A recent net or commercial release of Cygwin is required.
-At the time this document was last updated, Cygwin 1.3.12 was current.
+At the time this document was last updated, Cygwin 1.3.22 was current.
=head2 Cygwin Configuration
=item * C<-Uusemymalloc>
-By default Perl uses the malloc() included with the Perl source. If you
-want to force Perl to build with the system malloc() undefine this symbol.
+By default Perl uses the C<malloc()> included with the Perl source. If you
+want to force Perl to build with the system C<malloc()> undefine this symbol.
=item * C<-Uuseperlio>
-Undefining this symbol disables the PerlIO abstraction, which is now the
-default.
+Undefining this symbol disables the PerlIO abstraction, PerlIO is now the
+default, it is not recommended to disable PerlIO.
=item * C<-Dusemultiplicity>
=item * C<-Dmksymlinks>
Use this to build perl outside of the source tree. This works with Cygwin.
-Details can be found in the F<INSTALL> document.
+Details can be found in the F<INSTALL> document. This is the recommended
+way to build perl form sources.
=back
=item * I<dlsym()>
I<ld2> is needed to build dynamic libraries, but it does not exist
-when dlsym() checking occurs (it is not created until `C<make>' runs).
+when C<dlsym()> checking occurs (it is not created until `C<make>' runs).
You will see the following message:
- Checking whether your dlsym() needs a leading underscore ...
+ Checking whether your C<dlsym()> needs a leading underscore ...
ld2: not found
I can't compile and run the test program.
I'm guessing that dlsym doesn't need a leading underscore.
With NTFS (and CYGWIN=ntsec), there should be no problems even if
perl was built on FAT.
-=head2 fork() failures in io_* tests
+=head2 C<fork()> failures in io_* tests
-A fork() failure may result in the following tests failing:
+A C<fork()> failure may result in the following tests failing:
ext/IO/lib/IO/t/io_multihomed.t
ext/IO/lib/IO/t/io_sock.t
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 open() is determined by the mode of the mount that underlies
-the file. Perl provides a binmode() function to set binary mode on files
-that otherwise would be treated as text. sysopen() with the C<O_TEXT>
+mode for an C<open()> is determined by the mode of the mount that underlies
+the file. Perl provides a C<binmode()> function to set binary mode on files
+that otherwise would be treated as text. C<sysopen()> with the C<O_TEXT>
flag sets text mode on files that otherwise would be treated as binary:
sysopen(FOO, "bar", O_WRONLY|O_CREAT|O_TEXT)
-lseek(), tell() and sysseek() only work with files opened in binary mode.
+C<lseek()>, C<tell()> and C<sysseek()> only work with files opened in binary
+mode.
The text/binary issue is covered at length in the Cygwin documentation.
+=item * PerlIO
+
+PerlIO overrides the default Cygwin Text/Binary behaviour. A file will
+always treated as binary, regardless which mode of the mount it lives on,
+just like it is in UNIX. So CR/LF translation needs to be requested in
+either the C<open()> call like this:
+
+ open(FH, ">:crlf", "out.txt");
+
+which will do conversion from LF to CR/LF on the output, or in the
+environment settings (add this to your .bashrc):
+
+ export PERLIO=crlf
+
+which will pull in the crlf PerlIO layer which does LF -> CRLF conversion
+on every output generated by perl.
+
=item * F<.exe>
-The Cygwin stat(), lstat() and readlink() functions make the F<.exe>
+The Cygwin C<stat()>, C<lstat()> and C<readlink()> functions make the F<.exe>
extension transparent by looking for F<foo.exe> when you ask for F<foo>
(unless a F<foo> also exists). Cygwin does not require a F<.exe>
extension, but I<gcc> adds it automatically when building a program.
in a makefile) the F<.exe> is not transparent. The I<install> included
with Cygwin automatically appends a F<.exe> when necessary.
-=item * chown()
+=item * C<chown()>
-On WinNT chown() can change a file's user and group IDs. On Win9x chown()
+On WinNT C<chown()> can change a file's user and group IDs. On Win9x C<chown()>
is a no-op, although this is appropriate since there is no security model.
=item * Miscellaneous
-File locking using the C<F_GETLK> command to fcntl() is a stub that
+File locking using the C<F_GETLK> command to C<fcntl()> is a stub that
returns C<ENOSYS>.
-Win9x can not rename() an open file (although WinNT can).
+Win9x can not C<rename()> an open file (although WinNT can).
-The Cygwin chroot() implementation has holes (it can not restrict file
+The Cygwin C<chroot()> implementation has holes (it can not restrict file
access by native Win32 programs).
Inplace editing C<perl -i> of files doesn't work without doing a backup
of the file being edited C<perl -i.bak> because of windowish restrictions,
-therefore Perl adds the C<.bak> automatically if you use C<perl -i>
+therefore Perl adds the suffix C<.bak> automatically if you use C<perl -i>
without specifying a backup extension.
-Using fork() after loading multiple dlls may fail with an internal cygwin
+Using C<fork()> after loading multiple dlls may fail with an internal cygwin
error like the following:
C:\CYGWIN\BIN\PERL.EXE: *** couldn't allocate memory 0x10000(4128768) for 'C:\CYGWIN\LIB\PERL5\5.6.1\CYGWIN-MULTI\AUTO\SOCKET\SOCKET.DLL' alignment, Win32 error 8
Use the rebase utility to resolve the conflicting dll addresses. The
rebase package is included in the Cygwin netrelease. Use setup.exe from
-F<http://www.cygwin.com/setup.exe> to install it.
+F<http://www.cygwin.com/setup.exe> to install it and run rebaseall.
=back
=head1 BUGS ON CYGWIN
Support for swapping real and effective user and group IDs is incomplete.
-On WinNT Cygwin provides setuid(), seteuid(), setgid() and setegid().
+On WinNT Cygwin provides C<setuid()>, C<seteuid()>, C<setgid()> and C<setegid()>.
However, additional Cygwin calls for manipulating WinNT access tokens
and security contexts are required.