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PERLCYGWIN(1) Perl Programmers Reference Guide PERLCYGWIN(1)
NAME
perlcygwin - Perl for Cygwin
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.
NOTE: There are pre-built Perl packages available for Cygwin and a
version of Perl is provided in the normal Cygwin install. If you do
not need to customize the configuration, consider using one of those
packages.
PREREQUISITES FOR COMPILING PERL ON CYGWIN
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:
<https://www.cygwin.com/>
A recent net or commercial release of Cygwin is required.
At the time this document was last updated, Cygwin 1.7.16 was current.
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 (WinXP/Win2K/Win7) or your Cygwin
configuration (binary/text mounts, cvgserver). 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").
o "PATH"
Set the "PATH" environment variable so that Configure finds the
Cygwin versions of programs. Any not-needed Windows directories
should be removed or moved to the end of your "PATH".
o nroff
If you do not have nroff (which is part of the groff package),
Configure will not prompt you to install man pages.
CONFIGURE PERL ON CYGWIN
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 cygperl5_16.dll).
This will run Configure and keep a record:
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 g++ to create a dynamically loaded
library?
[none] -s
Any special flags to pass to gcc to use dynamic linking? [none] -s
or you can edit hints/cygwin.sh and uncomment the relevant variables
near the end of the file.
Optional Libraries for Perl on Cygwin
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 from the Cygwin
installer.
o "-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.
As of libcrypt 1.3 (March 2016), you will need to install the
libcrypt-devel package for Configure to detect crypt().
o "-lgdbm_compat" ("use GDBM_File")
GDBM is available for Cygwin.
NOTE: The GDBM library only works on NTFS partitions.
o "-ldb" ("use DB_File")
BerkeleyDB is available for Cygwin.
NOTE: The BerkeleyDB library only completely works on NTFS
partitions.
o "cygserver" ("use 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 <sys/ipc.h> and
<sys/sem.h> (which will be required in the future when compiling
CPAN modules). CURRENTLY NOT SUPPORTED!
o "-lutil"
Included with the standard Cygwin netrelease is the inetutils
package which includes libutil.a.
o "-Uusedl"
Undefining this symbol forces Perl to be compiled statically.
o "-Dusemymalloc"
By default Perl does not use the "malloc()" included with the Perl
source, because it was slower and not entirely thread-safe. If you
want to force Perl to build with the old -Dusemymalloc define this.
o "-Uuseperlio"
Undefining this symbol disables the PerlIO abstraction. PerlIO is
now the default; it is not recommended to disable PerlIO.
o "-Dusemultiplicity"
Multiplicity is required when embedding Perl in a C program and
using more than one interpreter instance. This is only required
when you build a not-threaded perl with "-Uuseithreads".
o "-Uuse64bitint"
By default Perl uses 64 bit integers. If you want to use smaller
32 bit integers, define this symbol.
o "-Duselongdouble"
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 newlib, the
Cygwin libc.
o "-Uuseithreads"
Define this symbol if you want not-threaded faster perl.
o "-Duselargefiles"
Cygwin uses 64-bit integers for internal size and position
calculations, this will be correctly detected and defined by
Configure.
o "-Dmksymlinks"
Use this to build perl outside of the source tree. Details can be
found in the INSTALL document. This is the recommended way to
build perl from sources.
Suspicious Warnings on Cygwin
You may see some messages during Configure that seem suspicious.
o Win9x and "d_eofnblk"
Win9x does not correctly report "EOF" with a non-blocking read on a
closed pipe. You will see the following messages:
At least for consistency with WinNT, you should keep the
recommended value.
o 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#>: missing binary operator
This failure does not seem to cause any problems. With older gcc
versions, "parse error" is reported instead of "missing binary
operator".
MAKE ON CYGWIN
Simply run make and wait:
make 2>&1 | tee log.make
TEST ON CYGWIN
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 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 on Cygwin
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 default ntsec "CYGWIN" 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):
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
../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
If you intend to run only on FAT (or if using AnyDBM_File on FAT), run
Configure with the -Ui_ndbm and -Ui_dbm options to prevent NDBM_File
and ODBM_File being built.
