perlcygwin.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.

want to force Perl to build with the system \f(CW\*(C`malloc()\*(C'\fR undefine this symbol.
.IP "\(bu" 4
\&\f(CW\*(C`\-Uuseperlio\*(C'\fR
.Sp
Undefining this symbol disables the PerlIO abstraction.  PerlIO is now the
default; it is not recommended to disable PerlIO.
.IP "\(bu" 4
\&\f(CW\*(C`\-Dusemultiplicity\*(C'\fR
.Sp
Multiplicity is required when embedding Perl in a C program and using
more than one interpreter instance.  This works with the Cygwin port.
.IP "\(bu" 4
\&\f(CW\*(C`\-Duse64bitint\*(C'\fR
.Sp
By default Perl uses 32 bit integers.  If you want to use larger 64
bit integers, define this symbol.
.IP "\(bu" 4
\&\f(CW\*(C`\-Duselongdouble\*(C'\fR
.Sp
\&\fIgcc\fR supports long doubles (12 bytes).  However, several additional
long double math functions are necessary to use them within Perl
(\fI{atan2, cos, exp, floor, fmod, frexp, isnan, log, modf, pow, sin, sqrt}l,
strtold\fR).
These are \fBnot\fR yet available with Cygwin.
.IP "\(bu" 4
\&\f(CW\*(C`\-Dusethreads\*(C'\fR
.Sp
\&\s-1POSIX\s0 threads are implemented in Cygwin, define this symbol if you want
a threaded perl.
.IP "\(bu" 4
\&\f(CW\*(C`\-Duselargefiles\*(C'\fR
.Sp
Cygwin uses 64\-bit integers for internal size and position calculations,
this will be correctly detected and defined by Configure.
.IP "\(bu" 4
\&\f(CW\*(C`\-Dmksymlinks\*(C'\fR
.Sp
Use this to build perl outside of the source tree.  This works with Cygwin.
Details can be found in the \fI\s-1INSTALL\s0\fR document.  This is the recommended
way to build perl from sources.
.Sh "Suspicious Warnings on Cygwin"
.IX Subsection "Suspicious Warnings on Cygwin"
You may see some messages during Configure that seem suspicious.
.IP "\(bu" 4
Win9x and \f(CW\*(C`d_eofnblk\*(C'\fR
.Sp
Win9x does not correctly report \f(CW\*(C`EOF\*(C'\fR with a non-blocking read on a
closed pipe.  You will see the following messages:
.Sp
.Vb 2
\&  But it also returns \-1 to signal EOF, so be careful!
\&  WARNING: you can\*(Aqt distinguish between EOF and no data!
\&
\&  *** WHOA THERE!!! ***
\&      The recommended value for $d_eofnblk on this machine was "define"!
\&      Keep the recommended value? [y]
.Ve
.Sp
At least for consistency with WinNT, you should keep the recommended
value.
.IP "\(bu" 4
Compiler/Preprocessor defines
.Sp
The following error occurs because of the Cygwin \f(CW\*(C`#define\*(C'\fR of
\&\f(CW\*(C`_LONG_DOUBLE\*(C'\fR:
.Sp
.Vb 2
\&  Guessing which symbols your C compiler and preprocessor define...
\&  try.c:<line#>: missing binary operator
.Ve
.Sp
This failure does not seem to cause any problems.  With older gcc
versions, \*(L"parse error\*(R" is reported instead of \*(L"missing binary
operator\*(R".
.SH "MAKE ON CYGWIN"
.IX Header "MAKE ON CYGWIN"
Simply run \fImake\fR and wait:
.PP
.Vb 1
\&  make 2>&1 | tee log.make
.Ve
.SH "TEST ON CYGWIN"
.IX Header "TEST ON CYGWIN"
There are two steps to running the test suite:
.PP
.Vb 1
\&  make test 2>&1 | tee log.make\-test
\&
\&  cd t; ./perl harness 2>&1 | tee ../log.harness
.Ve
.PP
The same tests are run both times, but more information is provided when
running as \f(CW\*(C`./perl harness\*(C'\fR.
