in F<?:\JUST_ADD\view.exe>. This gives one an access to EMX's
F<.INF> docs as well (text form is available in F</emx/doc> in
-EMX's distribution).
+EMX's distribution). There is also a different viewer named xview.
-Note that if you have F<lynx.exe> installed, you can follow WWW links
+Note that if you have F<lynx.exe> or F<netscape.exe> installed, you can follow WWW links
from this document in F<.INF> format. If you have EMX docs installed
correctly, you can follow library links (you need to have C<view emxbook>
working by setting C<EMXBOOK> environment variable as it is described
=cut
-Contents
+Contents (This may be a little bit obsolete)
perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.
- NAME
- SYNOPSIS
- DESCRIPTION
- - Target
- - Other OSes
- - Prerequisites
- - Starting Perl programs under OS/2 (and DOS and...)
- - Starting OS/2 (and DOS) programs under Perl
- Frequently asked questions
- - I cannot run external programs
- - I cannot embed perl into my program, or use perl.dll from my program.
- - `` and pipe-open do not work under DOS.
- - Cannot start find.exe "pattern" file
- INSTALLATION
- - Automatic binary installation
- - Manual binary installation
- - Warning
- Accessing documentation
- - OS/2 .INF file
- - Plain text
- - Manpages
- - HTML
- - GNU info files
- - .PDF files
- - LaTeX docs
- BUILD
- - Prerequisites
- - Getting perl source
- - Application of the patches
- - Hand-editing
- - Making
- - Testing
- - Installing the built perl
- - a.out-style build
- Build FAQ
- - Some / became \ in pdksh.
- - 'errno' - unresolved external
- - Problems with tr
- - Some problem (forget which ;-)
- - Library ... not found
- - Segfault in make
- Specific (mis)features of EMX port
- - setpriority, getpriority
- - system()
- - extproc on the first line
- - Additional modules:
- - Prebuilt methods:
- - Misfeatures
- - Modifications
- Perl flavors
- - perl.exe
- - perl_.exe
- - perl__.exe
- - perl___.exe
- - Why strange names?
- - Why dynamic linking?
- - Why chimera build?
- ENVIRONMENT
- - PERLLIB_PREFIX
- - PERL_BADLANG
- - PERL_BADFREE
- - PERL_SH_DIR
- - TMP or TEMP
- Evolution
- - Priorities
- - DLL name mangling
- - Threading
- - Calls to external programs
- - Memory allocation
- AUTHOR
- SEE ALSO
-
+ NAME
+ SYNOPSIS
+ DESCRIPTION
+ - Target
+ - Other OSes
+ - Prerequisites
+ - Starting Perl programs under OS/2 (and DOS and...)
+ - Starting OS/2 (and DOS) programs under Perl
+ Frequently asked questions
+ - "It does not work"
+ - I cannot run external programs
+ - I cannot embed perl into my program, or use perl.dll from my
+ - `` and pipe-open do not work under DOS.
+ - Cannot start find.exe "pattern" file
+ INSTALLATION
+ - Automatic binary installation
+ - Manual binary installation
+ - Warning
+ Accessing documentation
+ - OS/2 .INF file
+ - Plain text
+ - Manpages
+ - HTML
+ - GNU info files
+ - PDF files
+ - LaTeX docs
+ BUILD
+ - The short story
+ - Prerequisites
+ - Getting perl source
+ - Application of the patches
+ - Hand-editing
+ - Making
+ - Testing
+ - Installing the built perl
+ - a.out-style build
+ Build FAQ
+ - Some / became \ in pdksh.
+ - 'errno' - unresolved external
+ - Problems with tr or sed
+ - Some problem (forget which ;-)
+ - Library ... not found
+ - Segfault in make
+ - op/sprintf test failure
+ Specific (mis)features of OS/2 port
+ - setpriority, getpriority
+ - system()
+ - extproc on the first line
+ - Additional modules:
+ - Prebuilt methods:
+ - Prebuilt variables:
+ - Misfeatures
+ - Modifications
+ - Identifying DLLs
+ - Centralized management of resources
+ Perl flavors
+ - perl.exe
+ - perl_.exe
+ - perl__.exe
+ - perl___.exe
+ - Why strange names?
