/IronPython_Main/Runtime/Tests/LinqDlrTests/testenv/perl/lib/pod/perlcygwin.pod

If you read this file _as_is_, just ignore the funny characters you

see. It is written in the POD format (see pod/perlpod.pod) which is

specially designed to be readable as is.



=head1 NAME



README.cygwin - Perl for Cygwin



=head1 SYNOPSIS



This document will help you configure, make, test and install Perl

on Cygwin.  This document also describes features of Cygwin that will

affect how Perl behaves at runtime.



B<NOTE:> There are pre-built Perl packages available for Cygwin and a

version of Perl is provided on the Cygwin CD.  If you do not need to

customize the configuration, consider using one of these packages:



  http://cygutils.netpedia.net/



=head1 PREREQUISITES



=head2 Cygwin = GNU+Cygnus+Windows (Don't leave UNIX without it)



The Cygwin tools are ports of the popular GNU development tools for Win32

platforms.  They run thanks to the Cygwin library which provides the UNIX

system calls and environment these programs expect.  More information

about this project can be found at:



  http://www.cygwin.com/



A recent net or commercial release of Cygwin is required.



At the time this document was last updated, Cygwin 1.1.5 was current.



B<NOTE:> At this point, minimal effort has been made to provide

compatibility with old (beta) Cygwin releases.  The focus has been to

provide a high quality release and not worry about working around old

bugs.  If you wish to use Perl with Cygwin B20.1 or earlier, consider

using perl5.005_03, which is available in source and binary form at

C<http://cygutils.netpedia.net/>.  If there is significant demand,

a patch kit can be developed to port back to earlier Cygwin versions.



=head2 Cygwin Configuration



While building Perl some changes may be necessary to your Cygwin setup so

that Perl builds cleanly.  These changes are B<not> required for normal

Perl usage.



B<NOTE:> The binaries that are built will run on all Win32 versions.

They do not depend on your host system (Win9x/WinME, WinNT/Win2K)

or your Cygwin configuration (I<ntea>, I<ntsec>, binary/text mounts).

The only dependencies come from hard-coded pathnames like C</usr/local>.

However, your host system and Cygwin configuration will affect Perl's

runtime behavior (see L</"TEST">).



=over 4



=item * C<PATH>



Set the C<PATH> environment variable so that Configure finds the Cygwin

versions of programs.  Any Windows directories should be removed or

moved to the end of your C<PATH>.



=item * I<nroff>



If you do not have I<nroff> (which is part of the I<groff> package),

Configure will B<not> prompt you to install I<man> pages.



=item * Permissions



On WinNT with either the I<ntea> or I<ntsec> C<CYGWIN> settings, directory

and file permissions may not be set correctly.  Since the build process

creates directories and files, to be safe you may want to run a `C<chmod

-R +w *>' on the entire Perl source tree.



Also, it is a well known WinNT "feature" that files created by a login

that is a member of the I<Administrators> group will be owned by the

I<Administrators> group.  Depending on your umask, you may find that you

can not write to files that you just created (because you are no longer

the owner).  When using the I<ntsec> C<CYGWIN> setting, this is not an

issue because it "corrects" the ownership to what you would expect on

a UNIX system.



=back



=head1 CONFIGURE



The default options gathered by Configure with the assistance of

F<hints/cygwin.sh> will build a Perl that supports dynamic loading

(which requires a shared F<libperl.dll>).



This will run Configure and keep a record:



  ./Configure 2>&1 | tee log.configure



If you are willing to accept all the defaults run Configure with B<-de>.

However, several useful customizations are available.



=head2 Strip Binaries



It is possible to strip the EXEs and DLLs created by the build process.

The resulting binaries will be significantly smaller.  If you want the

binaries to be stripped, you can either add a B<-s> option when Configure

prompts you,



  Any additional ld flags (NOT including libraries)? [none] -s

  Any special flags to pass to gcc to use dynamic linking? [none] -s

  Any special flags to pass to ld2 to create a dynamically loaded library?

  [none] -s



or you can edit F<hints/cygwin.sh> and uncomment the relevant variables

near the end of the file.



=head2 Optional Libraries



Several Perl functions and modules depend on the existence of

some optional libraries.  Configure will find them if they are

installed in one of the directories listed as being used for library

searches.  Pre-built packages for most of these are available at

C<http://cygutils.netpedia.net/>.