.PP
Test results vary depending on your host system and your Cygwin
configuration.  If a test can pass in some Cygwin setup, it is always
attempted and explainable test failures are documented.  It is possible
for Perl to pass all the tests, but it is more likely that some tests
will fail for one of the reasons listed below.
.Sh "File Permissions on Cygwin"
.IX Subsection "File Permissions on Cygwin"
\&\s-1UNIX\s0 file permissions are based on sets of mode bits for
{read,write,execute} for each {user,group,other}.  By default Cygwin
only tracks the Win32 read-only attribute represented as the \s-1UNIX\s0 file
user write bit (files are always readable, files are executable if they
have a \fI.{com,bat,exe}\fR extension or begin with \f(CW\*(C`#!\*(C'\fR, directories are
always readable and executable).  On WinNT with the \fIntea\fR \f(CW\*(C`CYGWIN\*(C'\fR
setting, the additional mode bits are stored as extended file attributes.
On WinNT with the default \fIntsec\fR \f(CW\*(C`CYGWIN\*(C'\fR setting, permissions use the
standard WinNT security descriptors and access control lists. Without one of
these options, these tests will fail (listing not updated yet):
.PP
.Vb 12
\&  Failed Test           List of failed
\&  \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
\&  io/fs.t               5, 7, 9\-10
\&  lib/anydbm.t          2
\&  lib/db\-btree.t        20
\&  lib/db\-hash.t         16
\&  lib/db\-recno.t        18
\&  lib/gdbm.t            2
\&  lib/ndbm.t            2
\&  lib/odbm.t            2
\&  lib/sdbm.t            2
\&  op/stat.t             9, 20 (.tmp not an executable extension)
.Ve
.Sh "NDBM_File and ODBM_File do not work on \s-1FAT\s0 filesystems"
.IX Subsection "NDBM_File and ODBM_File do not work on FAT filesystems"
Do not use NDBM_File or ODBM_File on \s-1FAT\s0 filesystem.  They can be
built on a \s-1FAT\s0 filesystem, but many tests will fail:
.PP
.Vb 6
\& ../ext/NDBM_File/ndbm.t       13  3328    71   59  83.10%  1\-2 4 16\-71
\& ../ext/ODBM_File/odbm.t      255 65280    ??   ??       %  ??
\& ../lib/AnyDBM_File.t           2   512    12    2  16.67%  1 4
\& ../lib/Memoize/t/errors.t      0   139    11    5  45.45%  7\-11
\& ../lib/Memoize/t/tie_ndbm.t   13  3328     4    4 100.00%  1\-4
\& run/fresh_perl.t                          97    1   1.03%  91
.Ve
.PP
If you intend to run only on \s-1FAT\s0 (or if using AnyDBM_File on \s-1FAT\s0),
run Configure with the \-Ui_ndbm and \-Ui_dbm options to prevent
NDBM_File and ODBM_File being built.
.PP
With \s-1NTFS\s0 (and no CYGWIN=nontsec), there should be no problems even if
perl was built on \s-1FAT\s0.
.ie n .Sh """fork()"" failures in io_* tests"
.el .Sh "\f(CWfork()\fP failures in io_* tests"
.IX Subsection "fork() failures in io_* tests"
A \f(CW\*(C`fork()\*(C'\fR failure may result in the following tests failing:
.PP
.Vb 3
\&  ext/IO/lib/IO/t/io_multihomed.t
\&  ext/IO/lib/IO/t/io_sock.t
\&  ext/IO/lib/IO/t/io_unix.t
.Ve
.PP
See comment on fork in Miscellaneous below.
.SH "Specific features of the Cygwin port"
.IX Header "Specific features of the Cygwin port"
.Sh "Script Portability on Cygwin"
.IX Subsection "Script Portability on Cygwin"
Cygwin does an outstanding job of providing UNIX-like semantics on top of
Win32 systems.  However, in addition to the items noted above, there are
some differences that you should know about.  This is a very brief guide
to portability, more information can be found in the Cygwin documentation.