+ - Why dynamic linking?
+ - Why chimera build?
+ ENVIRONMENT
+ - PERLLIB_PREFIX
+ - PERL_BADLANG
+ - PERL_BADFREE
+ - PERL_SH_DIR
+ - USE_PERL_FLOCK
+ - TMP or TEMP
+ Evolution
+ - Text-mode filehandles
+ - Priorities
+ - DLL name mangling: pre 5.6.2
+ - DLL name mangling: 5.6.2 and beyond
+ - DLL forwarder generation
+ - Threading
+ - Calls to external programs
+ - Memory allocation
+ - Threads
+ BUGS
+ AUTHOR
+ SEE ALSO
+
=head1 DESCRIPTION
=head2 Target
-The target is to make OS/2 the best supported platform for
+The target is to make OS/2 one of the best supported platform for
using/building/developing Perl and I<Perl applications>, as well as
make Perl the best language to use under OS/2. The secondary target is
to try to make this work under DOS and Win* as well (but not B<too> hard).
=item *
-Some *nix programs use fork() a lot, but currently fork() is not
-supported after I<use>ing dynamically loaded extensions.
+Some *nix programs use fork() a lot; with the mostly useful flavors of
+perl for OS/2 (there are several built simultaneously) this is
+supported; but some flavors do not support this (e.g., when Perl is
+called from inside REXX). Using fork() after
+I<use>ing dynamically loading extensions would not work with I<very> old
+versions of EMX.
=item *
You need a separate perl executable F<perl__.exe> (see L<perl__.exe>)
-to use PM code in your application (like the forthcoming Perl/Tk).
+if you want to use PM code in your application (as Perl/Tk or OpenGL
+Perl modules do) without having a text-mode window present.
+
+While using the standard F<perl.exe> from a text-mode window is possible
+too, I have seen cases when this causes degradation of the system stability.
+Using F<perl__.exe> avoids such a degradation.
=item *
There is no simple way to access WPS objects. The only way I know
-is via C<OS2::REXX> extension (see L<OS2::REXX>), and we do not have access to
+is via C<OS2::REXX> and C<SOM> extensions (see L<OS2::REXX>, L<Som>).
+However, we do not have access to
convenience methods of Object-REXX. (Is it possible at all? I know
-of no Object-REXX API.)
+of no Object-REXX API.) The C<SOM> extension (currently in alpha-text)
+may eventually remove this shortcoming; however, due to the fact that
+DII is not supported by the C<SOM> module, using C<SOM> is not as
+convenient as one would like it.
=back
=head2 Other OSes
Since OS/2 port of perl uses a remarkable EMX environment, it can
-run (and build extensions, and - possibly - be build itself) under any
+run (and build extensions, and - possibly - be built itself) under any
environment which can run EMX. The current list is DOS,
DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors,
only one works, see L<"perl_.exe">.
that under DOS for best results one should use RSX runtime, which
has much more functions working (like C<fork>, C<popen> and so on). In
fact RSX is required if there is no VCPI present. Note the
-RSX requires DPMI.
+RSX requires DPMI. Many implementations of DPMI are known to be very
+buggy, beware!
-Only the latest runtime is supported, currently C<0.9c>. Perl may run
+Only the latest runtime is supported, currently C<0.9d fix 03>. Perl may run
under earlier versions of EMX, but this is not tested.
One can get different parts of EMX from, say
- ftp://ftp.cdrom.com/pub/os2/emx09c/
- ftp://hobbes.nmsu.edu/os2/unix/emx09c/
+ http://www.leo.org/pub/comp/os/os2/leo/gnu/emx+gcc/
+ http://powerusersbbs.com/pub/os2/dev/ [EMX+GCC Development]
+ http://hobbes.nmsu.edu/pub/os2/dev/emx/v0.9d/
The runtime component should have the name F<emxrt.zip>.
