PERLCYGWIN(1) Perl Programmers Reference Guide PERLCYGWIN(1)NAME
README.cygwin - Perl for Cygwin
SYNOPSIS
This document will help you configure, make, test and
install Perl on Cygwin. This document also describes fea
tures of Cygwin that will affect how Perl behaves at run
time.
NOTE: There are pre-built Perl packages available for Cyg
win and a version of Perl is provided on the Cygwin CD.
If you do not need to customize the configuration, con
sider using one of these packages:
http://cygutils.netpedia.net/
PREREQUISITES
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 environ
ment 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.
NOTE: At this point, minimal effort has been made to pro
vide 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 "http://cygutils.netpedia.net/". If there is signifi
cant demand, a patch kit can be developed to port back to
earlier Cygwin versions.
Cygwin Configuration
While building Perl some changes may be necessary to your
Cygwin setup so that Perl builds cleanly. These changes
are not required for normal Perl usage.
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
(ntea, ntsec, binary/text mounts). The only dependencies
come from hard-coded pathnames like "/usr/local". How
ever, your host system and Cygwin configuration will
affect Perl's runtime behavior (see the TEST entry else
where in this document).
""PATH""
Set the "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 "PATH".
nroff
If you do not have nroff (which is part of the groff
package), Configure will not prompt you to install man
pages.
Permissions
On WinNT with either the ntea or ntsec "CYGWIN" set
tings, directory and file permissions may not be set
correctly. Since the build process creates directo
ries and files, to be safe you may want to run a
`"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 Administra_
tors group will be owned by the 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 ntsec "CYGWIN"
setting, this is not an issue because it "corrects"
the ownership to what you would expect on a UNIX sys
tem.
CONFIGURE
The default options gathered by Configure with the assis
tance of hints/cygwin.sh will build a Perl that supports
dynamic loading (which requires a shared 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 Config
ure with -de. However, several useful customizations are
available.
Strip Binaries
It is possible to strip the EXEs and DLLs created by the
build process. The resulting binaries will be signifi
cantly smaller. If you want the binaries to be stripped,
you can either add a -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 hints/cygwin.sh and uncomment the relevant
variables near the end of the file.
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 "http://cygutils.netpe
dia.net/".
""-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
""-lgdbm"" (""use GDBM_File"")
GDBM is available for Cygwin. GDBM's ndbm/dbm compat
ibility feature also makes "NDBM_File" and "ODBM_File"
possible (although they add little extra value).
NOTE: The ndbm/dbm emulations only completely work on
NTFS partitions.
""-ldb"" (""use DB_File"")
BerkeleyDB is available for Cygwin. Some details can
be found in ext/DB_File/DB_File.pm.
NOTE: The BerkeleyDB library only completely works on
NTFS partitions.
""-lcygipc"" (""use IPC::SysV"")
A port of SysV IPC is available for Cygwin.
NOTE: This has not been extensively tested. In par
ticular, "d_semctl_semun" is undefined because it
fails a Configure test and on Win9x the shm*() func
tions seem to hang. It also creates a compile time
dependency because perl.h includes <sys/ipc.h> and
<sys/sem.h> (which will be required in the future when
compiling CPAN modules).
Configure-time Options
The 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.
""-Uusedl""
Undefining this symbol forces Perl to be compiled
statically.
""-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.
""-Dusemultiplicity""
Multiplicity is required when embedding Perl in a C
program and using more than one interpreter instance.
This works with the Cygwin port.
""-Duseperlio""
The PerlIO abstraction works with the Cygwin port.
""-Duse64bitint""
gcc supports 64-bit integers. However, several addi
tional long long functions are necessary to use them
within Perl ({strtol,strtoul}l). These are not yet
available with Cygwin.
""-Duselongdouble""
gcc supports long doubles (12 bytes). However, sev
eral additional long double math functions are neces
sary to use them within Perl
({atan2,cos,exp,floor,fmod,frexp,isnan,log,modf,pow,sin,sqrt}l,str_
told). These are not yet available with Cygwin.
""-Dusethreads""
POSIX threads are not yet implemented in Cygwin.
""-Duselargefiles""
Although Win32 supports large files, Cygwin currently
uses 32-bit integers for internal size and position
calculations.