With NTFS (and no CYGWIN=nontsec), there should be no problems even if
perl was built on FAT.
"fork()" failures in io_* tests
A "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
ext/IO/lib/IO/t/io_unix.t
See comment on fork in "Miscellaneous" below.
Specific features of the Cygwin port
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.
o Pathnames
Cygwin pathnames are separated by forward (/) slashes, Universal
Naming Codes (//UNC) are also supported Since cygwin-1.7 non-POSIX
pathnames are discouraged. Names may contain all printable
characters.
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,
but cygwin will warn you, so better convert them to POSIX.
For conversion we have "Cygwin::win_to_posix_path()" and
"Cygwin::posix_to_win_path()".
Since cygwin-1.7 pathnames are UTF-8 encoded.
o Text/Binary
Since cygwin-1.7 textmounts are deprecated and strongly
discouraged.
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. See "Cygwin::is_binmount"(). Perl
provides a "binmode()" function to set binary mode on files that
binary mode.
The text/binary issue is covered at length in the Cygwin
documentation.
o PerlIO
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 UNIX. So CR/LF translation
needs to be requested in either the "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.
o .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 program
included with Cygwin automatically appends a .exe when necessary.
o Cygwin vs. Windows process ids
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. $$ is the cygwin pid of /usr/bin/perl, which is not
the winpid. Use "Cygwin::pid_to_winpid()" and
"Cygwin::winpid_to_pid()" to translate between them.
o Cygwin vs. Windows errors
Under Cygwin, $^E is the same as $!. When using Win32 API
Functions, use "Win32::GetLastError()" to get the last Windows
error.
o rebase errors on fork or system
Using "fork()" or "system()" out to another perl after loading
multiple dlls may result on a DLL baseaddress conflict. The
internal cygwin error looks like like the following:
0 [main] perl 8916 child_info_fork::abort: data segment start:
parent (0xC1A000) != child(0xA6A000)
or:
183 [main] perl 3588 C:\cygwin\bin\perl.exe: *** fatal error -
address space is larger, e.g. stopping the MS Internet Explorer
might help.
Use the perlrebase or rebase utilities to resolve the conflicting
dll addresses. The rebase package is included in the Cygwin setup.
Use setup.exe from <https://cygwin.com/install.html> to install it.
1. kill all perl processes and run "perlrebase" or
2. kill all cygwin processes and services, start dash from cmd.exe
and run "rebaseall".
o "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.
o 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).
Inplace editing "perl -i" of files doesn't work without doing a
backup of the file being edited "perl -i.bak" because of windowish
restrictions, therefore Perl adds the suffix ".bak" automatically
if you use "perl -i" without specifying a backup extension.
Prebuilt methods:
"Cwd::cwd"
Returns the current working directory.
"Cygwin::pid_to_winpid"
Translates a cygwin pid to the corresponding Windows pid (which may
or may not be the same).
"Cygwin::winpid_to_pid"
Translates a Windows pid to the corresponding cygwin pid (if any).
"Cygwin::win_to_posix_path"
Translates a Windows path to the corresponding cygwin path
respecting the current mount points. With a second non-null
argument returns an absolute path. Double-byte characters will not
be translated.
"Cygwin::posix_to_win_path"
Translates a cygwin path to the corresponding cygwin path
respecting the current mount points. With a second non-null
argument returns an absolute path. Double-byte characters will not
be translated.
"Cygwin::mount_table()"
Returns an array of [mnt_dir, mnt_fsname, mnt_type, mnt_opts].
/cygdrive/e e: system binmode,noumount
"Cygwin::mount_flags"
Returns the mount type and flags for a specified mount point. A
comma-separated string of mntent->mnt_type (always "system" or
"user"), then the mntent->mnt_opts, where the first is always
"binmode" or "textmode".
system|user,binmode|textmode,exec,cygexec,cygdrive,mixed,
notexec,managed,nosuid,devfs,proc,noumount
If the argument is "/cygdrive", then just the volume mount
settings, and the cygdrive mount prefix are returned.
