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perlwin32 - Perl under Windows


These are instructions for building Perl under Windows 7 and later.


Before you start, you should glance through the README file found in the top-level directory to which the Perl distribution was extracted. Make sure you read and understand the terms under which this software is being distributed.

Also make sure you read "BUGS AND CAVEATS" below for the known limitations of this port.

The INSTALL file in the perl top-level has much information that is only relevant to people building Perl on Unix-like systems. In particular, you can safely ignore any information that talks about "Configure".

You may also want to look at one other option for building a perl that will work on Windows: the README.cygwin file, which give a different set of rules to build a perl for Windows. This method will probably enable you to build a more Unix-compatible perl, but you will also need to download and use various other build-time and run-time support software described in that file.

This set of instructions is meant to describe a so-called "native" port of Perl to the Windows platform. This includes both 32-bit and 64-bit Windows operating systems. The resulting Perl requires no additional software to run (other than what came with your operating system). Currently, this port is capable of using one of the following compilers on the Intel x86 and x86_64 architectures:

Microsoft Visual C++    version 12.0 or later
Intel C++ Compiler      (experimental)
Gcc by        gcc version 3.4.5-5.3.0
Gcc by    gcc version 4.4.3 or later

Note that the last two of these are actually competing projects both delivering complete gcc toolchain for MS Windows:

Delivers gcc toolchain building 32-bit executables (which can be used both 32 and 64 bit Windows platforms)

Delivers gcc toolchain targeting both 64-bit Windows and 32-bit Windows platforms (despite the project name "mingw-w64" they are not only 64-bit oriented). They deliver the native gcc compilers and cross-compilers that are also supported by perl's makefile.

The Microsoft Visual C++ compilers are also now being given away free. They are available as "Visual C++ 2013-2022 Community Edition" and are the same compilers that ship with "Visual C++ 2013-2022 Professional".

Visual C++ 2013 is capable of targeting XP and Windows Server 2003 but the build host requirement is Windows 7/Windows Server 2012. For more details see and

The MinGW64 compiler is available at The latter is actually a cross-compiler targeting Win64. There's also a trimmed down compiler (no java, or gfortran) suitable for building perl available at:

NOTE: If you're using a 32-bit compiler to build perl on a 64-bit Windows operating system, then you should set the WIN64 environment variable to "undef". Also, the trimmed down compiler only passes tests when USE_ITHREADS *= define (as opposed to undef) and when the CFG *= Debug line is commented out.

This port fully supports MakeMaker (the set of modules that is used to build extensions to perl). Therefore, you should be able to build and install most extensions found in the CPAN sites. See "Usage Hints for Perl on Windows" below for general hints about this.

Setting Up Perl on Windows


You need a "make" program to build the sources. If you are using Visual C++, you can use nmake supplied with Visual C++. You may also use gmake instead of nmake. Builds using gcc need gmake. nmake is not supported for gcc builds. Parallel building is only supported with gmake, not nmake.

Command Shell

Use the default "cmd" shell that comes with Windows. Some versions of the popular 4DOS/NT shell have incompatibilities that may cause you trouble. If the build fails under that shell, try building again with the cmd shell.

Make sure the path to the build directory does not contain spaces. The build usually works in this circumstance, but some tests will fail.

Microsoft Visual C++

The nmake that comes with Visual C++ will suffice for building. Visual C++ requires that certain things be set up in the console before Visual C++ will successfully run. To make a console box be able to run the C compiler, you will need to beforehand, run vcvarsall.bat x86 to compile for x86-32 and for x86-64 vcvarsall.bat amd64. On a typical install of a Microsoft C++ compiler product, these batch files will already be in your PATH environment variable so you may just type them without an absolute path into your console. If you need to find the absolute path to the batch file, it is usually found somewhere like C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC. With some newer Microsoft C products (released after ~2004), the installer will put a shortcut in the start menu to launch a new console window with the console already set up for your target architecture (x86-32 or x86-64 or IA64). With the newer compilers, you may also use the older batch files if you choose so.

Microsoft Visual C++ 2013-2022 Community Edition

These free versions of Visual C++ 2013-2022 Professional contain the same compilers and linkers that ship with the full versions, and also contain everything necessary to build Perl.

These packages can be downloaded from

Install Visual C++ 2013-2022 Community, then setup your environment using, e.g.

C:\Program Files\Microsoft Visual Studio 12.0\Common7\Tools\vsvars32.bat

(assuming the default installation location was chosen).

Perl should now build using the win32/Makefile. You will need to edit that file to set CCTYPE to one of MSVC120-MSVC143 first.