-B<NOTE>. It is enough to have F<emx.exe>/F<rsx.exe> on your path. One
+B<NOTE>. When using F<emx.exe>/F<rsx.exe>, it is enough to have them on your path. One
does not need to specify them explicitly (though this
emx perl_.exe -de 0
Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
-The latest F<sh.exe> with DOS hooks is available at
+The latest F<sh.exe> with DOS hooks is available in
+
+ http://www.ilyaz.org/software/os2/
- ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
+as F<sh_dos.zip> or under similar names starting with C<sh>, C<pdksh> etc.
=item HPFS
-Perl does not care about file systems, but to install the whole perl
-library intact one needs a file system which supports long file names.
+Perl does not care about file systems, but the perl library contains
+many files with long names, so to install it intact one needs a file
+system which supports long file names.
Note that if you do not plan to build the perl itself, it may be
possible to fool EMX to truncate file names. This is not supported,
To start external programs with complicated command lines (like with
pipes in between, and/or quoting of arguments), Perl uses an external
-shell. With EMX port such shell should be named <sh.exe>, and located
+shell. With EMX port such shell should be named F<sh.exe>, and located
either in the wired-in-during-compile locations (usually F<F:/bin>),
or in configurable location (see L<"PERL_SH_DIR">).
-For best results use EMX pdksh. The soon-to-be-available standard
-binary (5.2.12?) runs under DOS (with L<RSX>) as well, meanwhile use
-the binary from
+For best results use EMX pdksh. The standard binary (5.2.14 or later) runs
+under DOS (with L<RSX>) as well, see
- ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
+ http://www.ilyaz.org/software/os2/
=back
perl foo.pl arg1 arg2 arg3
If you want to specify perl options C<-my_opts> to the perl itself (as
-opposed to to your program), use
+opposed to your program), use
perl -my_opts foo.pl arg1 arg2 arg3
Note that because of stupid OS/2 limitations the full path of the perl
script is not available when you use C<extproc>, thus you are forced to
-use C<-S> perl switch, and your script should be on path. As a plus
+use C<-S> perl switch, and your script should be on the C<PATH>. As a plus
side, if you know a full path to your script, you may still start it
with
*nixish shell (like F<sh.exe> supplied in the binary distribution),
you need to follow the syntax specified in L<perlrun/"Switches">.
+Note that B<-S> switch supports scripts with additional extensions
+F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well.
+
=head2 Starting OS/2 (and DOS) programs under Perl
This is what system() (see L<perlfunc/system>), C<``> (see
L<"Frequently asked questions">), and perl should be able to find it
(see L<"PERL_SH_DIR">).
-The only cases when the shell is not used is the multi-argument
-system() (see L<perlfunc/system>)/exec() (see L<perlfunc/exec>), and
-one-argument version thereof without redirection and shell
-meta-characters.
+The cases when the shell is used are:
+
+=over
+
+=item 1
+
+One-argument system() (see L<perlfunc/system>), exec() (see L<perlfunc/exec>)
+with redirection or shell meta-characters;
+
+=item 2
+
+Pipe-open (see L<perlfunc/open>) with the command which contains redirection
+or shell meta-characters;
+
+=item 3
+
+Backticks C<``> (see L<perlop/"I/O Operators">) with the command which contains
+redirection or shell meta-characters;
+
+=item 4
+
+If the executable called by system()/exec()/pipe-open()/C<``> is a script
+with the "magic" C<#!> line or C<extproc> line which specifies shell;
+
+=item 5
+
+If the executable called by system()/exec()/pipe-open()/C<``> is a script
+without "magic" line, and C<$ENV{EXECSHELL}> is set to shell;
+
+=item 6
+
+If the executable called by system()/exec()/pipe-open()/C<``> is not
+found (is not this remark obsolete?);
+
+=item 7
+
+For globbing (see L<perlfunc/glob>, L<perlop/"I/O Operators">)
+(obsolete? Perl uses builtin globbing nowadays...).
+
+=back
+
+For the sake of speed for a common case, in the above algorithms
+backslashes in the command name are not considered as shell metacharacters.