Suspicious Warnings
You may see some messages during Configure that seem sus
picious.
dlsym()
ld2 is needed to build dynamic libraries, but it does
not exist when dlsym() checking occurs (it is not cre
ated until `"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.
Win9x and ""d_eofnblk""
Win9x does not correctly report "EOF" with a non-
blocking read on a closed pipe. You will see the fol
lowing 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.
Compiler/Preprocessor defines
The following error occurs because of the Cygwin
"#define" of "_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.
MAKE
Simply run make and wait:
make 2>&1 | tee log.make
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
ld2
During `"make"', ld2 will be created and installed in your
$installbin directory (where you said to put public exe
cutables). It does not wait until the `"make install"'
process to install the ld2 script, this is because the
remainder of the `"make"' refers to ld2 without fully
specifying its path and does this from multiple subdirec
tories. The assumption is that $installbin is in your
current "PATH". If this is not the case `"make"' will
fail at some point. If this happens, just manually copy
ld2 from the source directory to somewhere in your "PATH".
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 `"./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 fail
ures 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.
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
.{com,bat,exe} extension or begin with "#!", directories
are always readable and executable). On WinNT with the
ntea "CYGWIN" setting, the additional mode bits are stored
as extended file attributes. On WinNT with the ntsec
"CYGWIN" setting, permissions use the standard WinNT secu
rity 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)
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 "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
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
Tainting Checks
When Perl is running in taint mode, "$ENV{PATH}" is con
sidered 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 `"make
test"', 2 popups occur. During `"./perl harness"', 4 pop
ups occur. Also, these tests will fail:
Failed Test List of failed
------------------------------------
op/taint.t 1, 3, 31, 37
Alternatively, you can copy cygwin1.dll into the directory
where the tests run:
cp /bin/cygwin1.dll t
or one of the Windows system directories (although, this
is not recommended).
/etc/group
Cygwin does not require /etc/group, in which case the
op/grent.t test will be skipped. The check performed by
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
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.
Pathnames
Cygwin pathnames can be separated by forward (/) or
backward (\) slashes. They may also begin with drive
letters (C:) or Universal Naming Codes (//UNC). DOS
device names (aux, con, prn, com*, lpt?, nul) are
invalid as base filenames. However, they can be used
in extensions (e.g., 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 transla
tions applied to POSIX style pathnames).
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() func
tion to set binary mode on files that otherwise would
be treated as text. sysopen() with the "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 Cyg
win documentation.
.exe
The Cygwin stat(), lstat() and readlink() functions
make the .exe extension transparent by looking for
foo.exe when you ask for foo (unless a foo also
exists). Cygwin does not require a .exe extension,
but gcc adds it automatically when building a program.
However, when accessing an executable as a normal file
(e.g., cp in a makefile) the .exe is not transparent.
The install included with Cygwin automatically appends
a .exe when necessary.
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.
Miscellaneous
File locking using the "F_GETLK" command to fcntl() is
a stub that returns "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).
INSTALL
This will install Perl, including man pages.
make install | tee log.make-install
NOTE: If "STDERR" is redirected `"make install"' will not
prompt you to install perl into /usr/bin.
You may need to be Administrator to run `"make install"'.
If you are not, you must have write access to the directo
ries in question.
Information on installing the Perl documentation in HTML
format can be found in the INSTALL document.
MANIFEST
These are the files in the Perl release that contain ref
erences 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.
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
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
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)
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
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
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
BUGS
When make starts, it warns about overriding commands for
perlmain.o.
`"make clean"' does not remove library .def or .exe.stack_
dump files.
The ld2 script contains references to the source
directory. You should change these to $installbin after
`"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, `"dllwrap --export-all-symbols"' is
used to export global symbols. It might be better to gen
erate an explicit .def file (see makedef.pl). Also, DLLs
can now be build with `"gcc -shared"'.
AUTHORS
Charles Wilson <cwilson@ece.gatech.edu>, Eric Fifer
<egf7@columbia.edu>, alexander smishlajev <als@turn
here.com>, Steven Morlock <newspost@morlock.net>,
Sebastien Barre <Sebastien.Barre@utc.fr>, Teun Burgers
<burgers@ecn.nl>.
HISTORY
Last updated: 9 November 2000
2001-03-18 perl v5.6.1 PERLCYGWIN(1)