Microsoft C++ Build Tools

There's also a standalone (IDE-less) version of the build tools mentioned above containing the MSVC compiler available for download from

This is also referred to as Build Tools for Visual Studio.


Perl can be compiled with gcc from MinGW (version 3.4.5 or later) or from MinGW64 (version 4.4.3 or later). It can be downloaded here:

You also need gmake. Usually it comes with MinGW but its executable may have a different name, such as mingw32-make.exe.

Note that the MinGW build currently fails with version 6.3.0 or later.

Note also that the C++ mode build currently fails with MinGW 3.4.5 and 4.7.2 or later, and with MinGW64 64-bit 6.3.0 or later.

Intel C++ Compiler

Experimental support for using Intel C++ Compiler has been added. Edit win32/Makefile and pick the correct CCTYPE for the Visual C that Intel C was installed into. Also uncomment __ICC to enable Intel C on Visual C support. To set up the build environment, from the Start Menu run IA-32 Visual Studio 20__ mode or Intel 64 Visual Studio 20__ mode as appropriate. Then run nmake as usual in that prompt box.

Only Intel C++ Compiler v12.1 has been tested. Other versions probably will work. Using Intel C++ Compiler instead of Visual C has the benefit of C99 compatibility which is needed by some CPAN XS modules, while maintaining compatibility with Visual C object code and Visual C debugging infrastructure unlike GCC.


Testing Perl on Windows

Type "gmake test" (or "nmake test"). This will run most of the tests from the testsuite (many tests will be skipped).

There should be no test failures.

If you build with Visual C++ 2013 then three tests currently may fail with Daylight Saving Time related problems: t/io/fs.t, cpan/HTTP-Tiny/t/110_mirror.t and lib/File/Copy.t. The failures are caused by bugs in the CRT in VC++ 2013 which are fixed in VC++2015 and later, as explained by Microsoft here: In the meantime, if you need fixed stat and utime functions then have a look at the CPAN distribution Win32::UTCFileTime.

If you build with Visual C++ 2015 or later then ext/XS-APItest/t/locale.t may crash (after all its tests have passed). This is due to a regression in the Universal CRT introduced in the Windows 10 April 2018 Update, and will be fixed in the May 2019 Update, as explained here:

If you build with certain versions (e.g. 4.8.1) of gcc from mingw then ext/POSIX/t/time.t may fail test 17 due to a known bug in those gcc builds: see

Some test failures may occur if you use a command shell other than the native "cmd.exe", or if you are building from a path that contains spaces. So don't do that.

If you are running the tests from a emacs shell window, you may see failures in op/stat.t. Run "gmake test-notty" in that case.

Furthermore, you should make sure that during make test you do not have any GNU tool packages in your path: some toolkits like Unixutils include some tools (type for instance) which override the Windows ones and makes tests fail. Remove them from your path while testing to avoid these errors.

To see the output of specific failing tests run the harness from the t directory:

# assuming you're starting from the win32 directory
cd ..\win32
.\perl harness <list of tests>

Please report any other failures as described under "BUGS AND CAVEATS".

Installation of Perl on Windows

Type "gmake install" ("nmake install"). This will put the newly built perl and the libraries under whatever INST_TOP points to in the Makefile. It will also install the pod documentation under $INST_TOP\$INST_VER\lib\pod and HTML versions of the same under $INST_TOP\$INST_VER\lib\pod\html.

To use the Perl you just installed you will need to add a new entry to your PATH environment variable: $INST_TOP\bin, e.g.

set PATH=c:\perl\bin;%PATH%

If you opted to uncomment INST_VER and INST_ARCH in the makefile then the installation structure is a little more complicated and you will need to add two new PATH components instead: $INST_TOP\$INST_VER\bin and $INST_TOP\$INST_VER\bin\$ARCHNAME, e.g.

set PATH=c:\perl\5.6.0\bin;c:\perl\5.6.0\bin\MSWin32-x86;%PATH%

Usage Hints for Perl on Windows

Environment Variables

The installation paths that you set during the build get compiled into perl, so you don't have to do anything additional to start using that perl (except add its location to your PATH variable).

If you put extensions in unusual places, you can set PERL5LIB to a list of paths separated by semicolons where you want perl to look for libraries. Look for descriptions of other environment variables you can set in perlrun.

You can also control the shell that perl uses to run system() and backtick commands via PERL5SHELL. See perlrun.

