics, underscores, dashes, and colons, and unsafe if it contains other characters (including whitespace). =back =head2 New Opcode module and revised Safe module A new Opcode module supports the creation, manipulation and application of opcode masks. The revised Safe module has a new API and is implemented using the new Opcode module. Please read the new Opcode and Safe documentation. =head2 Embedding improvements In older versions of Perl it was not possible to create more than one Perl interpreter instance inside a single process without leaking like a sieve and/or crashing. The bugs that caused this behavior have all been fixed. However, you still must take care when embedding Perl in a C program. See the updated perlembed manpage for tips on how to manage your interpreters. =head2 Internal change: FileHandle class based on IO::* classes File handles are now stored internally as type IO::Handle. The FileHandle module is still supported for backwards compatibility, but it is now merely a front end to the IO::* modules, specifically IO::Handle, IO::Seekable, and IO::File. We suggest, but do not require, that you use the IO::* modules in new code. In harmony with this change, C<*GLOB{FILEHANDLE}> is now just a backward-compatible synonym for C<*GLOB{IO}>. =head2 Internal change: PerlIO abstraction interface It is now possible to build Perl with AT&T's sfio IO package instead of stdio. See L for more details, and the F file for how to use it. =head2 New and changed syntax =over 4 =item $coderef->(PARAMS) A subroutine reference may now be suffixed with an arrow and a (possibly empty) parameter list. This syntax denotes a call of the referenced subroutine, with the given parameters (if any). This new syntax follows the pattern of S{FOO} >>> and S[$foo] >>>: You may now write S> as S($foo) >>>. All these arrow terms may be chained; thus, S{FOO}}($bar) >>> may now be written S{FOO}->($bar) >>>. =back =head2 New and changed builtin constants =over 4 =item __PACKAGE__ The current package name at compile time, or the undefined value if there is no current package (due to a C directive). Like C<__FILE__> and C<__LINE__>, C<__PACKAGE__> does I interpolate into strings. =back =head2 New and changed builtin variables =over 4 =item $^E Extended error message on some platforms. (Also known as $EXTENDED_OS_ERROR if you C). =item $^H The current set of syntax checks enabled by C. See the documentation of C for more details. Not actually new, but newly documented. Because it is intended for internal use by Perl core components, there is no C long name for this variable. =item $^M By default, running out of memory it is not trappable. However, if compiled for this, Perl may use the contents of C<$^M> as an emergency pool after die()ing with this message. Suppose that your Perl were compiled with -DPERL_EMERGENCY_SBRK and used Perl's malloc. Then $^M = 'a' x (1<<16); would allocate a 64K buffer for use when in emergency. See the F file for information on how to enable this option. As a disincentive to casual use of this advanced feature, there is no C long name for this variable. =back =head2 New and changed builtin functions =over 4 =item delete on slices This now works. (e.g. C) =item flock is now supported on more platforms, prefers fcntl to lockf when emulating, and always flushes before (un)locking. =item printf and sprintf Perl now implements these functions itself; it doesn't use the C library function sprintf() any more, except for floating-point numbers, and even then only known flags are allowed. As a result, it is now possible to know which conversions and flags will work, and what they will do. The new conversions in Perl's sprintf() are: %i a synonym for %d %p a pointer (the address of the Perl value, in hexadecimal) %n special: *stores* the number of characters output so far into the next variable in the parameter list The new flags that go between the C<%> and the conversion are: # prefix octal with "0", hex with "0x" h interpret integer as C type "short" or "unsigned short" V interpret integer as Perl's standard integer type Also, where a number would appear in the flags, an asterisk ("*") may be used instead, in which case Perl uses the next item in the parameter list as the given number (that is, as the field width or precision). If a field width obtained through "*" is negative, it has the same effect as the '-' flag: left-justification. See L for a complete list of conversion and flags. =item keys as an lvalue As an lvalue, C allows you to increase the number of hash buckets allocated for the given hash. This can gain you a measure of efficiency if you know the hash is going to get big. (This is similar to pre-extending an array by assigning a larger number to $#array.) If you say keys %hash = 200; then C<%hash> will have at least 200 buckets allocated for it. These buckets will be retained even if you do C<%hash = ()>; use C if you want to free the storage while C<%hash> is still in scope. You can't shrink the number of buckets allocated for the hash using C in this way (but you needn't worry about doing this by accident, as trying has no effect). =item my() in Control Structures You can now use my() (with or without the parentheses) in the control expressions of control structures such as: while (defined(my $line = <>)) { $line = lc $line; } continue { print $line; } if ((my $answer = ) =~ /^y(es)?