User mounts override system mounts.
$ perl -e 'print Cygwin::mount_flags "/usr/bin"'
system,binmode,cygexec
$ perl -e 'print Cygwin::mount_flags "/cygdrive"'
binmode,cygdrive,/cygdrive
"Cygwin::is_binmount"
Returns true if the given cygwin path is binary mounted, false if
the path is mounted in textmode.
"Cygwin::sync_winenv"
Cygwin does not initialize all original Win32 environment
variables. See the bottom of this page
<https://cygwin.com/cygwin-ug-net/setup-env.html> for "Restricted
Win32 environment".
Certain Win32 programs called from cygwin programs might need some
environment variable, such as e.g. ADODB needs
%COMMONPROGRAMFILES%. Call Cygwin::sync_winenv() to copy all Win32
environment variables to your process and note that cygwin will
warn on every encounter of non-POSIX paths.
INSTALL PERL ON CYGWIN
This will install Perl, including man pages.
make install 2>&1 | 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.
MANIFEST ON CYGWIN
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
dist/Cwd/Changes ext/Compress-Raw-Zlib/Changes
dist/Time-HiRes/Changes
ext/Compress-Raw-Zlib/README ext/Compress-Zlib/Changes
ext/DB_File/Changes ext/Encode/Changes ext/Sys-Syslog/Changes
ext/Win32API-File/Changes
lib/ExtUtils/CBuilder/Changes lib/ExtUtils/Changes
lib/ExtUtils/NOTES lib/ExtUtils/PATCHING lib/ExtUtils/README
lib/Net/Ping/Changes lib/Test/Harness/Changes
lib/Term/ANSIColor/ChangeLog lib/Term/ANSIColor/README
Build, Configure, Make, Install
cygwin/Makefile.SHs
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 Cross/Makefile-cross-SH
- linklibperl
Porting/patchls - cygwin in port list
installman - man pages with :: translated to .
installperl - install dll, install to 'pods'
makedepend.SH - uwinfix
regen_lib.pl - file permissions
NetWare/Makefile
plan9/mkfile
hints/uwin.sh
vms/descrip_mms.template
win32/Makefile
Tests
t/io/fs.t - no file mode checks if not ntsec
skip rename() check when not
check_case:relaxed
t/io/tell.t - binmode
t/lib/cygwin.t - builtin cygwin function tests
t/op/groups.t - basegroup has ID = 0
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)
t/op/taint.t - can't use empty path under Cygwin Perl
t/op/time.t - no tzset()
Compiled Perl Source
EXTERN.h - __declspec(dllimport)
XSUB.h - __declspec(dllexport)
cygwin/cygwin.c - os_extras (getcwd, spawn, and several
Cygwin:: functions)
perl.c - os_extras, -i.bak
perl.h - binmode
doio.c - win9x can not rename a file when it is open
pp_sys.c - do not define h_errno, init
_pwent_struct.pw_comment
util.c - use setenv
util.h - PERL_FILE_IS_ABSOLUTE macro
- Can't install via CPAN shell under Cygwin
ext/Compress-Raw-Zlib/zlib-src/zutil.h
- Cygwin is Unix-like and has vsnprintf
ext/Errno/Errno_pm.PL - Special handling for Win32 Perl under
Cygwin
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
ext/Sys/Syslog/Syslog.xs
- Cygwin has syslog.h
ext/Sys/Syslog/win32/compile.pl
- Convert paths to Windows paths