Perl does not depend on the registry, but it can look up certain default values if you choose to put them there unless disabled at build time with USE_NO_REGISTRY. On Perl process start Perl checks if HKEY_CURRENT_USER\Software\Perl and HKEY_LOCAL_MACHINE\Software\Perl exist. If the keys exists, they will be checked for remainder of the Perl process's run life for certain entries. Entries in HKEY_CURRENT_USER\Software\Perl override entries in HKEY_LOCAL_MACHINE\Software\Perl. One or more of the following entries (of type REG_SZ or REG_EXPAND_SZ) may be set in the keys:

lib-$]        version-specific standard library path to add to @INC
lib           standard library path to add to @INC
sitelib-$]    version-specific site library path to add to @INC
sitelib       site library path to add to @INC
vendorlib-$]  version-specific vendor library path to add to @INC
vendorlib     vendor library path to add to @INC
PERL*         fallback for all %ENV lookups that begin with "PERL"

Note the $] in the above is not literal. Substitute whatever version of perl you want to honor that entry, e.g. 5.6.0. Paths must be separated with semicolons, as usual on Windows.

File Globbing

By default, perl handles file globbing using the File::Glob extension, which provides portable globbing.

If you want perl to use globbing that emulates the quirks of DOS filename conventions, you might want to consider using File::DosGlob to override the internal glob() implementation. See File::DosGlob for details.

Using perl from the command line

If you are accustomed to using perl from various command-line shells found in UNIX environments, you will be less than pleased with what Windows offers by way of a command shell.

The crucial thing to understand about the Windows environment is that the command line you type in is processed twice before Perl sees it. First, your command shell (usually CMD.EXE) preprocesses the command line, to handle redirection, environment variable expansion, and location of the executable to run. Then, the perl executable splits the remaining command line into individual arguments, using the C runtime library upon which Perl was built.

It is particularly important to note that neither the shell nor the C runtime do any wildcard expansions of command-line arguments (so wildcards need not be quoted). Also, the quoting behaviours of the shell and the C runtime are rudimentary at best (and may, if you are using a non-standard shell, be inconsistent). The only (useful) quote character is the double quote ("). It can be used to protect spaces and other special characters in arguments.

The Windows documentation describes the shell parsing rules here: and the C runtime parsing rules here:

Here are some further observations based on experiments: The C runtime breaks arguments at spaces and passes them to programs in argc/argv. Double quotes can be used to prevent arguments with spaces in them from being split up. You can put a double quote in an argument by escaping it with a backslash and enclosing the whole argument within double quotes. The backslash and the pair of double quotes surrounding the argument will be stripped by the C runtime.

The file redirection characters "<", ">", and "|" can be quoted by double quotes (although there are suggestions that this may not always be true). Single quotes are not treated as quotes by the shell or the C runtime, they don't get stripped by the shell (just to make this type of quoting completely useless). The caret "^" has also been observed to behave as a quoting character, but this appears to be a shell feature, and the caret is not stripped from the command line, so Perl still sees it (and the C runtime phase does not treat the caret as a quote character).

Here are some examples of usage of the "cmd" shell:

This prints two doublequotes:

perl -e "print '\"\"' "

This does the same:

perl -e "print \"\\\"\\\"\" "

This prints "bar" and writes "foo" to the file "blurch":

perl -e "print 'foo'; print STDERR 'bar'" > blurch

This prints "foo" ("bar" disappears into nowhereland):

perl -e "print 'foo'; print STDERR 'bar'" 2> nul

This prints "bar" and writes "foo" into the file "blurch":

perl -e "print 'foo'; print STDERR 'bar'" 1> blurch

This pipes "foo" to the "less" pager and prints "bar" on the console:

perl -e "print 'foo'; print STDERR 'bar'" | less

This pipes "foo\nbar\n" to the less pager:

perl -le "print 'foo'; print STDERR 'bar'" 2>&1 | less

This pipes "foo" to the pager and writes "bar" in the file "blurch":

perl -e "print 'foo'; print STDERR 'bar'" 2> blurch | less

Discovering the usefulness of the "" shell on Windows 9x is left as an exercise to the reader :)

One particularly pernicious problem with the 4NT command shell for Windows is that it (nearly) always treats a % character as indicating that environment variable expansion is needed. Under this shell, it is therefore important to always double any % characters which you want Perl to see (for example, for hash variables), even when they are quoted.

Building Extensions

The Comprehensive Perl Archive Network (CPAN) offers a wealth of extensions, some of which require a C compiler to build. Look in for more information on CPAN.

Note that not all of the extensions available from CPAN may work in the Windows environment; you should check the information at before investing too much effort into porting modules that don't readily build.

Most extensions (whether they require a C compiler or not) can be built, tested and installed with the standard mantra:

perl Makefile.PL
$MAKE test
$MAKE install

where $MAKE is whatever 'make' program you have configured perl to use. Use "perl -V:make" to find out what this is. Some extensions may not provide a testsuite (so "$MAKE test" may not do anything or fail), but most serious ones do.