.IP "\(bu" 4
Pathnames
.Sp
Cygwin pathnames can be separated by forward (\fI/\fR) or backward (\fI\e\e\fR)
slashes.  They may also begin with drive letters (\fIC:\fR) or Universal
Naming Codes (\fI//UNC\fR).  \s-1DOS\s0 device names (\fIaux\fR, \fIcon\fR, \fIprn\fR,
\&\fIcom*\fR, \fIlpt?\fR, \fInul\fR) are invalid as base filenames.  However, they
can be used in extensions (e.g., \fIhello.aux\fR).  Names may contain all
printable characters except these:
.Sp
.Vb 1
\&  : * ? " < > |
.Ve
.Sp
File names are case insensitive, but case preserving.  A pathname that
contains a backslash or drive letter is a Win32 pathname (and not subject
to the translations applied to \s-1POSIX\s0 style pathnames).
.Sp
For conversion we have \f(CW\*(C`Cygwin::win_to_posix_path()\*(C'\fR and
\&\f(CW\*(C`Cygwin::posix_to_win_path()\*(C'\fR.
.Sp
Pathnames may not contain Unicode characters. \f(CW\*(C`Cygwin\*(C'\fR still uses the
\&\s-1ANSI\s0 \s-1API\s0 calls and no Unicode calls because of newlib deficiencies.
There's an unofficial unicode patch for cygwin at
\&\fIhttp://www.okisoft.co.jp/esc/utf8\-cygwin/\fR
.IP "\(bu" 4
Text/Binary
.Sp
When a file is opened it is in either text or binary mode.  In text mode
a file is subject to CR/LF/Ctrl\-Z translations.  With Cygwin, the default
mode for an \f(CW\*(C`open()\*(C'\fR is determined by the mode of the mount that underlies
the file. See \f(CW\*(C`Cygwin::is_binmount()\*(C'\fR. Perl provides a \f(CW\*(C`binmode()\*(C'\fR function
to set binary mode on files that otherwise would be treated as text.
\&\f(CW\*(C`sysopen()\*(C'\fR with the \f(CW\*(C`O_TEXT\*(C'\fR flag sets text mode on files that otherwise
would be treated as binary:
.Sp
.Vb 1
\&    sysopen(FOO, "bar", O_WRONLY|O_CREAT|O_TEXT)
.Ve
.Sp
\&\f(CW\*(C`lseek()\*(C'\fR, \f(CW\*(C`tell()\*(C'\fR and \f(CW\*(C`sysseek()\*(C'\fR only work with files opened in binary
mode.
.Sp
The text/binary issue is covered at length in the Cygwin documentation.
.IP "\(bu" 4
PerlIO
.Sp
PerlIO overrides the default Cygwin Text/Binary behaviour.  A file will
always be treated as binary, regardless of the mode of the mount it lives
on, just like it is in \s-1UNIX\s0.  So \s-1CR/LF\s0 translation needs to be requested in
either the \f(CW\*(C`open()\*(C'\fR call like this:
.Sp
.Vb 1
\&  open(FH, ">:crlf", "out.txt");
.Ve
.Sp
which will do conversion from \s-1LF\s0 to \s-1CR/LF\s0 on the output, or in the
environment settings (add this to your .bashrc):
.Sp
.Vb 1
\&  export PERLIO=crlf
.Ve
.Sp
which will pull in the crlf PerlIO layer which does \s-1LF\s0 \-> \s-1CRLF\s0 conversion
on every output generated by perl.
.IP "\(bu" 4
\&\fI.exe\fR
.Sp
The Cygwin \f(CW\*(C`stat()\*(C'\fR, \f(CW\*(C`lstat()\*(C'\fR and \f(CW\*(C`readlink()\*(C'\fR functions make the \fI.exe\fR
extension transparent by looking for \fIfoo.exe\fR when you ask for \fIfoo\fR
(unless a \fIfoo\fR also exists).  Cygwin does not require a \fI.exe\fR
extension, but \fIgcc\fR adds it automatically when building a program.
However, when accessing an executable as a normal file (e.g., \fIcp\fR
in a makefile) the \fI.exe\fR is not transparent.  The \fIinstall\fR included
with Cygwin automatically appends a \fI.exe\fR when necessary.