$/i) { user_agrees(); } elsif ($answer =~ /^n(o)?$/i) { user_disagrees(); } else { chomp $answer; die "`$answer' is neither `yes' nor `no'"; } Also, you can declare a foreach loop control variable as lexical by preceding it with the word "my". For example, in: foreach my $i (1, 2, 3) { some_function(); } $i is a lexical variable, and the scope of $i extends to the end of the loop, but not beyond it. Note that you still cannot use my() on global punctuation variables such as $_ and the like. =item pack() and unpack() A new format 'w' represents a BER compressed integer (as defined in ASN.1). Its format is a sequence of one or more bytes, each of which provides seven bits of the total value, with the most significant first. Bit eight of each byte is set, except for the last byte, in which bit eight is clear. If 'p' or 'P' are given undef as values, they now generate a NULL pointer. Both pack() and unpack() now fail when their templates contain invalid types. (Invalid types used to be ignored.) =item sysseek() The new sysseek() operator is a variant of seek() that sets and gets the file's system read/write position, using the lseek(2) system call. It is the only reliable way to seek before using sysread() or syswrite(). Its return value is the new position, or the undefined value on failure. =item use VERSION If the first argument to C is a number, it is treated as a version number instead of a module name. If the version of the Perl interpreter is less than VERSION, then an error message is printed and Perl exits immediately. Because C occurs at compile time, this check happens immediately during the compilation process, unlike C, which waits until runtime for the check. This is often useful if you need to check the current Perl version before Cing library modules which have changed in incompatible ways from older versions of Perl. (We try not to do this more than we have to.) =item use Module VERSION LIST If the VERSION argument is present between Module and LIST, then the C will call the VERSION method in class Module with the given version as an argument. The default VERSION method, inherited from the UNIVERSAL class, croaks if the given version is larger than the value of the variable $Module::VERSION. (Note that there is not a comma after VERSION!) This version-checking mechanism is similar to the one currently used in the Exporter module, but it is faster and can be used with modules that don't use the Exporter. It is the recommended method for new code. =item prototype(FUNCTION) Returns the prototype of a function as a string (or C if the function has no prototype). FUNCTION is a reference to or the name of the function whose prototype you want to retrieve. (Not actually new; just never documented before.) =item srand The default seed for C, which used to be C, has been changed. Now it's a heady mix of difficult-to-predict system-dependent values, which should be sufficient for most everyday purposes. Previous to version 5.004, calling C without first calling C would yield the same sequence of random numbers on most or all machines. Now, when perl sees that you're calling C and haven't yet called C, it calls C with the default seed. You should still call C manually if your code might ever be run on a pre-5.004 system, of course, or if you want a seed other than the default. =item $_ as Default Functions documented in the Camel to default to $_ now in fact do, and all those that do are so documented in L. =item C does not reset search position on failure The C match iteration construct has always reset its target string's search position (which is visible through the C operator) when a match fails; as a result, the next C match after a failure starts again at the beginning of the string. With Perl 5.004, this reset may be disabled by adding the "c" (for "continue") modifier, i.e. C. This feature, in conjunction with the C<\G> zero-width assertion, makes it possible to chain matches together. See L and L. =item C ignores whitespace before ?*+{} The C construct has always been intended to ignore all unescaped whitespace. However, before Perl 5.004, whitespace had the effect of escaping repeat modifiers like "*" or "?"; for example, C was (mis)interpreted as C. This bug has been fixed in 5.004. =item nested C closures work now Prior to the 5.004 release, nested anonymous functions didn't work right. They do now. =item formats work right on changing lexicals Just like anonymous functions that contain lexical variables that change (like a lexical index variable for a C loop), formats now work properly. For example, this silently failed before (printed only zeros), but is fine now: my $i; foreach $i ( 1 .. 10 ) { write; } format = my i is @# $i . However, it still fails (without a warning) if the foreach is within a subroutine: my $i; sub foo { foreach $i ( 1 .. 