=over 4



=item * C<-lcrypt>



The crypt package distributed with Cygwin is a Linux compatible 56-bit

DES crypt port by Corinna Vinschen.



Alternatively, the crypt libraries in GNU libc have been ported to Cygwin.



The DES based Ultra Fast Crypt port was done by Alexey Truhan:



  ftp://ftp.franken.de/pub/win32/develop/gnuwin32/cygwin/porters/Okhapkin_Sergey/cw32crypt-dist-0.tgz



NOTE: There are various export restrictions on DES implementations,

see the glibc README for more details.



The MD5 port was done by Andy Piper:



  ftp://ftp.franken.de/pub/win32/develop/gnuwin32/cygwin/porters/Okhapkin_Sergey/libcrypt.tgz



=item * C<-lgdbm> (C<use GDBM_File>)



GDBM is available for Cygwin.  GDBM's ndbm/dbm compatibility feature

also makes C<NDBM_File> and C<ODBM_File> possible (although they add

little extra value).



NOTE: The ndbm/dbm emulations only completely work on NTFS partitions.



=item * C<-ldb> (C<use DB_File>)



BerkeleyDB is available for Cygwin.  Some details can be found in

F<ext/DB_File/DB_File.pm>.



NOTE: The BerkeleyDB library only completely works on NTFS partitions.



=item * C<-lcygipc> (C<use IPC::SysV>)



A port of SysV IPC is available for Cygwin.



NOTE: This has B<not> been extensively tested.  In particular,

C<d_semctl_semun> is undefined because it fails a Configure test

and on Win9x the I<shm*()> functions seem to hang.  It also creates

a compile time dependency because F<perl.h> includes F<<sys/ipc.h>>

and F<<sys/sem.h>> (which will be required in the future when compiling

CPAN modules).



=back



=head2 Configure-time Options



The F<INSTALL> document describes several Configure-time options.  Some of

these will work with Cygwin, others are not yet possible.  Also, some of

these are experimental.  You can either select an option when Configure

prompts you or you can define (undefine) symbols on the command line.



=over 4



=item * C<-Uusedl>



Undefining this symbol forces Perl to be compiled statically.



=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.



=item * C<-Dusemultiplicity>



Multiplicity is required when embedding Perl in a C program and using

more than one interpreter instance.  This works with the Cygwin port.



=item * C<-Duseperlio>



The PerlIO abstraction works with the Cygwin port.



=item * C<-Duse64bitint>



I<gcc> supports 64-bit integers.  However, several additional long long

functions are necessary to use them within Perl (I<{strtol,strtoul}l>).

These are B<not> yet available with Cygwin.



=item * C<-Duselongdouble>



I<gcc> supports long doubles (12 bytes).  However, several additional

long double math functions are necessary to use them within Perl

(I<{atan2,cos,exp,floor,fmod,frexp,isnan,log,modf,pow,sin,sqrt}l,strtold>).

These are B<not> yet available with Cygwin.



=item * C<-Dusethreads>



POSIX threads are B<not> yet implemented in Cygwin.



=item * C<-Duselargefiles>



Although Win32 supports large files, Cygwin currently uses 32-bit integers

for internal size and position calculations.



=back



=head2 Suspicious Warnings



You may see some messages during Configure that seem suspicious.



=over 4



=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).

You will see the following message:



  Checking whether your 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.



Since the guess is correct, this is not a problem.



=item * Win9x and C<d_eofnblk>



Win9x does not correctly report C<EOF> with a non-blocking read on a

closed pipe.  You will see the following messages:



  But it also returns -1 to signal EOF, so be careful!

  WARNING: you can't distinguish between EOF and no data!



  *** WHOA THERE!!! ***

      The recommended value for $d_eofnblk on this machine was "define"!

      Keep the recommended value? [y]



At least for consistency with WinNT, you should keep the recommended

value.



=item * Compiler/Preprocessor defines



The following error occurs because of the Cygwin C<#define> of

C<_LONG_DOUBLE>:



  Guessing which symbols your C compiler and preprocessor define...

  try.c:<line#>: parse error



This failure does not seem to cause any problems.



=back



=head1 MAKE



Simply run I<make> and wait:



  make 2>&1 | tee log.make



=head2 Warnings



Warnings like these are normal:



  warning: overriding commands for target <file>

  warning: ignoring old commands for target <file>



  dllwrap: no export definition file provided

  dllwrap: creating one, but that may not be what you want



=head2 ld2



During `C<make>', I<ld2> will be created and installed in your $installbin

directory (where you said to put public executables).  It does not

wait until the `C<make install>' process to install the I<ld2> script,

this is because the remainder of the `C<make>' refers to I<ld2> without

fully specifying its path and does this from multiple subdirectories.