+
+Perl starts scripts which begin with cookies
+C<extproc> or C<#!> directly, without an intervention of shell. Perl uses the
+same algorithm to find the executable as F<pdksh>: if the path
+on C<#!> line does not work, and contains C</>, then the directory
+part of the executable is ignored, and the executable
+is searched in F<.> and on C<PATH>. To find arguments for these scripts
+Perl uses a different algorithm than F<pdksh>: up to 3 arguments are
+recognized, and trailing whitespace is stripped.
+
+If a script
+does not contain such a cooky, then to avoid calling F<sh.exe>, Perl uses
+the same algorithm as F<pdksh>: if C<$ENV{EXECSHELL}> is set, the
+script is given as the first argument to this command, if not set, then
+C<$ENV{COMSPEC} /c> is used (or a hardwired guess if C<$ENV{COMSPEC}> is
+not set).
+
+When starting scripts directly, Perl uses exactly the same algorithm as for
+the search of script given by B<-S> command-line option: it will look in
+the current directory, then on components of C<$ENV{PATH}> using the
+following order of appended extensions: no extension, F<.cmd>, F<.btm>,
+F<.bat>, F<.pl>.
+
+Note that Perl will start to look for scripts only if OS/2 cannot start the
+specified application, thus C<system 'blah'> will not look for a script if
+there is an executable file F<blah.exe> I<anywhere> on C<PATH>. In
+other words, C<PATH> is essentially searched twice: once by the OS for
+an executable, then by Perl for scripts.
+
+Note also that executable files on OS/2 can have an arbitrary extension,
+but F<.exe> will be automatically appended if no dot is present in the name.
+The workaround is as simple as that: since F<blah.> and F<blah> denote the
+same file (at list on FAT and HPFS file systems), to start an executable residing in file F<n:/bin/blah> (no
+extension) give an argument C<n:/bin/blah.> (dot appended) to system().
+
+Perl will start PM programs from VIO (=text-mode) Perl process in a
+separate PM session;
+the opposite is not true: when you start a non-PM program from a PM
+Perl process, Perl would not run it in a separate session. If a separate
+session is desired, either ensure
+that shell will be used, as in C<system 'cmd /c myprog'>, or start it using
+optional arguments to system() documented in C<OS2::Process> module. This
+is considered to be a feature.
=head1 Frequently asked questions
+=head2 "It does not work"
+
+Perl binary distributions come with a F<testperl.cmd> script which tries
+to detect common problems with misconfigured installations. There is a
+pretty large chance it will discover which step of the installation you
+managed to goof. C<;-)>
+
=head2 I cannot run external programs
=over 4
-=item
+=item *
Did you run your programs with C<-w> switch? See
L<Starting OS/2 (and DOS) programs under Perl>.
-=item
+=item *
Do you try to run I<internal> shell commands, like C<`copy a b`>
(internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
=item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
-If not, you need to build a stand-alone DLL for perl. Contact me, I
-did it once. Sockets would not work, as a lot of other stuff.
+Well, nowadays Perl DLL should be usable from a differently compiled
+program too... If you can run Perl code from REXX scripts (see
+L<OS2::REXX>), then there are some other aspect of interaction which
+are overlooked by the current hackish code to support
+differently-compiled principal programs.
+
+If everything else fails, you need to build a stand-alone DLL for
+perl. Contact me, I did it once. Sockets would not work, as a lot of
+other stuff.
=item Did you use L<ExtUtils::Embed>?
-I had reports it does not work. Somebody would need to fix it.
+Some time ago I had reports it does not work. Nowadays it is checked
+in the Perl test suite, so grep F<./t> subdirectory of the build tree
+(as well as F<*.t> files in the F<./lib> subdirectory) to find how it
+should be done "correctly".
=back
=head2 Cannot start C<find.exe "pattern" file>
+The whole idea of the "standard C API to start applications" is that
+the forms C<foo> and C<"foo"> of program arguments are completely
+interchangable. F<find> breaks this paradigm;
+
+ find "pattern" file
+ find pattern file
+
+are not equivalent; F<find> cannot be started directly using the above
+API. One needs a way to surround the doublequotes in some other
+quoting construction, necessarily having an extra non-Unixish shell in
+between.