10 ) { write; } } foo; format = my i is @# $i . =back =head2 New builtin methods The C package automatically contains the following methods that are inherited by all other classes: =over 4 =item isa(CLASS) C returns I if its object is blessed into a subclass of C C is also exportable and can be called as a sub with two arguments. This allows the ability to check what a reference points to. Example: use UNIVERSAL qw(isa); if(isa($ref, 'ARRAY')) { ... } =item can(METHOD) C checks to see if its object has a method called C, if it does then a reference to the sub is returned; if it does not then I is returned. =item VERSION( [NEED] ) C returns the version number of the class (package). If the NEED argument is given then it will check that the current version (as defined by the $VERSION variable in the given package) not less than NEED; it will die if this is not the case. This method is normally called as a class method. This method is called automatically by the C form of C. use A 1.2 qw(some imported subs); # implies: A->VERSION(1.2); =back B C directly uses Perl's internal code for method lookup, and C uses a very similar method and caching strategy. This may cause strange effects if the Perl code dynamically changes @ISA in any package. You may add other methods to the UNIVERSAL class via Perl or XS code. You do not need to C in order to make these methods available to your program. This is necessary only if you wish to have C available as a plain subroutine in the current package. =head2 TIEHANDLE now supported See L for other kinds of tie()s. =over 4 =item TIEHANDLE classname, LIST This is the constructor for the class. That means it is expected to return an object of some sort. The reference can be used to hold some internal information. sub TIEHANDLE { print "\n"; my $i; return bless \$i, shift; } =item PRINT this, LIST This method will be triggered every time the tied handle is printed to. Beyond its self reference it also expects the list that was passed to the print function. sub PRINT { $r = shift; $$r++; return print join( $, => map {uc} @_), $\; } =item PRINTF this, LIST This method will be triggered every time the tied handle is printed to with the C function. Beyond its self reference it also expects the format and list that was passed to the printf function. sub PRINTF { shift; my $fmt = shift; print sprintf($fmt, @_)."\n"; } =item READ this LIST This method will be called when the handle is read from via the C or C functions. sub READ { $r = shift; my($buf,$len,$offset) = @_; print "READ called, \$buf=$buf, \$len=$len, \$offset=$offset"; } =item READLINE this This method will be called when the handle is read from. The method should return undef when there is no more data. sub READLINE { $r = shift; return "PRINT called $$r times\n" } =item GETC this This method will be called when the C function is called. sub GETC { print "Don't GETC, Get Perl"; return "a"; } =item DESTROY this As with the other types of ties, this method will be called when the tied handle is about to be destroyed. This is useful for debugging and possibly for cleaning up. sub DESTROY { print "\n"; } =back =head2 Malloc enhancements If perl is compiled with the malloc included with the perl distribution (that is, if C is 'define') then you can print memory statistics at runtime by running Perl thusly: env PERL_DEBUG_MSTATS=2 perl your_script_here The value of 2 means to print statistics after compilation and on exit; with a value of 1, the statistics are printed only on exit. (If you want the statistics at an arbitrary time, you'll need to install the optional module Devel::Peek.) Three new compilation flags are recognized by malloc.c. (They have no effect if perl is compiled with system malloc().) =over 4 =item -DPERL_EMERGENCY_SBRK If this macro is defined, running out of memory need not be a fatal error: a memory pool can allocated by assigning to the special variable C<$^M>. See L<"$^M">. =item -DPACK_MALLOC Perl memory allocation is by bucket with sizes close to powers of two. Because of these malloc overhead may be big, especially for data of size exactly a power of two. If C is defined, perl uses a slightly different algorithm for small allocations (up to 64 bytes long), which makes it possible to have overhead down to 1 byte for allocations which are powers of two (and appear quite often). Expected memory savings (with 8-byte alignment in C) is about 20% for typical Perl usage. Expected slowdown due to additional malloc overhead is in fractions of a percent (hard to measure, because of the effect of saved memory on speed). =item -DTWO_POT_OPTIMIZE Similarly to C, this macro improves allocations of data with size close to a power of two; but this works for big allocations (starting with 16K by default). Such allocations are typical for big hashes and special-purpose scripts, especially image processing. On recent systems, the fact that perl requires 2M from system for 1M allocation will not affect speed of execution, since the tail of such a chunk is not going to be touched (and thus will not require real memory). However, it may result in a premature out-of-memory error. So if you will be manipulating very large blocks with sizes close to powers of two, it would be wise to define this macro. Expected saving of memory is 0-100% (100% in applications which require most memory in such 2**n chunks); expected slowdown is negligible. =back =head2 Miscellaneous efficiency enhancements Functions that have an empty prototype and that do nothing but return a fixed value are now inlined (e.g. C_{).