.IP "\(bu" 4
Cygwin vs. Windows process ids
.Sp
Cygwin processes have their own pid, which is different from the
underlying windows pid.  Most posix compliant Proc functions expect
the cygwin pid, but several Win32::Process functions expect the
winpid. E.g. \f(CW$$\fR is the cygwin pid of \fI/usr/bin/perl\fR, which is not
the winpid.  Use \f(CW\*(C`Cygwin::winpid_to_pid()\*(C'\fR and \f(CW\*(C`Cygwin::winpid_to_pid()\*(C'\fR
to translate between them.
.IP "\(bu" 4
Cygwin vs. Windows errors
.Sp
Under Cygwin, $^E is the same as $!.  When using Win32 \s-1API\s0 Functions,
use \f(CW\*(C`Win32::GetLastError()\*(C'\fR to get the last Windows error.
.IP "\(bu" 4
\&\f(CW\*(C`chown()\*(C'\fR
.Sp
On WinNT \f(CW\*(C`chown()\*(C'\fR can change a file's user and group IDs.  On Win9x \f(CW\*(C`chown()\*(C'\fR
is a no-op, although this is appropriate since there is no security model.
.IP "\(bu" 4
Miscellaneous
.Sp
File locking using the \f(CW\*(C`F_GETLK\*(C'\fR command to \f(CW\*(C`fcntl()\*(C'\fR is a stub that
returns \f(CW\*(C`ENOSYS\*(C'\fR.
.Sp
Win9x can not \f(CW\*(C`rename()\*(C'\fR an open file (although WinNT can).
.Sp
The Cygwin \f(CW\*(C`chroot()\*(C'\fR implementation has holes (it can not restrict file
access by native Win32 programs).
.Sp
Inplace editing \f(CW\*(C`perl \-i\*(C'\fR of files doesn't work without doing a backup
of the file being edited \f(CW\*(C`perl \-i.bak\*(C'\fR because of windowish restrictions,
therefore Perl adds the suffix \f(CW\*(C`.bak\*(C'\fR automatically if you use \f(CW\*(C`perl \-i\*(C'\fR
without specifying a backup extension.
.Sp
Using \f(CW\*(C`fork()\*(C'\fR after loading multiple dlls may fail with an internal cygwin
error like the following:
.Sp
.Vb 1
\&  C:\eCYGWIN\eBIN\ePERL.EXE: *** couldn\*(Aqt allocate memory 0x10000(4128768) for \*(AqC:\eCYGWIN\eLIB\ePERL5\e5.6.1\eCYGWIN\-MULTI\eAUTO\eSOCKET\eSOCKET.DLL\*(Aq alignment, Win32 error 8
\&
\&    200 [main] perl 377147 sync_with_child: child \-395691(0xB8) died before initialization with status code 0x1
\&   1370 [main] perl 377147 sync_with_child: *** child state child loading dlls
.Ve
.Sp
Use the rebase utility to resolve the conflicting dll addresses.  The
rebase package is included in the Cygwin netrelease.  Use setup.exe from
\&\fIhttp://www.cygwin.com/setup.exe\fR to install it and run rebaseall.
.Sh "Prebuilt methods:"
.IX Subsection "Prebuilt methods:"
.ie n .IP """Cwd::cwd""" 4
.el .IP "\f(CWCwd::cwd\fR" 4
.IX Item "Cwd::cwd"
Returns the current working directory.
.ie n .IP """Cygwin::pid_to_winpid""" 4
.el .IP "\f(CWCygwin::pid_to_winpid\fR" 4
.IX Item "Cygwin::pid_to_winpid"
Translates a cygwin pid to the corresponding Windows pid (which may or
may not be the same).
.ie n .IP """Cygwin::winpid_to_pid""" 4
.el .IP "\f(CWCygwin::winpid_to_pid\fR" 4
.IX Item "Cygwin::winpid_to_pid"
Translates a Windows pid to the corresponding cygwin pid (if any).
.ie n .IP """Cygwin::win_to_posix_path""" 4
.el .IP "\f(CWCygwin::win_to_posix_path\fR" 4
.IX Item "Cygwin::win_to_posix_path"