perltodo.1

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

\&    sub bloop {
\&        print join (\*(Aq \*(Aq, No, strict, here), "!\en";
\&    }
.Ve
.PP
then \f(CW\*(C`use strict;\*(C'\fR isn't in force within the autoloaded subroutines. It would
be more consistent (and less surprising) to arrange for all lexical pragmas
in force at the _\|_END_\|_ block to be in force within each autoloaded subroutine.
.PP
There's a similar problem with SelfLoader.
.SH "Tasks that need a little sysadmin-type knowledge"
.IX Header "Tasks that need a little sysadmin-type knowledge"
Or if you prefer, tasks that you would learn from, and broaden your skills
base...
.Sh "make \s-1HTML\s0 install work"
.IX Subsection "make HTML install work"
There is an \f(CW\*(C`installhtml\*(C'\fR target in the Makefile. It's marked as
\&\*(L"experimental\*(R". It would be good to get this tested, make it work reliably, and
remove the \*(L"experimental\*(R" tag. This would include
.IP "1." 4
Checking that cross linking between various parts of the documentation works.
In particular that links work between the modules (files with \s-1POD\s0 in \fIlib/\fR)
and the core documentation (files in \fIpod/\fR)
.IP "2." 4
Work out how to split \f(CW\*(C`perlfunc\*(C'\fR into chunks, preferably one per function
group, preferably with general case code that could be used elsewhere.
Challenges here are correctly identifying the groups of functions that go
together, and making the right named external cross-links point to the right
page. Things to be aware of are \f(CW\*(C`\-X\*(C'\fR, groups such as \f(CW\*(C`getpwnam\*(C'\fR to
\&\f(CW\*(C`endservent\*(C'\fR, two or more \f(CW\*(C`=items\*(C'\fR giving the different parameter lists, such
as
.Sp
.Vb 3
\&    =item substr EXPR,OFFSET,LENGTH,REPLACEMENT
\&    =item substr EXPR,OFFSET,LENGTH
\&    =item substr EXPR,OFFSET
.Ve
.Sp
and different parameter lists having different meanings. (eg \f(CW\*(C`select\*(C'\fR)
.Sh "compressed man pages"
.IX Subsection "compressed man pages"
Be able to install them. This would probably need a configure test to see how
the system does compressed man pages (same directory/different directory?
same filename/different filename), as well as tweaking the \fIinstallman\fR script
to compress as necessary.
.Sh "Add a code coverage target to the Makefile"
.IX Subsection "Add a code coverage target to the Makefile"
Make it easy for anyone to run Devel::Cover on the core's tests. The steps
to do this manually are roughly
.IP "\(bu" 4
do a normal \f(CW\*(C`Configure\*(C'\fR, but include Devel::Cover as a module to install
(see \fI\s-1INSTALL\s0\fR for how to do this)
.IP "\(bu" 4

.Sp
.Vb 1
\&    make perl
.Ve
.IP "\(bu" 4

.Sp
.Vb 1
\&    cd t; HARNESS_PERL_SWITCHES=\-MDevel::Cover ./perl \-I../lib harness
.Ve
.IP "\(bu" 4
Process the resulting Devel::Cover database
.PP
This just give you the coverage of the \fI.pm\fRs. To also get the C level
coverage you need to
.IP "\(bu" 4
Additionally tell \f(CW\*(C`Configure\*(C'\fR to use the appropriate C compiler flags for
\&\f(CW\*(C`gcov\*(C'\fR
.IP "\(bu" 4

.Sp
.Vb 1
\&    make perl.gcov
.Ve
.Sp
(instead of \f(CW\*(C`make perl\*(C'\fR)
.IP "\(bu" 4
After running the tests run \f(CW\*(C`gcov\*(C'\fR to generate all the \fI.gcov\fR files.
(Including down in the subdirectories of \fIext/\fR
.IP "\(bu" 4
(From the top level perl directory) run \f(CW\*(C`gcov2perl\*(C'\fR on all the \f(CW\*(C`.gcov\*(C'\fR files
to get their stats into the cover_db directory.
.IP "\(bu" 4
Then process the Devel::Cover database
.PP
It would be good to add a single switch to \f(CW\*(C`Configure\*(C'\fR to specify that you
wanted to perform perl level coverage, and another to specify C level
coverage, and have \f(CW\*(C`Configure\*(C'\fR and the \fIMakefile\fR do all the right things
automatically.