Each unique hash key is only allocated once, no matter how many hashes
have an entry with that key. So even if you have 100 copies of the
same hash, the hash keys never have to be reallocated.

=head1 Support for More Operating Systems

Support for the following operating systems is new in Perl 5.004.

=head2 Win32

Perl 5.004 now includes support for building a "native" perl under
Windows NT, using the Microsoft Visual C++ compiler (versions 2.0
and above) or the Borland C++ compiler (versions 5.02 and above).
The resulting perl can be used under Windows 95 (if it
is installed in the same directory locations as it got installed
in Windows NT). This port includes support for perl extension
building tools like L and L, so that many extensions
available on the Comprehensive Perl Archive Network (CPAN) can now be
readily built under Windows NT. See http://www.perl.com/ for more
information on CPAN and F in the perl distribution for more
details on how to get started with building this port.

There is also support for building perl under the Cygwin32 environment.
Cygwin32 is a set of GNU tools that make it possible to compile and run
many Unix programs under Windows NT by providing a mostly Unix-like
interface for compilation and execution. See F in the
perl distribution for more details on this port and how to obtain the
Cygwin32 toolkit.

=head2 Plan 9

See F in the perl distribution.

=head2 QNX

See F in the perl distribution.

=head2 AmigaOS

See F in the perl distribution.

=head1 Pragmata

Six new pragmatic modules exist:

=over 4

=item use autouse MODULE => qw(sub1 sub2 sub3)

Defers C until someone calls one of the specified
subroutines (which must be exported by MODULE). This pragma should be
used with caution, and only when necessary.

=item use blib

=item use blib 'dir'

Looks for MakeMaker-like I<'blib'> directory structure starting in
I (or current directory) and working back up to five levels of
parent directories.

Intended for use on command line with B<-M> option as a way of testing
arbitrary scripts against an uninstalled version of a package.

=item use constant NAME => VALUE

Provides a convenient interface for creating compile-time constants,
See L.

=item use locale

Tells the compiler to enable (or disable) the use of POSIX locales for
builtin operations.

When C is in effect, the current LC_CTYPE locale is used
for regular expressions and case mapping; LC_COLLATE for string
ordering; and LC_NUMERIC for numeric formatting in printf and sprintf
(but B in print). LC_NUMERIC is always used in write, since
lexical scoping of formats is problematic at best.

Each C or C affects statements to the end of
the enclosing BLOCK or, if not inside a BLOCK, to the end of the
current file. Locales can be switched and queried with
POSIX::setlocale().

See L for more information.

=item use ops

Disable unsafe opcodes, or any named opcodes, when compiling Perl code.

=item use vmsish

Enable VMS-specific language features. Currently, there are three
VMS-specific features available: 'status', which makes C<$?> and
C return genuine VMS status values instead of emulating POSIX;
'exit', which makes C take a genuine VMS status value instead of
assuming that C is an error; and 'time', which makes all times
relative to the local time zone, in the VMS tradition.

=back

=head1 Modules

=head2 Required Updates

Though Perl 5.004 is compatible with almost all modules that work
with Perl 5.003, there are a few exceptions:

Module Required Version for Perl 5.004
------ -------------------------------
Filter Filter-1.12
LWP libwww-perl-5.08
Tk Tk400.202 (-w makes noise)

Also, the majordomo mailing list program, version 1.94.1, doesn't work
with Perl 5.004 (nor with perl 4), because it executes an invalid
regular expression. This bug is fixed in majordomo version 1.94.2.

=head2 Installation directories

The I script now places the Perl source files for
extensions in the architecture-specific library directory, which is
where the shared libraries for extensions have always been. This
change is intended to allow administrators to keep the Perl 5.004
library directory unchanged from a previous version, without running
the risk of binary incompatibility between extensions' Perl source and
shared libraries.

=head2 Module information summary

Brand new modules, arranged by topic rather than strictly
alphabetically:

CGI.pm Web server interface ("Common Gateway Interface")
CGI/Apache.pm Support for Apache's Perl module
CGI/Carp.pm Log server errors with helpful context
CGI/Fast.pm Support for FastCGI (persistent server process)
CGI/Push.pm Support for server push
CGI/Switch.pm Simple interface for multiple server types

CPAN Interface to Comprehensive Perl Archive Network
CPAN::FirstTime Utility for creating CPAN configuration file
CPAN::Nox Runs CPAN while avoiding compiled extensions

IO.pm Top-level interface to IO::* classes
IO/File.pm IO::File extension Perl module
IO/Handle.pm IO::Handle extension Perl module
IO/Pipe.pm IO::Pipe extension Perl module
IO/Seekable.pm IO::Seekable extension Perl module
IO/Select.pm IO::Select extension Perl module
IO/Socket.pm IO::Socket extension Perl module

Opcode.pm Disable named opcodes when compiling Perl code

ExtUtils/Embed.pm Utilities for embedding Perl in C programs
ExtUtils/testlib.pm Fixes up @INC to use just-built extension

FindBin.pm Find path of currently executing program

Class/Struct.pm Declare struct-like datatypes as Perl classes
File/stat.pm By-name interface to Perl's builtin stat
Net/hostent.pm By-name interface to Perl's builtin gethost*
Net/netent.pm By-name interface to Perl's builtin getnet*
Net/protoent.pm By-name interface to Perl's builtin getproto*
Net/servent.pm By-name interface to Perl's builtin getserv*
Time/gmtime.pm By-name interface to Perl's builtin gmtime
Time/localtime.pm By-name interface to Perl's builtin localtime
Time/tm.pm Internal object for Time::{gm,local}time
User/grent.pm By-name interface to Perl's builtin getgr*
User/pwent.pm By-name interface to Perl's builtin getpw*

Tie/RefHash.pm Base class for tied hashes with references as keys

UNIVERSAL.pm Base class for *ALL* classes

=head2 Fcntl

New constants in the existing Fcntl modules are now supported,
provided that your operating system happens to support them:

F_GETOWN F_SETOWN
O_ASYNC O_DEFER O_DSYNC O_FSYNC O_SYNC
O_EXLOCK O_SHLOCK

These constants are intended for use with the Perl operators sysopen()
and fcntl() and the basic database modules like SDBM_File. For the
exact meaning of these and other Fcntl constants please refer to your
operating system's documentation for fcntl() and open().