It is important that you use a supported 'make' program, and ensure knows about it.

Note that MakeMaker actually emits makefiles with different syntax depending on what 'make' it thinks you are using. Therefore, it is important that one of the following values appears in

make='nmake'	# MakeMaker emits nmake syntax
any other value	# MakeMaker emits generic make syntax
			    (e.g GNU make, or Perl make)

If the value doesn't match the 'make' program you want to use, edit to fix it.

If a module implements XSUBs, you will need one of the supported C compilers. You must make sure you have set up the environment for the compiler for command-line compilation before running perl Makefile.PL or any invocation of make.

If a module does not build for some reason, look carefully for why it failed, and report problems to the module author. If it looks like the extension building support is at fault, report that with full details of how the build failed using the GitHub issue tracker at

Command-line Wildcard Expansion

The default command shells on DOS descendant operating systems (such as they are) usually do not expand wildcard arguments supplied to programs. They consider it the application's job to handle that. This is commonly achieved by linking the application (in our case, perl) with startup code that the C runtime libraries usually provide. However, doing that results in incompatible perl versions (since the behavior of the argv expansion code differs depending on the compiler, and it is even buggy on some compilers). Besides, it may be a source of frustration if you use such a perl binary with an alternate shell that *does* expand wildcards.

Instead, the following solution works rather well. The nice things about it are 1) you can start using it right away; 2) it is more powerful, because it will do the right thing with a pattern like */*/*.c; 3) you can decide whether you do/don't want to use it; and 4) you can extend the method to add any customizations (or even entirely different kinds of wildcard expansion).

 C:\> copy con c:\perl\lib\
 # - emulate shell @ARGV expansion on shells that don't
 use File::DosGlob;
 @ARGV = map {
	      my @g = File::DosGlob::glob($_) if /[*?]/;
	      @g ? @g : $_;
	    } @ARGV;
 C:\> set PERL5OPT=-MWild
 C:\> perl -le "for (@ARGV) { print }" */*/perl*.c

Note there are two distinct steps there: 1) You'll have to create and put it in your perl lib directory. 2) You'll need to set the PERL5OPT environment variable. If you want argv expansion to be the default, just set PERL5OPT in your default startup environment.

If you are using the Visual C compiler, you can get the C runtime's command line wildcard expansion built into perl binary. The resulting binary will always expand unquoted command lines, which may not be what you want if you use a shell that does that for you. The expansion done is also somewhat less powerful than the approach suggested above.

Notes on 64-bit Windows

Windows .NET Server supports the LLP64 data model on the Intel Itanium architecture.

The LLP64 data model is different from the LP64 data model that is the norm on 64-bit Unix platforms. In the former, int and long are both 32-bit data types, while pointers are 64 bits wide. In addition, there is a separate 64-bit wide integral type, __int64. In contrast, the LP64 data model that is pervasive on Unix platforms provides int as the 32-bit type, while both the long type and pointers are of 64-bit precision. Note that both models provide for 64-bits of addressability.

64-bit Windows running on Itanium is capable of running 32-bit x86 binaries transparently. This means that you could use a 32-bit build of Perl on a 64-bit system. Given this, why would one want to build a 64-bit build of Perl? Here are some reasons why you would bother:

  • A 64-bit native application will run much more efficiently on Itanium hardware.

  • There is no 2GB limit on process size.

  • Perl automatically provides large file support when built under 64-bit Windows.

  • Embedding Perl inside a 64-bit application.

Running Perl Scripts

Perl scripts on UNIX use the "#!" (a.k.a "shebang") line to indicate to the OS that it should execute the file using perl. Windows has no comparable means to indicate arbitrary files are executables.

Instead, all available methods to execute plain text files on Windows rely on the file "extension". There are three methods to use this to execute perl scripts:

  1. There is a facility called "file extension associations". This can be manipulated via the two commands "assoc" and "ftype" that come standard with Windows. Type "ftype /?" for a complete example of how to set this up for perl scripts (Say what? You thought Windows wasn't perl-ready? :).

  2. Since file associations don't work everywhere, and there are reportedly bugs with file associations where it does work, the old method of wrapping the perl script to make it look like a regular batch file to the OS, may be used. The install process makes available the "pl2bat.bat" script which can be used to wrap perl scripts into batch files. For example:


    will create the file "FOO.BAT". Note "pl2bat" strips any .pl suffix and adds a .bat suffix to the generated file.