+
Use one of
system 'cmd', '/c', 'find "pattern" file';
This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
C<perl.exe>, but this is a price to pay if you want to use
-non-conforming program. In fact F<find.exe> cannot be started at all
-using C library API only. Otherwise the following command-lines were
-equivalent:
-
- find "pattern" file
- find pattern file
+non-conforming program.
=head1 INSTALLATION
=head2 Automatic binary installation
-The most convenient way of installing perl is via perl installer
+The most convenient way of installing a binary distribution of perl is via perl installer
F<install.exe>. Just follow the instructions, and 99% of the
installation blues would go away.
emxrev
-A folder is created on your desktop which contains some useful
-objects.
+Binary installer also creates a folder on your desktop with some useful
+objects. If you need to change some aspects of the work of the binary
+installer, feel free to edit the file F<Perl.pkg>. This may be useful
+e.g., if you need to run the installer many times and do not want to
+make many interactive changes in the GUI.
B<Things not taken care of by automatic binary installation:>
While most important values in this file I<are> updated by the binary
installer, some of them may need to be hand-edited. I know no such
-data, please keep me informed if you find one.
+data, please keep me informed if you find one. Moreover, manual
+changes to the installed version may need to be accompanied by an edit
+of this file.
=back
need to know where to extract the files. You need also to manually
change entries in F<Config.sys> to reflect where did you put the
files. Note that if you have some primitive unzipper (like
-pkunzip), you may get a lot of warnings/errors during
+C<pkunzip>), you may get a lot of warnings/errors during
unzipping. Upgrade to C<(w)unzip>.
Below is the sample of what to do to reproduce the configuration on my
-machine:
+machine. In F<VIEW.EXE> you can press C<Ctrl-Insert> now, and
+cut-and-paste from the resulting file - created in the directory you
+started F<VIEW.EXE> from.
+
+For each component, we mention environment variables related to each
+installation directory. Either choose directories to match your
+values of the variables, or create/append-to variables to take into
+account the directories.
=over 3
unzip perl_mlb.zip -d f:/perllib/lib
-If this directory is preserved, you do not need to change
-anything. However, for perl to find it if it is changed, you need to
+If this directory is exactly the same as the prefix which was compiled
+into F<perl.exe>, you do not need to change
+anything. However, for perl to find the library if you use a different
+path, you need to
C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
=item Additional Perl modules
- unzip perl_ste.zip -d f:/perllib/lib/site_perl
+ unzip perl_ste.zip -d f:/perllib/lib/site_perl/5.8.3/
-If you do not change this directory, do nothing. Otherwise put this
+Same remark as above applies. Additionally, if this directory is not
+one of directories on @INC (and @INC is influenced by C<PERLLIB_PREFIX>), you
+need to put this
directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
variable. Do not use C<PERL5LIB> unless you have it set already. See
-L<perl/"ENVIRONMENT">.
+L<perl/"ENVIRONMENT">.
+
+B<[Check whether this extraction directory is still applicable with
+the new directory structure layout!]>
=item Tools to compile Perl modules
unzip perl_blb.zip -d f:/perllib/lib
-If this directory is preserved, you do not need to change
-anything. However, for perl to find it if it is changed, you need to
-C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
+Same remark as for F<perl_ste.zip>.
=item Manpages for Perl and utilities
unzip perl_man.zip -d f:/perllib/man
This directory should better be on C<MANPATH>. You need to have a
-working man to access these files.
+working F<man> to access these files.
=item Manpages for Perl modules
unzip perl_pod.zip -d f:/perllib/lib
-This is used by
by C<perldoc> program (see L<perldoc>), and may be used to
+This is used by
the C<perldoc> program (see L<perldoc>), and may be used to
generate HTML documentation usable by WWW browsers, and
documentation in zillions of other formats: C<info>, C<LaTeX>,
-C<Acrobat>, C<FrameMaker> and so on.
+C<Acrobat>, C<FrameMaker> and so on. [Use programs such as
+F<pod2latex> etc.]
=item Perl manual in F<.INF> format
Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
the above location.
-B<Note.> It may be possible to use some other sh-compatible shell
-(I<not tested>).