In addition, the Fcntl module now provides these constants for use
with the Perl operator flock():

LOCK_SH LOCK_EX LOCK_NB LOCK_UN

These constants are defined in all environments (because where there is
no flock() system call, Perl emulates it). However, for historical
reasons, these constants are not exported unless they are explicitly
requested with the ":flock" tag (e.g. C).

=head2 IO

The IO module provides a simple mechanism to load all the IO modules at one
go. Currently this includes:

IO::Handle
IO::Seekable
IO::File
IO::Pipe
IO::Socket

For more information on any of these modules, please see its
respective documentation.

=head2 Math::Complex

The Math::Complex module has been totally rewritten, and now supports
more operations. These are overloaded:

+ - * / ** <=> neg ~ abs sqrt exp log sin cos atan2 "" (stringify)

And these functions are now exported:

pi i Re Im arg
log10 logn ln cbrt root
tan
csc sec cot
asin acos atan
acsc asec acot
sinh cosh tanh
csch sech coth
asinh acosh atanh
acsch asech acoth
cplx cplxe

=head2 Math::Trig

This new module provides a simpler interface to parts of Math::Complex for
those who need trigonometric functions only for real numbers.

=head2 DB_File

There have been quite a few changes made to DB_File. Here are a few of
the highlights:

=over 4

=item *

Fixed a handful of bugs.

=item *

By public demand, added support for the standard hash function exists().

=item *

Made it compatible with Berkeley DB 1.86.

=item *

Made negative subscripts work with RECNO interface.

=item *

Changed the default flags from O_RDWR to O_CREAT|O_RDWR and the default
mode from 0640 to 0666.

=item *

Made DB_File automatically import the open() constants (O_RDWR,
O_CREAT etc.) from Fcntl, if available.

=item *

Updated documentation.

=back

Refer to the HISTORY section in DB_File.pm for a complete list of
changes. Everything after DB_File 1.01 has been added since 5.003.

=head2 Net::Ping

Major rewrite - support added for both udp echo and real icmp pings.

=head2 Object-oriented overrides for builtin operators

Many of the Perl builtins returning lists now have
object-oriented overrides. These are:

File::stat
Net::hostent
Net::netent
Net::protoent
Net::servent
Time::gmtime
Time::localtime
User::grent
User::pwent

For example, you can now say

use File::stat;
use User::pwent;
$his = (stat($filename)->st_uid == pwent($whoever)->pw_uid);

=head1 Utility Changes

=head2 pod2html

=over 4

=item Sends converted HTML to standard output

The I utility included with Perl 5.004 is entirely new.
By default, it sends the converted HTML to its standard output,
instead of writing it to a file like Perl 5.003's I did.
Use the B<--outfile=FILENAME> option to write to a file.

=back

=head2 xsubpp

=over 4

=item C XSUBs now default to returning nothing

Due to a documentation/implementation bug in previous versions of
Perl, XSUBs with a return type of C have actually been
returning one value. Usually that value was the GV for the XSUB,
but sometimes it was some already freed or reused value, which would
sometimes lead to program failure.

In Perl 5.004, if an XSUB is declared as returning C, it
actually returns no value, i.e. an empty list (though there is a
backward-compatibility exception; see below). If your XSUB really
does return an SV, you should give it a return type of C.

For backward compatibility, I tries to guess whether a
C XSUB is really C or if it wants to return an C.
It does so by examining the text of the XSUB: if I finds
what looks like an assignment to C, it assumes that the
XSUB's return type is really C.

=back

=head1 C Language API Changes

=over 4

=item C and C

The C function finds a method for an object, just like
in Perl 5.003. The GV it returns may be a method cache entry.
However, in Perl 5.004, method cache entries are not visible to users;
therefore, they can no longer be passed directly to C.
Instead, you should use the C macro on the GV to extract its CV,
and pass the CV to C.

The most likely symptom of passing the result of C to
C is Perl's producing an "Undefined subroutine called"
error on the I call to a given method (since there is no cache
on the first call).

=item C

A new function handy for eval'ing strings of Perl code inside C code.
This function returns the value from the eval statement, which can
be used instead of fetching globals from the symbol table. See
L, L and L for details and examples.

=item Extended API for manipulating hashes

Internal handling of hash keys has changed. The old hashtable API is
still fully supported, and will likely remain so. The additions to the
API allow passing keys as Cs, so that C hashes can be given
real scalars as keys rather than plain strings (nontied hashes still
can only use strings as keys). New extensions must use the new hash
access functions and macros if they wish to use C keys. These
additions also make it feasible to manipulate Cs (hash entries),
which can be more efficient. See L for details.