ext/Time-HiRes/HiRes.xs
- Various timers not available
ext/Time-HiRes/Makefile.PL
- Find w32api/windows.h
ext/Win32/Makefile.PL - Use various libraries under Cygwin
ext/Win32/Win32.xs - Child dir and child env under Cygwin
ext/Win32API-File/File.xs
- _open_osfhandle not implemented under
Cygwin
ext/Win32CORE/Win32CORE.c
- __declspec(dllexport)
Perl Modules/Scripts
ext/B/t/OptreeCheck.pm - Comment about stderr/stdout order under
Cygwin
ext/Digest-SHA/bin/shasum
- Use binary mode under Cygwin
ext/Sys/Syslog/win32/Win32.pm
- Convert paths to Windows paths
ext/Time-HiRes/HiRes.pm
- Comment about various timers not available
ext/Win32API-File/File.pm
- _open_osfhandle not implemented under
Cygwin
ext/Win32CORE/Win32CORE.pm
- History of Win32CORE under Cygwin
lib/Cwd.pm - hook to internal Cwd::cwd
lib/ExtUtils/CBuilder/Platform/cygwin.pm
- use gcc for ld, and link to libperl.dll.a
lib/ExtUtils/CBuilder.pm
- Cygwin is Unix-like
lib/ExtUtils/Install.pm - Install and rename issues under Cygwin
lib/ExtUtils/MM.pm - OS classifications
lib/ExtUtils/MM_Any.pm - Example for Cygwin
lib/ExtUtils/MakeMaker.pm
- require MM_Cygwin.pm
lib/ExtUtils/MM_Cygwin.pm
- canonpath, cflags, manifypods, perl_archive
lib/File/Fetch.pm - Comment about quotes using a Cygwin example
lib/File/Find.pm - on remote drives stat() always sets
st_nlink to 1
lib/File/Spec/Cygwin.pm - case_tolerant
lib/File/Spec/Unix.pm - preserve //unc
lib/File/Spec/Win32.pm - References a message on cygwin.com
lib/Pod/Perldoc/ToMan.pm - '-c' switch for pod2man
lib/Pod/Perldoc.pm - Use 'less' pager, and use .exe extension
lib/Term/ANSIColor.pm - Cygwin terminal info
lib/perl5db.pl - use stdin not /dev/tty
utils/perlbug.PL - Add CYGWIN environment variable to report
Perl Module Tests
dist/Cwd/t/cwd.t
ext/Compress-Zlib/t/14gzopen.t
ext/DB_File/t/db-btree.t
ext/DB_File/t/db-hash.t
ext/DB_File/t/db-recno.t
ext/DynaLoader/t/DynaLoader.t
ext/File-Glob/t/basic.t
ext/GDBM_File/t/gdbm.t
ext/POSIX/t/sysconf.t
ext/POSIX/t/time.t
ext/SDBM_File/t/sdbm.t
ext/Sys/Syslog/t/syslog.t
ext/Time-HiRes/t/HiRes.t
ext/Win32/t/Unicode.t
ext/Win32API-File/t/file.t
ext/Win32CORE/t/win32core.t
lib/AnyDBM_File.t
lib/Archive/Extract/t/01_Archive-Extract.t
lib/Archive/Tar/t/02_methods.t
lib/ExtUtils/t/Embed.t
lib/ExtUtils/t/eu_command.t
lib/ExtUtils/t/MM_Cygwin.t
lib/ExtUtils/t/MM_Unix.t
lib/File/Compare.t
lib/File/Copy.t
lib/File/Find/t/find.t
lib/File/Path.t
lib/File/Spec/t/crossplatform.t
lib/File/Spec/t/Spec.t
lib/Net/hostent.t
lib/Net/Ping/t/110_icmp_inst.t
lib/Net/Ping/t/500_ping_icmp.t
lib/Net/t/netrc.t
lib/Pod/Simple/t/perlcyg.pod
lib/Pod/Simple/t/perlcygo.txt
lib/Pod/Simple/t/perlfaq.pod
lib/Pod/Simple/t/perlfaqo.txt
lib/User/grent.t
lib/User/pwent.t
BUGS ON CYGWIN
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.
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>, Gerrit P.
Haase <gp@familiehaase.de>, Reini Urban <rurban@cpan.org>, Jan Dubois