PERLCYGWIN
NAME SYNOPSIS PREREQUISITES CONFIGURE MAKE TEST INSTALL MANIFEST BUGS AUTHORS HISTORY
README .cygwin - Perl for Cygwin
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.
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
http://cygutils.netpedia.net/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
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 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 http://cygutils.netpedia.net/. If there is
significant 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. However, your host system and Cygwin configuration will affect Perl's runtime behavior (see `` TEST '').
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 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 `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 Administrators 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 system.
The default options gathered by Configure with the assistance 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
If you are willing to accept all the defaults run Configure 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 significantly 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.netpedia.net/.
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
ftp://ftp.franken.de/pub/win32/develop/gnuwin32/cygwin/porters/Okhapkin_Sergey/cw32crypt-dist-0.tgzNOTE: There are various export restrictions on DES implementations, see the glibc README for more details.
The MD5 port was done by Andy
GDBM is available for Cygwin. GDBM 's ndbm/dbm compatibility 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.
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.
IPC::SysV)
A port of SysV IPC is available for Cygwin.
NOTE: This has not been extensively tested. In particular, d_semctl_semun is undefined because it fails a Configure test and on Win9x the shm*() functions seem to hang. It also creates a compile time dependency because perl.h includes '' 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.
Undefining this symbol forces Perl to be compiled statically.
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.
Multiplicity is required when embedding Perl in a C program and using more than one interpreter instance. This works with the Cygwin port.
The PerlIO abstraction works with the Cygwin port.
gcc supports 64-bit integers. However, several additional long long functions are necessary to use them within Perl ({strtol,strtoul}l). These are not yet available with Cygwin.
gcc supports long doubles (12 bytes). However, several additional long double math functions are necessary to use them within Perl ({atan2,cos,exp,floor,fmod,frexp,isnan,log,modf,pow,sin,sqrt}l,strtold). These are not yet available with Cygwin.
POSIX threads are not yet implemented in Cygwin.
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 suspicious.
dlsym()
ld2 is needed to build dynamic libraries, but it does not exist when dlsym() checking occurs (it is not created until `make' runs). You will see the
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
WARNING: you can't distinguish between EOF and no data!
*** WHOA THERE!!! ***
The recommended value for $d_eofnblk on this machine was At least for consistency with WinNT, you should keep the recommended value.
Compiler/Preprocessor defines
The following error occurs because of the Cygwin
try.c: This failure does not seem to cause any problems.
Warnings
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 executables). 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 subdirectories. 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.
There are two steps to running the test
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 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.
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
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 security descriptors and access control lists. Without one
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
io/fs.t 4 op/stat.t 3
Filetime Granularity
On FAT partitions the filetime granularity is 2 seconds. The following test will
io/fs.t 18
Tainting Checks
When Perl is running in taint mode, $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
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 ...
op/taint.t 1, 3, 31, 37
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
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
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).
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 O_TEXT flag sets text mode on files that otherwise would be treated
lseek(), tell() and sysseek() only work with files opened in binary mode.
The text/binary issue is covered at length in the Cygwin 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).
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 directories in question.
Information on installing the Perl documentation in HTML format can be found in the INSTALL document.
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.
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
ext/SDBM_File/sdbm/sdbm.c
Perl Modules/Scripts
lib/Cwd.pm - hook to internal Cwd::cwd
lib/!ExtUtils?/MM_Cygwin.pm
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
When make starts, it warns about overriding commands for perlmain.o.
`make clean' does not remove library .def or .exe.stackdump 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 generate an explicit .def file (see makedef.pl). Also, DLLs can now be build with `gcc -shared'.
Charles Wilson
Last updated: 9 November 2000
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