=back

=head1 Documentation Changes

Many of the base and library pods were updated. These
new pods are included in section 1:

=over 4

=item L

This document.

=item L

Frequently asked questions.

=item L

Locale support (internationalization and localization).

=item L

Tutorial on Perl OO programming.

=item L

Perl internal IO abstraction interface.

=item L

Perl module library and recommended practice for module creation.
Extracted from L (which is much smaller as a result).

=item L

Although not new, this has been massively updated.

=item L

Although not new, this has been massively updated.

=back

=head1 New Diagnostics

Several new conditions will trigger warnings that were
silent before. Some only affect certain platforms.
The following new warnings and errors outline these.
These messages are classified as follows (listed in
increasing order of desperation):

(W) A warning (optional).
(D) A deprecation (optional).
(S) A severe warning (mandatory).
(F) A fatal error (trappable).
(P) An internal error you should never see (trappable).
(X) A very fatal error (nontrappable).
(A) An alien error message (not generated by Perl).

=over 4

=item "my" variable %s masks earlier declaration in same scope

(W) A lexical variable has been redeclared in the same scope, effectively
eliminating all access to the previous instance. This is almost always
a typographical error. Note that the earlier variable will still exist
until the end of the scope or until all closure referents to it are
destroyed.

=item %s argument is not a HASH element or slice

(F) The argument to delete() must be either a hash element, such as

$foo{$bar}
$ref->[12]->{"susie"}

or a hash slice, such as

@foo{$bar, $baz, $xyzzy}
@{$ref->[12]}{"susie", "queue"}

=item Allocation too large: %lx

(X) You can't allocate more than 64K on an MS-DOS machine.

=item Allocation too large

(F) You can't allocate more than 2^31+"small amount" bytes.

=item Applying %s to %s will act on scalar(%s)

(W) The pattern match (//), substitution (s///), and transliteration (tr///)
operators work on scalar values. If you apply one of them to an array
or a hash, it will convert the array or hash to a scalar value (the
length of an array or the population info of a hash) and then work on
that scalar value. This is probably not what you meant to do. See
L and L for alternatives.

=item Attempt to free nonexistent shared string

(P) Perl maintains a reference counted internal table of strings to
optimize the storage and access of hash keys and other strings. This
indicates someone tried to decrement the reference count of a string
that can no longer be found in the table.

=item Attempt to use reference as lvalue in substr

(W) You supplied a reference as the first argument to substr() used
as an lvalue, which is pretty strange. Perhaps you forgot to
dereference it first. See L.

=item Bareword "%s" refers to nonexistent package

(W) You used a qualified bareword of the form C, but
the compiler saw no other uses of that namespace before that point.
Perhaps you need to predeclare a package?

=item Can't redefine active sort subroutine %s

(F) Perl optimizes the internal handling of sort subroutines and keeps
pointers into them. You tried to redefine one such sort subroutine when it
was currently active, which is not allowed. If you really want to do
this, you should write C instead of C.

=item Can't use bareword ("%s") as %s ref while "strict refs" in use

(F) Only hard references are allowed by "strict refs". Symbolic references
are disallowed. See L.

=item Cannot resolve method `%s' overloading `%s' in package `%s'

(P) Internal error trying to resolve overloading specified by a method
name (as opposed to a subroutine reference).

=item Constant subroutine %s redefined

(S) You redefined a subroutine which had previously been eligible for
inlining. See L for commentary and
workarounds.

=item Constant subroutine %s undefined

(S) You undefined a subroutine which had previously been eligible for
inlining. See L for commentary and
workarounds.

=item Copy method did not return a reference

(F) The method which overloads "=" is buggy. See L.

=item Died

(F) You passed die() an empty string (the equivalent of C) or
you called it with no args and both C<$@> and C<$_> were empty.

=item Exiting pseudo-block via %s

(W) You are exiting a rather special block construct (like a sort block or
subroutine) by unconventional means, such as a goto, or a loop control
statement. See L.

=item Identifier too long

(F) Perl limits identifiers (names for variables, functions, etc.) to
252 characters for simple names, somewhat more for compound names (like
C<$A::B>). You've exceeded Perl's limits. Future versions of Perl are
likely to eliminate these arbitrary limitations.

=item Illegal character %s (carriage return)

(F) A carriage return character was found in the input. This is an
error, and not a warning, because carriage return characters can break
multi-line strings, including here documents (e.g., C).

=item Illegal switch in PERL5OPT: %s

(X) The PERL5OPT environment variable may only be used to set the
following switches: B<-[DIMUdmw]>.