    If you use the 4DOS/NT or similar command shell, note that "pl2bat" uses the "%*" variable in the generated batch file to refer to all the command line arguments, so you may need to make sure that construct works in batch files. As of this writing, 4DOS/NT users will need a "ParameterChar = *" statement in their 4NT.INI file or will need to execute "setdos /p*" in the 4DOS/NT startup file to enable this to work.

  3. Using "pl2bat" has a few problems: the file name gets changed, so scripts that rely on $0 to find what they must do may not run properly; running "pl2bat" replicates the contents of the original script, and so this process can be maintenance intensive if the originals get updated often. A different approach that avoids both problems is possible.

    A script called "runperl.bat" is available that can be copied to any filename (along with the .bat suffix). For example, if you call it "foo.bat", it will run the file "foo" when it is executed. Since you can run batch files on Windows platforms simply by typing the name (without the extension), this effectively runs the file "foo", when you type either "foo" or "foo.bat". With this method, "foo.bat" can even be in a different location than the file "foo", as long as "foo" is available somewhere on the PATH. If your scripts are on a filesystem that allows symbolic links, you can even avoid copying "runperl.bat".

    Here's a diversion: copy "runperl.bat" to "runperl", and type "runperl". Explain the observed behavior, or lack thereof. :) Hint: .gnidnats llits er'uoy fi ,"lrepnur" eteled :tniH

Miscellaneous Things

A full set of HTML documentation is installed, so you should be able to use it if you have a web browser installed on your system.

perldoc is also a useful tool for browsing information contained in the documentation, especially in conjunction with a pager like less (recent versions of which have Windows support). You may have to set the PAGER environment variable to use a specific pager. "perldoc -f foo" will print information about the perl operator "foo".

One common mistake when using this port with a GUI library like Tk is assuming that Perl's normal behavior of opening a command-line window will go away. This isn't the case. If you want to start a copy of perl without opening a command-line window, use the wperl executable built during the installation process. Usage is exactly the same as normal perl on Windows, except that options like -h don't work (since they need a command-line window to print to).

If you find bugs in perl, you can report them to


Norton AntiVirus interferes with the build process, particularly if set to "AutoProtect, All Files, when Opened". Unlike large applications the perl build process opens and modifies a lot of files. Having the AntiVirus scan each and every one slows build the process significantly. Worse, with PERLIO=stdio the build process fails with peculiar messages as the virus checker interacts badly with miniperl.exe writing configure files (it seems to either catch file part written and treat it as suspicious, or virus checker may have it "locked" in a way which inhibits miniperl updating it). The build does complete with

set PERLIO=perlio

but that may be just luck. Other AntiVirus software may have similar issues.

A git GUI shell extension for Windows such as TortoiseGit will cause the build and later make test to run much slower since every file is checked for its git status as soon as it is created and/or modified. TortoiseGit doesn't cause any test failures or build problems unlike the antivirus software described above, but it does cause similar slowness. It is suggested to use Task Manager to look for background processes which use high CPU amounts during the building process.

Some of the built-in functions do not act exactly as documented in perlfunc, and a few are not implemented at all. To avoid surprises, particularly if you have had prior exposure to Perl in other operating environments or if you intend to write code that will be portable to other environments, see perlport for a reasonably definitive list of these differences.

Not all extensions available from CPAN may build or work properly in the Windows environment. See "Building Extensions".

Most socket() related calls are supported, but they may not behave as on Unix platforms. See perlport for the full list.

Signal handling may not behave as on Unix platforms (where it doesn't exactly "behave", either :). For instance, calling die() or exit() from signal handlers will cause an exception, since most implementations of signal() on Windows are severely crippled. Thus, signals may work only for simple things like setting a flag variable in the handler. Using signals under this port should currently be considered unsupported.

Please report detailed descriptions of any problems and solutions that you may find at <>, along with the output produced by perl -V.


The use of a camel with the topic of Perl is a trademark of O'Reilly and Associates, Inc. Used with permission.


Gary Ng <71564.1743@CompuServe.COM>
Gurusamy Sarathy <>
Nick Ing-Simmons <>
Jan Dubois <>
Steve Hay <>

This document is maintained by Jan Dubois.




This port was originally contributed by Gary Ng around 5.003_24, and borrowed from the Hip Communications port that was available at the time. Various people have made numerous and sundry hacks since then.

GCC/mingw32 support was added in 5.005 (Nick Ing-Simmons).

Support for PERL_OBJECT was added in 5.005 (ActiveState Tool Corp).

Support for fork() emulation was added in 5.6 (ActiveState Tool Corp).

Win9x support was added in 5.6 (Benjamin Stuhl).

Support for 64-bit Windows added in 5.8 (ActiveState Corp).

Last updated: 06 October 2021