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

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

specially designed to be readable as is.



=head1 NAME



perldos - Perl under DOS, W31, W95.



=head1 SYNOPSIS



These are instructions for building Perl under DOS (or w??), using

DJGPP v2.03 or later.  Under w95 long filenames are supported.



=head1 DESCRIPTION



Before you start, you should glance through the README file

found in the top-level directory where the Perl distribution

was extracted.  Make sure you read and understand the terms under

which this software is being distributed.



This port currently 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.



Detailed instructions on how to build and install perl extension

modules, including XS-type modules, is included.  See 'BUILDING AND

INSTALLING MODULES'.



=head2 Prerequisites



=over 4



=item DJGPP



DJGPP is a port of GNU C/C++ compiler and development tools to 32-bit,

protected-mode environment on Intel 32-bit CPUs running MS-DOS and compatible

operating systems, by DJ Delorie <dj@delorie.com> and friends.



For more details (FAQ), check out the home of DJGPP at:



        http://www.delorie.com/djgpp/



If you have questions about DJGPP, try posting to the DJGPP newsgroup:

comp.os.msdos.djgpp, or use the email gateway djgpp@delorie.com.



You can find the full DJGPP distribution on any SimTel.Net mirror all over

the world. Like:



        ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2*



You need the following files to build perl (or add new modules):



        v2/djdev203.zip

        v2/bnu2951b.zip

        v2gnu/gcc2952b.zip

        v2gnu/bsh204b.zip

        v2gnu/mak3791b.zip

        v2gnu/fil316b.zip

        v2gnu/sed302b.zip

        v2gnu/txt20b.zip

        v2gnu/dif272b.zip

        v2gnu/grep24b.zip

        v2gnu/shl112b.zip

        v2gnu/gawk303b.zip

        v2misc/csdpmi4b.zip



or possibly any newer version.



=item Pthreads



Thread support is not tested in this version of the djgpp perl.



=back



=head2 Shortcomings of Perl under DOS



Perl under DOS lacks some features of perl under UNIX because of

deficiencies in the UNIX-emulation, most notably:



=over 4



=item *



fork() and pipe()



=item *



some features of the UNIX filesystem regarding link count and file dates



=item *



in-place operation is a little bit broken with short filenames



=item *



sockets



=back



=head2 Building



=over 4



=item *



Unpack the source package F<perl5.6*.tar.gz> with djtarx. If you want

to use long file names under w95 and also to get Perl to pass all its

tests, don't forget to use



        set LFN=y

        set FNCASE=y



before unpacking the archive.



=item *



Create a "symlink" or copy your bash.exe to sh.exe in your C<($DJDIR)/bin>

directory.



        ln -s bash.exe sh.exe



[If you have the recommended version of bash for DJGPP, this is already

done for you.]



And make the C<SHELL> environment variable point to this F<sh.exe>:



        set SHELL=c:/djgpp/bin/sh.exe (use full path name!)



You can do this in F<djgpp.env> too. Add this line BEFORE any section

definition:



        +SHELL=%DJDIR%/bin/sh.exe



=item *



If you have F<split.exe> and F<gsplit.exe> in your path, then rename 

F<split.exe> to F<djsplit.exe>, and F<gsplit.exe> to F<split.exe>.

Copy or link F<gecho.exe> to F<echo.exe> if you don't have F<echo.exe>.

Copy or link F<gawk.exe> to F<awk.exe> if you don't have F<awk.exe>.



[If you have the recommended versions of djdev, shell utilities and

gawk, all these are already done for you, and you will not need to do

anything.]



=item *



Chdir to the djgpp subdirectory of perl toplevel and type the following

commands:



        set FNCASE=y

        configure.bat



This will do some preprocessing then run the Configure script for you.

The Configure script is interactive, but in most cases you just need to

press ENTER.  The "set" command ensures that DJGPP preserves the letter

case of file names when reading directories.  If you already issued this

set command when unpacking the archive, and you are in the same DOS

session as when you unpacked the archive, you don't have to issue the

set command again.  This command is necessary *before* you start to 

(re)configure or (re)build perl in order to ensure both that perl builds 

correctly and that building XS-type modules can succeed.  See the DJGPP 

info entry for "_preserve_fncase" for more information:



        info libc alphabetical _preserve_fncase



If the script says that your package is incomplete, and asks whether

to continue, just answer with Y (this can only happen if you don't use

long filenames or forget to issue "set FNCASE=y" first).



When Configure asks about the extensions, I suggest IO and Fcntl,

and if you want database handling then SDBM_File or GDBM_File

(you need to install gdbm for this one). If you want to use the

POSIX extension (this is the default), make sure that the stack

size of your F<cc1.exe> is at least 512kbyte (you can check this

with: C<stubedit cc1.exe>).