=item Integer overflow in hex number

(S) The literal hex number you have specified is too big for your
architecture. On a 32-bit architecture the largest hex literal is
0xFFFFFFFF.

=item Integer overflow in octal number

(S) The literal octal number you have specified is too big for your
architecture. On a 32-bit architecture the largest octal literal is
037777777777.

=item internal error: glob failed

(P) Something went wrong with the external program(s) used for C
and C<< <*.c> >>. This may mean that your csh (C shell) is
broken. If so, you should change all of the csh-related variables in
config.sh: If you have tcsh, make the variables refer to it as if it
were csh (e.g. C); otherwise, make them all
empty (except that C should be C<'undef'>) so that Perl will
think csh is missing. In either case, after editing config.sh, run
C<./Configure -S> and rebuild Perl.

=item Invalid conversion in %s: "%s"

(W) Perl does not understand the given format conversion.
See L.

=item Invalid type in pack: '%s'

(F) The given character is not a valid pack type. See L.

=item Invalid type in unpack: '%s'

(F) The given character is not a valid unpack type. See L.

=item Name "%s::%s" used only once: possible typo

(W) Typographical errors often show up as unique variable names.
If you had a good reason for having a unique name, then just mention
it again somehow to suppress the message (the C pragma is
provided for just this purpose).

=item Null picture in formline

(F) The first argument to formline must be a valid format picture
specification. It was found to be empty, which probably means you
supplied it an uninitialized value. See L.

=item Offset outside string

(F) You tried to do a read/write/send/recv operation with an offset
pointing outside the buffer. This is difficult to imagine.
The sole exception to this is that Cing past the buffer
will extend the buffer and zero pad the new area.

=item Out of memory!

(X|F) The malloc() function returned 0, indicating there was insufficient
remaining memory (or virtual memory) to satisfy the request.

The request was judged to be small, so the possibility to trap it
depends on the way Perl was compiled. By default it is not trappable.
However, if compiled for this, Perl may use the contents of C<$^M> as
an emergency pool after die()ing with this message. In this case the
error is trappable I.

=item Out of memory during request for %s

(F) The malloc() function returned 0, indicating there was insufficient
remaining memory (or virtual memory) to satisfy the request. However,
the request was judged large enough (compile-time default is 64K), so
a possibility to shut down by trapping this error is granted.

=item panic: frexp

(P) The library function frexp() failed, making printf("%f") impossible.

=item Possible attempt to put comments in qw() list

(W) qw() lists contain items separated by whitespace; as with literal
strings, comment characters are not ignored, but are instead treated
as literal data. (You may have used different delimiters than the
parentheses shown here; braces are also frequently used.)

You probably wrote something like this:

@list = qw(
a # a comment
b # another comment
);

when you should have written this:

@list = qw(
a
b
);

If you really want comments, build your list the
old-fashioned way, with quotes and commas:

@list = (
'a', # a comment
'b', # another comment
);

=item Possible attempt to separate words with commas

(W) qw() lists contain items separated by whitespace; therefore commas
aren't needed to separate the items. (You may have used different
delimiters than the parentheses shown here; braces are also frequently
used.)

You probably wrote something like this:

qw! a, b, c !;

which puts literal commas into some of the list items. Write it without
commas if you don't want them to appear in your data:

qw! a b c !;

=item Scalar value @%s{%s} better written as $%s{%s}

(W) You've used a hash slice (indicated by @) to select a single element of
a hash. Generally it's better to ask for a scalar value (indicated by $).
The difference is that C<$foo{&bar}> always behaves like a scalar, both when
assigning to it and when evaluating its argument, while C<@foo{&bar}> behaves
like a list when you assign to it, and provides a list context to its
subscript, which can do weird things if you're expecting only one subscript.

=item Stub found while resolving method `%s' overloading `%s' in %s

(P) Overloading resolution over @ISA tree may be broken by importing stubs.
Stubs should never be implicitly created, but explicit calls to C
may break this.

=item Too late for "B<-T>" option

(X) The #! line (or local equivalent) in a Perl script contains the
B<-T> option, but Perl was not invoked with B<-T> in its argument
list. This is an error because, by the time Perl discovers a B<-T> in
a script, it's too late to properly taint everything from the
environment. So Perl gives up.

=item untie attempted while %d inner references still exist

(W) A copy of the object returned from C (or C) was still
valid when C was called.

=item Unrecognized character %s

(F) The Perl parser has no idea what to do with the specified character
in your Perl script (or eval). Perhaps you tried to run a compressed
script, a binary program, or a directory as a Perl program.

=item Unsupported function fork

(F) Your version of executable does not support forking.

Note that under some systems, like OS/2, there may be different flavors of
Perl executables, some of which may support fork, some not. Try changing
the name you call Perl by to C, C, and so on.