+B<Note.> It may be possible to use some other sh-compatible shell (untested).
=back
The automatic and manual perl installation leave precompiled paths
inside perl executables. While these paths are overwriteable (see
-L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
+L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), some people may prefer
binary editing of paths inside the executables/DLLs.
=head1 Accessing documentation
=head2 Manpages
-If you have man installed on your system, and you installed perl
+If you have F<man> installed on your system, and you installed perl
manpages, use something like this:
man perlfunc
set MANPATH=c:/man;f:/perllib/man
+for Perl manpages in C<f:/perllib/man/man1/> etc.
+
=head2 HTML
If you have some WWW browser available, installed the Perl
=head2 GNU C<info> files
Users of Emacs would appreciate it very much, especially with
-C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
-or, alternately, prebuilt info pages.
+C<CPerl> mode loaded. You need to get latest C<pod2texi> from C<CPAN>,
+or, alternately, the prebuilt info pages.
-=head2 F<.PDF> files
+=head2 F<PDF> files
-for C<Acrobat> are available on CPAN (for slightly old version of
+for C<Acrobat> are available on CPAN (may be for slightly older version of
perl).
=head2 C<LaTeX> docs
Here we discuss how to build Perl under OS/2. There is an alternative
(but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
+=head2 The short story
+
+Assume that you are a seasoned porter, so are sure that all the necessary
+tools are already present on your system, and you know how to get the Perl
+source distribution. Untar it, change to the extract directory, and
+
+ gnupatch -p0 < os2\diff.configure
+ sh Configure -des -D prefix=f:/perllib
+ make
+ make test
+ make install
+ make aout_test
+ make aout_install
+
+This puts the executables in f:/perllib/bin. Manually move them to the
+C<PATH>, manually move the built F<perl*.dll> to C<LIBPATH> (here for
+Perl DLL F<*> is a not-very-meaningful hex checksum), and run
+
+ make installcmd INSTALLCMDDIR=d:/ir/on/path
+
+Assuming that the C<man>-files were put on an appropriate location,
+this completes the installation of minimal Perl system. (The binary
+distribution contains also a lot of additional modules, and the
+documentation in INF format.)
+
+What follows is a detailed guide through these steps.
+
=head2 Prerequisites
You need to have the latest EMX development environment, the full
). You need the latest version of F<pdksh> installed as F<sh.exe>.
-Possible locations to get this from are
+Check that you have B<BSD> libraries and headers installed, and -
+optionally - Berkeley DB headers and libraries, and crypt.
+
+Possible locations to get the files:
ftp://hobbes.nmsu.edu/os2/unix/
ftp://ftp.cdrom.com/pub/os2/unix/
ftp://ftp.cdrom.com/pub/os2/dev32/
ftp://ftp.cdrom.com/pub/os2/emx09c/
+It is reported that the following archives contain enough utils to
+build perl: F<gnufutil.zip>, F<gnusutil.zip>, F<gnututil.zip>, F<gnused.zip>,
+F<gnupatch.zip>, F<gnuawk.zip>, F<gnumake.zip>, F<gnugrep.zip>, F<bsddev.zip> and
+F<ksh527rt.zip> (or a later version). Note that all these utilities are
+known to be available from LEO:
-Make sure that no copies or perl are currently running. Later steps
-of the build may fail since an older version of perl.dll loaded into
-memory may be found.
+ ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu
+
+Note also that the F<db.lib> and F<db.a> from the EMX distribution
+are not suitable for multi-threaded compile (even single-threaded
+flavor of Perl uses multi-threaded C RTL, for
+compatibility with XFree86-OS/2). Get a corrected one from
+
+ http://www.ilyaz.org/software/os2/db_mt.zip
+
+If you have I<exactly the same version of Perl> installed already,
+make sure that no copies or perl are currently running. Later steps
+of the build may fail since an older version of F<perl.dll> loaded into
+memory may be found. Running C<make test> becomes meaningless, since
+the test are checking a previous build of perl (this situation is detected
+and reported by F<lib/os2_base.t> test). Do not forget to unset
+C<PERL_EMXLOAD_SEC> in environment.