.Sh "Make Config.pm cope with differences between built and installed perl"
.IX Subsection "Make Config.pm cope with differences between built and installed perl"
Quite often vendors ship a perl binary compiled with their (pay-for)
compilers.  People install a free compiler, such as gcc. To work out how to
build extensions, Perl interrogates \f(CW%Config\fR, so in this situation
\&\f(CW%Config\fR describes compilers that aren't there, and extension building
fails. This forces people into choosing between re-compiling perl themselves
using the compiler they have, or only using modules that the vendor ships.
.PP
It would be good to find a way teach \f(CW\*(C`Config.pm\*(C'\fR about the installation setup,
possibly involving probing at install time or later, so that the \f(CW%Config\fR in
a binary distribution better describes the installed machine, when the
installed machine differs from the build machine in some significant way.
.Sh "linker specification files"
.IX Subsection "linker specification files"
Some platforms mandate that you provide a list of a shared library's external
symbols to the linker, so the core already has the infrastructure in place to
do this for generating shared perl libraries. My understanding is that the
\&\s-1GNU\s0 toolchain can accept an optional linker specification file, and restrict
visibility just to symbols declared in that file. It would be good to extend
\&\fImakedef.pl\fR to support this format, and to provide a means within
\&\f(CW\*(C`Configure\*(C'\fR to enable it. This would allow Unix users to test that the
export list is correct, and to build a perl that does not pollute the global
namespace with private symbols.
.Sh "Cross-compile support"
.IX Subsection "Cross-compile support"
Currently \f(CW\*(C`Configure\*(C'\fR understands \f(CW\*(C`\-Dusecrosscompile\*(C'\fR option. This option
arranges for building \f(CW\*(C`miniperl\*(C'\fR for \s-1TARGET\s0 machine, so this \f(CW\*(C`miniperl\*(C'\fR is
assumed then to be copied to \s-1TARGET\s0 machine and used as a replacement of full
\&\f(CW\*(C`perl\*(C'\fR executable.
.PP
This could be done little differently. Namely \f(CW\*(C`miniperl\*(C'\fR should be built for
\&\s-1HOST\s0 and then full \f(CW\*(C`perl\*(C'\fR with extensions should be compiled for \s-1TARGET\s0.
This, however, might require extra trickery for \f(CW%Config:\fR we have one config
first for \s-1HOST\s0 and then another for \s-1TARGET\s0.  Tools like MakeMaker will be
mightily confused.  Having around two different types of executables and
libraries (\s-1HOST\s0 and \s-1TARGET\s0) makes life interesting for Makefiles and
shell (and Perl) scripts.  There is \f(CW$Config\fR{run}, normally empty, which
can be used as an execution wrapper.  Also note that in some
cross\-compilation/execution environments the \s-1HOST\s0 and the \s-1TARGET\s0 do
not see the same filesystem(s), the \f(CW$Config\fR{run} may need to do some
file/directory copying back and forth.
.Sh "roffitall"
.IX Subsection "roffitall"
Make \fIpod/roffitall\fR be updated by \fIpod/buildtoc\fR.
.SH "Tasks that need a little C knowledge"
.IX Header "Tasks that need a little C knowledge"
These tasks would need a little C knowledge, but don't need any specific
background or experience with \s-1XS\s0, or how the Perl interpreter works
.Sh "Exterminate PL_na!"
.IX Subsection "Exterminate PL_na!"
\&\f(CW\*(C`PL_na\*(C'\fR festers still in the darkest corners of various typemap files.
It needs to be exterminated, replaced by a local variable of type \f(CW\*(C`STRLEN\*(C'\fR.
.ie n .Sh "Modernize the order of directories in @INC"
.el .Sh "Modernize the order of directories in \f(CW@INC\fP"
.IX Subsection "Modernize the order of directories in @INC"
The way \f(CW@INC\fR is laid out by default, one cannot upgrade core (dual-life)
modules without overwriting files. This causes problems for binary
package builders.  One possible proposal is laid out in this
message:
<http://www.xray.mpe.mpg.de/mailing\-lists/perl5\-porters/2002\-04/msg02380.html>.
.Sh "\-Duse32bit*"
.IX Subsection "-Duse32bit*"
Natively 64\-bit systems need neither \-Duse64bitint nor \-Duse64bitall.
On these systems, it might be the default compilation mode, and there
is currently no guarantee that passing no use64bitall option to the
Configure process will build a 32bit perl. Implementing \-Duse32bit*
options would be nice for perl 5.12.