The assumption is that $installbin is in your current C<PATH>.  If this

is not the case `C<make>' will fail at some point.  If this happens,

just manually copy I<ld2> from the source directory to somewhere in

your C<PATH>.



=head1 TEST



There are two steps to running the test suite:



  make test 2>&1 | tee log.make-test



  cd t;./perl harness 2>&1 | tee ../log.harness



The same tests are run both times, but more information is provided when

running as `C<./perl harness>'.



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.



=head2 File Permissions



UNIX 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 UNIX file

user write bit (files are always readable, files are executable if they

have a F<.{com,bat,exe}> extension or begin with C<#!>, directories are

always readable and executable).  On WinNT with the I<ntea> C<CYGWIN>

setting, the additional mode bits are stored as extended file attributes.

On WinNT with the I<ntsec> C<CYGWIN> setting, permissions use the standard

WinNT security descriptors and access control lists.  Without one of

these options, these tests will fail:



  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)



=head2 Hard Links



FAT partitions do not support hard links (whereas NTFS does), in which

case Cygwin implements link() by copying the file.  On remote (network)

drives Cygwin's stat() always sets C<st_nlink> to 1, so the link count

for remote directories and files is not available.  In either case,

these tests will fail:



  Failed Test           List of failed

  ------------------------------------

  io/fs.t               4

  op/stat.t             3



=head2 Filetime Granularity



On FAT partitions the filetime granularity is 2 seconds.  The following

test will fail:



  Failed Test           List of failed

  ------------------------------------

  io/fs.t               18



=head2 Tainting Checks



When Perl is running in taint mode, C<$ENV{PATH}> is considered tainted

and not used, so DLLs not in the default system directories will not

be found.  While the tests are running you will see warnings popup from

the system with messages like:



  Win9x

    Error Starting Program

    A required .DLL file, CYGWIN1.DLL, was not found



  WinNT

    perl.exe - Unable to Locate DLL

    The dynamic link library cygwin1.dll could not be found in the

      specified path ...



Just click OK and ignore them.  When running `C<make test>', 2 popups

occur.  During `C<./perl harness>', 4 popups occur.  Also, these tests

will fail:



  Failed Test           List of failed

  ------------------------------------

  op/taint.t            1, 3, 31, 37



Alternatively, you can copy F<cygwin1.dll> into the directory where the

tests run:



  cp /bin/cygwin1.dll t



or one of the Windows system directories (although, this is B<not>

recommended).



=head2 /etc/group



Cygwin does not require F</etc/group>, in which case the F<op/grent.t>

test will be skipped.  The check performed by F<op/grent.t> expects to

see entries that use the members field, otherwise this test will fail:



  Failed Test           List of failed

  ------------------------------------

  op/grent.t            1



=head2 Script Portability



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.



=over 4



=item * Pathnames



Cygwin pathnames can be separated by forward (F</>) or backward (F<\>)

slashes.  They may also begin with drive letters (F<C:>) or Universal

Naming Codes (F<//UNC>).  DOS device names (F<aux>, F<con>, F<prn>,

F<com*>, F<lpt?>, F<nul>) are invalid as base filenames.  However, they

can be used in extensions (e.g., F<hello.aux>).  Names may contain all

printable characters except these:



  : * ? " < > |



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 POSIX style pathnames).



=item * Text/Binary



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>

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.



The text/binary issue is covered at length in the Cygwin documentation.



=item * F<.exe>



The Cygwin stat(), lstat() and 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.

However, when accessing an executable as a normal file (e.g., I<cp>

in a makefile) the F<.exe> is not transparent.  The I<install> included

with Cygwin automatically appends a F<.exe> when necessary.



=item * chown()



On WinNT chown() can change a file's user and group IDs.  On Win9x 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

returns C<ENOSYS>.



Win9x can not rename() an open file (although WinNT can).



The Cygwin chroot() implementation has holes (it can not restrict file

access by native Win32 programs).



=back



=head1 INSTALL



This will install Perl, including I<man> pages.



  make install | tee log.make-install



NOTE: If C<STDERR> is redirected `C<make install>' will B<not> prompt

you to install I<perl> into F</usr/bin>.