=item Use of "$$" to mean "${$}" is deprecated

(D) Perl versions before 5.004 misinterpreted any type marker followed
by "$" and a digit. For example, "$$0" was incorrectly taken to mean
"${$}0" instead of "${$0}". This bug is (mostly) fixed in Perl 5.004.

However, the developers of Perl 5.004 could not fix this bug completely,
because at least two widely-used modules depend on the old meaning of
"$$0" in a string. So Perl 5.004 still interprets "$$" in the
old (broken) way inside strings; but it generates this message as a
warning. And in Perl 5.005, this special treatment will cease.

=item Value of %s can be "0"; test with defined()

(W) In a conditional expression, you used , <*> (glob), C,
or C as a boolean value. Each of these constructs can return a
value of "0"; that would make the conditional expression false, which is
probably not what you intended. When using these constructs in conditional
expressions, test their values with the C operator.

=item Variable "%s" may be unavailable

(W) An inner (nested) I subroutine is inside a I
subroutine, and outside that is another subroutine; and the anonymous
(innermost) subroutine is referencing a lexical variable defined in
the outermost subroutine. For example:

sub outermost { my $a; sub middle { sub { $a } } }

If the anonymous subroutine is called or referenced (directly or
indirectly) from the outermost subroutine, it will share the variable
as you would expect. But if the anonymous subroutine is called or
referenced when the outermost subroutine is not active, it will see
the value of the shared variable as it was before and during the
*first* call to the outermost subroutine, which is probably not what
you want.

In these circumstances, it is usually best to make the middle
subroutine anonymous, using the C_{syntax. Perl has specific
support for shared variables in nested anonymous subroutines; a named
subroutine in between interferes with this feature.

=item Variable "%s" will not stay shared

(W) An inner (nested) I subroutine is referencing a lexical
variable defined in an outer subroutine.

When the inner subroutine is called, it will probably see the value of
the outer subroutine's variable as it was before and during the
*first* call to the outer subroutine; in this case, after the first
call to the outer subroutine is complete, the inner and outer
subroutines will no longer share a common value for the variable. In
other words, the variable will no longer be shared.

Furthermore, if the outer subroutine is anonymous and references a
lexical variable outside itself, then the outer and inner subroutines
will I share the given variable.

This problem can usually be solved by making the inner subroutine
anonymous, using the C_{syntax. When inner anonymous subs that
reference variables in outer subroutines are called or referenced,
they are automatically rebound to the current values of such
variables.

=item Warning: something's wrong

(W) You passed warn() an empty string (the equivalent of C) or
you called it with no args and C<$_> was empty.

=item Ill-formed logical name |%s| in prime_env_iter

(W) A warning peculiar to VMS. A logical name was encountered when preparing
to iterate over %ENV which violates the syntactic rules governing logical
names. Since it cannot be translated normally, it is skipped, and will not
appear in %ENV. This may be a benign occurrence, as some software packages
might directly modify logical name tables and introduce nonstandard names,
or it may indicate that a logical name table has been corrupted.

=item Got an error from DosAllocMem

(P) An error peculiar to OS/2. Most probably you're using an obsolete
version of Perl, and this should not happen anyway.

=item Malformed PERLLIB_PREFIX

(F) An error peculiar to OS/2. PERLLIB_PREFIX should be of the form

prefix1;prefix2

or

prefix1 prefix2

with nonempty prefix1 and prefix2. If C is indeed a prefix
of a builtin library search path, prefix2 is substituted. The error
may appear if components are not found, or are too long. See
"PERLLIB_PREFIX" in F.

=item PERL_SH_DIR too long

(F) An error peculiar to OS/2. PERL_SH_DIR is the directory to find the
C-shell in. See "PERL_SH_DIR" in F.

=item Process terminated by SIG%s

(W) This is a standard message issued by OS/2 applications, while *nix
applications die in silence. It is considered a feature of the OS/2
port. One can easily disable this by appropriate sighandlers, see
L. See also "Process terminated by SIGTERM/SIGINT"
in F.

=back

=head1 BUGS

If you find what you think is a bug, you might check the headers of
recently posted articles in the comp.lang.perl.misc newsgroup.
There may also be information at http://www.perl.com/perl/ , the Perl
Home Page.

If you believe you have an unreported bug, please run the B
program included with your release. Make sure you trim your bug down
to a tiny but sufficient test case. Your bug report, along with the
output of C, will be sent off to > to be
analysed by the Perl porting team.

=head1 SEE ALSO

The F file for exhaustive details on what changed.

The F file for how to build Perl. This file has been
significantly updated for 5.004, so even veteran users should
look through it.

The F file for general stuff.

The F file for copyright information.

=head1 HISTORY

Constructed by Tom Christiansen, grabbing material with permission
from innumerable contributors, with kibitzing by more than a few Perl
porters.

Last update: Wed May 14 11:14:09 EDT 1997}}}