.Sh "Make it clear from \-v if this is the exact official release"
.IX Subsection "Make it clear from -v if this is the exact official release"
Currently perl from \f(CW\*(C`p4\*(C'\fR/\f(CW\*(C`rsync\*(C'\fR ships with a \fIpatchlevel.h\fR file that
usually defines one local patch, of the form \*(L"\s-1MAINT12345\s0\*(R" or \*(L"\s-1RC1\s0\*(R". The output
of perl \-v doesn't report that a perl isn't an official release, and this
information can get lost in bugs reports. Because of this, the minor version
isn't bumped up until \s-1RC\s0 time, to minimise the possibility of versions of perl
escaping that believe themselves to be newer than they actually are.
.PP
It would be useful to find an elegant way to have the \*(L"this is an interim
maintenance release\*(R" or \*(L"this is a release candidate\*(R" in the terse \-v output,
and have it so that it's easy for the pumpking to remove this just as the
release tarball is rolled up. This way the version pulled out of rsync would
always say \*(L"I'm a development release\*(R" and it would be safe to bump the
reported minor version as soon as a release ships, which would aid perl
developers.
.PP
This task is really about thinking of an elegant way to arrange the C source
such that it's trivial for the Pumpking to flag \*(L"this is an official release\*(R"
when making a tarball, yet leave the default source saying \*(L"I'm not the
official release\*(R".
.Sh "Profile Perl \- am I hot or not?"
.IX Subsection "Profile Perl - am I hot or not?"
The Perl source code is stable enough that it makes sense to profile it,
identify and optimise the hotspots. It would be good to measure the
performance of the Perl interpreter using free tools such as cachegrind,
gprof, and dtrace, and work to reduce the bottlenecks they reveal.
.PP
As part of this, the idea of \fIpp_hot.c\fR is that it contains the \fIhot\fR ops,
the ops that are most commonly used. The idea is that by grouping them, their
object code will be adjacent in the executable, so they have a greater chance
of already being in the \s-1CPU\s0 cache (or swapped in) due to being near another op
already in use.
.PP
Except that it's not clear if these really are the most commonly used ops. So
as part of exercising your skills with coverage and profiling tools you might
want to determine what ops \fIreally\fR are the most commonly used. And in turn
suggest evictions and promotions to achieve a better \fIpp_hot.c\fR.
.Sh "Allocate OPs from arenas"
.IX Subsection "Allocate OPs from arenas"
Currently all new \s-1OP\s0 structures are individually \fImalloc()\fRed and \fIfree()\fRd.
All \f(CW\*(C`malloc\*(C'\fR implementations have space overheads, and are now as fast as
custom allocates so it would both use less memory and less \s-1CPU\s0 to allocate
the various \s-1OP\s0 structures from arenas. The \s-1SV\s0 arena code can probably be
re-used for this.
.PP
Note that Configuring perl with \f(CW\*(C`\-Accflags=\-DPL_OP_SLAB_ALLOC\*(C'\fR will use
\&\fIPerl_Slab_alloc()\fR to pack optrees into a contiguous block, which is
probably superior to the use of \s-1OP\s0 arenas, esp. from a cache locality
standpoint.  See \*(L"Profile Perl \- am I hot or not?\*(R".
.Sh "Improve win32/wince.c"
.IX Subsection "Improve win32/wince.c"
Currently, numerous functions look virtually, if not completely,
identical in both \f(CW\*(C`win32/wince.c\*(C'\fR and \f(CW\*(C`win32/win32.c\*(C'\fR files, which can't
be good.
.Sh "Use secure \s-1CRT\s0 functions when building with \s-1VC8\s0 on Win32"
.IX Subsection "Use secure CRT functions when building with VC8 on Win32"
Visual \*(C+ 2005 (\s-1VC++\s0 8.x) deprecated a number of \s-1CRT\s0 functions on the basis
that they were \*(L"unsafe\*(R" and introduced differently named secure versions of
them as replacements, e.g. instead of writing
.PP
.Vb 1
\&    FILE* f = fopen(_\|_FILE_\|_, "r");
.Ve
.PP
one should now write
.PP
.Vb 2
\&    FILE* f;
\&    errno_t err = fopen_s(&f, _\|_FILE_\|_, "r");
.Ve
.PP
Currently, the warnings about these deprecations have been disabled by adding
\&\-D_CRT_SECURE_NO_DEPRECATE to the \s-1CFLAGS\s0. It would be nice to remove that
warning suppressant and actually make use of the new secure \s-1CRT\s0 functions.
.PP
There is also a similar issue with \s-1POSIX\s0 \s-1CRT\s0 function names like fileno having
been deprecated in favour of \s-1ISO\s0 \*(C+ conformant names like _fileno. These
warnings are also currently suppressed by adding \-D_CRT_NONSTDC_NO_DEPRECATE. It
might be nice to do as Microsoft suggest here too, although, unlike the secure
functions issue, there is presumably little or no benefit in this case.