You may need to be I<Administrator> to run `C<make install>'.  If you

are not, you must have write access to the directories in question.



Information on installing the Perl documentation in HTML format can be

found in the F<INSTALL> document.



=head1 MANIFEST



These are the files in the Perl release that contain references to Cygwin.

These very brief notes attempt to explain the reason for all conditional

code.  Hopefully, keeping this up to date will allow the Cygwin port to

be kept as clean as possible.



=over 4



=item Documentation



  INSTALL README.cygwin README.win32 MANIFEST

  Changes Changes5.005 Changes5.004 Changes5.6

  pod/perl.pod pod/perlport.pod pod/perlfaq3.pod

  pod/perldelta.pod pod/perl5004delta.pod pod/perl56delta.pod

  pod/perlhist.pod pod/perlmodlib.pod pod/buildtoc.PL pod/perltoc.pod



=item Build, Configure, Make, Install



  cygwin/Makefile.SHs

  cygwin/ld2.in

  cygwin/perlld.in

  ext/IPC/SysV/hints/cygwin.pl

  ext/NDBM_File/hints/cygwin.pl

  ext/ODBM_File/hints/cygwin.pl

  hints/cygwin.sh

  Configure             - help finding hints from uname,

                          shared libperl required for dynamic loading

  Makefile.SH           - linklibperl

  Porting/patchls       - cygwin in port list

  installman            - man pages with :: translated to .

  installperl           - install dll/ld2/perlld, install to pods

  makedepend.SH         - uwinfix



=item Tests



  t/io/tell.t           - binmode

  t/lib/b.t             - ignore Cwd from os_extras

  t/lib/glob-basic.t    - Win32 directory list access differs from read mode

  t/op/magic.t          - $^X/symlink WORKAROUND, s/.exe//

  t/op/stat.t           - no /dev, skip Win32 ftCreationTime quirk

                          (cache manager sometimes preserves ctime of file

                          previously created and deleted), no -u (setuid)



=item Compiled Perl Source



  EXTERN.h              - __declspec(dllimport)

  XSUB.h                - __declspec(dllexport)

  cygwin/cygwin.c       - os_extras (getcwd, spawn)

  perl.c                - os_extras

  perl.h                - binmode

  doio.c                - win9x can not rename a file when it is open

  pp_sys.c              - do not define h_errno, pp_system with spawn

  util.c                - use setenv



=item Compiled Module Source



  ext/POSIX/POSIX.xs    - tzname defined externally

  ext/SDBM_File/sdbm/pair.c

                        - EXTCONST needs to be redefined from EXTERN.h

  ext/SDBM_File/sdbm/sdbm.c

                        - binary open



=item Perl Modules/Scripts



  lib/Cwd.pm            - hook to internal Cwd::cwd

  lib/ExtUtils/MakeMaker.pm

                        - require MM_Cygwin.pm

  lib/ExtUtils/MM_Cygwin.pm

                        - canonpath, cflags, manifypods, perl_archive

  lib/File/Find.pm      - on remote drives stat() always sets st_nlink to 1

  lib/File/Spec/Unix.pm - preserve //unc

  lib/File/Temp.pm      - no directory sticky bit

  lib/perl5db.pl        - use stdin not /dev/tty

  utils/perldoc.PL      - version comment



=back



=head1 BUGS



When I<make> starts, it warns about overriding commands for F<perlmain.o>.



`C<make clean>' does not remove library F<.def> or F<.exe.stackdump>

files.



The I<ld2> script contains references to the source directory.  You should

change these to $installbin after `C<make install>'.



Support for swapping real and effective user and group IDs is incomplete.

On WinNT Cygwin provides setuid(), seteuid(), setgid() and setegid().

However, additional Cygwin calls for manipulating WinNT access tokens

and security contexts are required.



When building DLLs, `C<dllwrap --export-all-symbols>' is used to export

global symbols.  It might be better to generate an explicit F<.def> file

(see F<makedef.pl>).  Also, DLLs can now be build with `C<gcc -shared>'.



=head1 AUTHORS



Charles Wilson <cwilson@ece.gatech.edu>,

Eric Fifer <egf7@columbia.edu>,

alexander smishlajev <als@turnhere.com>,

Steven Morlock <newspost@morlock.net>,

Sebastien Barre <Sebastien.Barre@utc.fr>,

Teun Burgers <burgers@ecn.nl>.



=head1 HISTORY



Last updated: 9 November 2000