You can use the Configure script in non-interactive mode too.

When I built my F<perl.exe>, I used something like this:



        configure.bat -des



You can find more info about Configure's command line switches in

the F<INSTALL> file.



When the script ends, and you want to change some values in the

generated F<config.sh> file, then run



        sh Configure -S



after you made your modifications.



IMPORTANT: if you use this C<-S> switch, be sure to delete the CONFIG

environment variable before running the script:



        set CONFIG=



=item *



Now you can compile Perl. Type:



        make



=back



=head2 Testing



Type:



        make test



If you're lucky you should see "All tests successful". But there can be

a few failed subtests (less than 5 hopefully) depending on some external

conditions (e.g. some subtests fail under linux/dosemu or plain dos

with short filenames only).



=head2 Installation



Type:



        make install



This will copy the newly compiled perl and libraries into your DJGPP

directory structure. Perl.exe and the utilities go into C<($DJDIR)/bin>,

and the library goes under C<($DJDIR)/lib/perl5>. The pod documentation

goes under C<($DJDIR)/lib/perl5/pod>.



=head1 BUILDING AND INSTALLING MODULES





=head2 Prerequisites



For building and installing non-XS modules, all you need is a working

perl under DJGPP.  Non-XS modules do not require re-linking the perl

binary, and so are simpler to build and install.



XS-type modules do require re-linking the perl binary, because part of

an XS module is written in "C", and has to be linked together with the

perl binary to be executed.  This is required because perl under DJGPP

is built with the "static link" option, due to the lack of "dynamic

linking" in the DJGPP environment.



Because XS modules require re-linking of the perl binary, you need both

the perl binary distribution and the perl source distribution to build

an XS extension module.  In addition, you will have to have built your

perl binary from the source distribution so that all of the components

of the perl binary are available for the required link step.



=head2 Unpacking CPAN Modules



First, download the module package from CPAN (e.g., the "Comma Separated

Value" text package, Text-CSV-0.01.tar.gz).  Then expand the contents of

the package into some location on your disk.  Most CPAN modules are

built with an internal directory structure, so it is usually safe to

expand it in the root of your DJGPP installation.  Some people prefer to

locate source trees under /usr/src (i.e., C<($DJDIR)/usr/src>), but you may

put it wherever seems most logical to you, *EXCEPT* under the same

directory as your perl source code.  There are special rules that apply

to modules which live in the perl source tree that do not apply to most

of the modules in CPAN.



Unlike other DJGPP packages, which are normal "zip" files, most CPAN

module packages are "gzipped tarballs".  Recent versions of WinZip will

safely unpack and expand them, *UNLESS* they have zero-length files.  It

is a known WinZip bug (as of v7.0) that it will not extract zero-length

files.



From the command line, you can use the djtar utility provided with DJGPP

to unpack and expand these files.  For example:



        C:\djgpp>djtarx -v Text-CSV-0.01.tar.gz



This will create the new directory C<($DJDIR)/Text-CSV-0.01>, filling

it with the source for this module.



=head2 Building Non-XS Modules



To build a non-XS module, you can use the standard module-building

instructions distributed with perl modules.



    perl Makefile.PL

    make

    make test

    make install



This is sufficient because non-XS modules install only ".pm" files and

(sometimes) pod and/or man documentation.  No re-linking of the perl

binary is needed to build, install or use non-XS modules.



=head2 Building XS Modules



To build an XS module, you must use the standard module-building

instructions distributed with perl modules *PLUS* three extra

instructions specific to the DJGPP "static link" build environment.



    set FNCASE=y

    perl Makefile.PL

    make

    make perl

    make test

    make -f Makefile.aperl inst_perl MAP_TARGET=perl.exe

    make install



The first extra instruction sets DJGPP's FNCASE environment variable so

that the new perl binary which you must build for an XS-type module will

build correctly.  The second extra instruction re-builds the perl binary

in your module directory before you run "make test", so that you are

testing with the new module code you built with "make".  The third extra

instruction installs the perl binary from your module directory into the

standard DJGPP binary directory, C<($DJDIR)/bin>, replacing your

previous perl binary.



Note that the MAP_TARGET value *must* have the ".exe" extension or you

will not create a "perl.exe" to replace the one in C<($DJDIR)/bin>.



When you are done, the XS-module install process will have added information

to yout "perllocal" information telling that the perl binary has been replaced,

and what module was installed.  you can view this information at any time

by using the command:



        perl -S perldoc perllocal



=head1 AUTHOR



Laszlo Molnar, F<laszlo.molnar@eth.ericsson.se> [Installing/building perl]



Peter J. Farley III F<pjfarley@banet.net> [Building/installing modules]



=head1 SEE ALSO



perl(1).



=cut