.Sh "\fIstrcat()\fP, \fIstrcpy()\fP, \fIstrncat()\fP, \fIstrncpy()\fP, \fIsprintf()\fP, \fIvsprintf()\fP"
.IX Subsection "strcat(), strcpy(), strncat(), strncpy(), sprintf(), vsprintf()"
Maybe create a utility that checks after each libperl.a creation that
none of the above (nor \fIsprintf()\fR, \fIvsprintf()\fR, or *SHUDDER* \fIgets()\fR)
ever creep back to libperl.a.
.PP
.Vb 1
\&  nm libperl.a | ./miniperl \-alne \*(Aq$o = $F[0] if /:$/; print "$o $F[1]" if $F[0] eq "U" && $F[1] =~ /^(?:strn?c(?:at|py)|v?sprintf|gets)$/\*(Aq
.Ve
.PP
Note, of course, that this will only tell whether \fByour\fR platform
is using those naughty interfaces.
.Sh "\-D_FORTIFY_SOURCE=2, \-fstack\-protector"
.IX Subsection "-D_FORTIFY_SOURCE=2, -fstack-protector"
Recent glibcs support \f(CW\*(C`\-D_FORTIFY_SOURCE=2\*(C'\fR and recent gcc
(4.1 onwards?) supports \f(CW\*(C`\-fstack\-protector\*(C'\fR, both of which give
protection against various kinds of buffer overflow problems.
These should probably be used for compiling Perl whenever available,
Configure and/or hints files should be adjusted to probe for the
availability of these features and enable them as appropriate.
.SH "Tasks that need a knowledge of XS"
.IX Header "Tasks that need a knowledge of XS"
These tasks would need C knowledge, and roughly the level of knowledge of
the perl \s-1API\s0 that comes from writing modules that use \s-1XS\s0 to interface to
C.
.Sh "autovivification"
.IX Subsection "autovivification"
Make all autovivification consistent w.r.t \s-1LVALUE/RVALUE\s0 and strict/no strict;
.PP
This task is incremental \- even a little bit of work on it will help.
.Sh "Unicode in Filenames"
.IX Subsection "Unicode in Filenames"
chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open,
opendir, qx, readdir, readlink, rename, rmdir, stat, symlink, sysopen,
system, truncate, unlink, utime, \-X.  All these could potentially accept
Unicode filenames either as input or output (and in the case of system
and qx Unicode in general, as input or output to/from the shell).
Whether a filesystem \- an operating system pair understands Unicode in
filenames varies.
.PP
Known combinations that have some level of understanding include
Microsoft \s-1NTFS\s0, Apple \s-1HFS+\s0 (In Mac \s-1OS\s0 9 and X) and Apple \s-1UFS\s0 (in Mac
\&\s-1OS\s0 X), \s-1NFS\s0 v4 is rumored to be Unicode, and of course Plan 9.  How to
create Unicode filenames, what forms of Unicode are accepted and used
(\s-1UCS\-2\s0, \s-1UTF\-16\s0, \s-1UTF\-8\s0), what (if any) is the normalization form used,
and so on, varies.  Finding the right level of interfacing to Perl
requires some thought.  Remember that an \s-1OS\s0 does not implicate a
filesystem.
.PP
(The Windows \-C command flag \*(L"wide \s-1API\s0 support\*(R" has been at least
temporarily retired in 5.8.1, and the \-C has been repurposed, see
perlrun.)
.PP
Most probably the right way to do this would be this:
\&\*(L"Virtualize operating system access\*(R".
.ie n .Sh "Unicode in %ENV"
.el .Sh "Unicode in \f(CW%ENV\fP"
.IX Subsection "Unicode in %ENV"
Currently the \f(CW%ENV\fR entries are always byte strings.
See \*(L"Virtualize operating system access\*(R".
.Sh "Unicode and \fIglob()\fP"
.IX Subsection "Unicode and glob()"
Currently glob patterns and filenames returned from \fIFile::Glob::glob()\fR
are always byte strings.  See \*(L"Virtualize operating system access\*(R".
.Sh "Unicode and lc/uc operators"
.IX Subsection "Unicode and lc/uc operators"
Some built-in operators (\f(CW\*(C`lc\*(C'\fR, \f(CW\*(C`uc\*(C'\fR, etc.) behave differently, based on
what the internal encoding of their argument is. That should not be the
case. Maybe add a pragma to switch behaviour.
.Sh "use less 'memory'"
.IX Subsection "use less 'memory'"