Also make sure that you have F</tmp> directory on the current drive,
and F<.> directory in your C<LIBPATH>. One may try to correct the
latter condition by
- set BEGINLIBPATH .
+ set BEGINLIBPATH .\.
-if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
+if you use something like F<CMD.EXE> or latest versions of
+F<4os2.exe>. (Setting BEGINLIBPATH to just C<.> is ignored by the
+OS/2 kernel.)
Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
script in F</emx/lib> directory.
shows you do not have it, do I<Selective install>, and choose C<Link
object modules> in I<Optional system utilities/More>. If you get into
-link386, press C<Ctrl-C>.
+link386 prompts, press C<Ctrl-C> to exit.
=head2 Getting perl source
You need to fetch the latest perl source (including developers
releases). With some probability it is located in
- http://www.perl.com/CPAN/src/5.0
- http://www.perl.com/CPAN/src/5.0/unsupported
+ http://www.cpan.org/src/5.0
+ http://www.cpan.org/src/5.0/unsupported
If not, you may need to dig in the indices to find it in the directory
of the current maintainer.
Quick cycle of developers release may break the OS/2 build time to
time, looking into
- http://www.perl.com/CPAN/ports/os2/ilyaz/
+ http://www.cpan.org/ports/os2/
may indicate the latest release which was publicly released by the
maintainer. Note that the release may include some additional patches
=head2 Application of the patches
-You need to apply the patches in F<./os2/diff.*> and
-F<./os2/POSIX.mkfifo> like this:
+You need to apply the patches in F<./os2/diff.*> like this:
- gnupatch -p0 < os2\POSIX.mkfifo
gnupatch -p0 < os2\diff.configure
You may also need to apply the patches supplied with the binary
-distribution of perl.
-
-Note also that the F<db.lib> and F<db.a> from the EMX distribution
-are not suitable for multi-threaded compile (note that currently perl
-is not multithread-safe, but is compiled as multithreaded for
-compatibility with XFree86-OS/2). Get a corrected one from
-
- ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
+distribution of perl. It also makes sense to look on the
+perl5-porters mailing list for the latest OS/2-related patches (see
+L<http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/>). Such
+patches usually contain strings C</os2/> and C<patch>, so it makes
+sense looking for these strings.
=head2 Hand-editing
see L<"PERLLIB_PREFIX">.
I<Ignore the message about missing C<ln>, and about C<-c> option to
-tr>. In fact if you can trace where the latter spurious warning
-comes from, please inform me.
+tr>. The latter is most probably already fixed, if you see it and can trace
+where the latter spurious warning comes from, please inform me.
Now
make
At some moment the built may die, reporting a I<version mismatch> or
-I<unable to run F<perl>>. This means that most of the build has been
-finished, and it is the time to move the constructed F<perl.dll> to
-some I<absolute> location in LIBPATH. After this is done the build
-should finish without a lot of fuss. I<One can avoid the interruption
-if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
-probably this is not needed anymore, since F<miniperl.exe> is linked
-statically now.>
-
-Warnings which are safe to ignore: I<mkfifo() redefined> inside
-F<POSIX.c>.
+I<unable to run F<perl>>. This means that you do not have F<.> in
+your LIBPATH, so F<perl.exe> cannot find the needed F<perl67B2.dll> (treat
+these hex digits as line noise). After this is fixed the build
+should finish without a lot of fuss.
=head2 Testing
make test
-Some tests (4..6) should fail. Some perl invocations should end in a
-segfault (system error C<SYS3175>). To get finer error reports,
+All tests should succeed (with some of them skipped). If you have the
+same version of Perl installed, it is crucial that you have C<.> early
+in your LIBPATH (or in BEGINLIBPATH), otherwise your tests will most
+probably test the wrong version of Perl.
+
+Some tests may generate extra messages similar to
- cd t
- perl harness
+=over 4
-The report you get may look like
+=item A lot of C<bad free>
- Failed Test Status Wstat Total Fail Failed List of failed
- ---------------------------------------------------------------
- io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
- lib/io_pipe.t 3 768 6 ?? % ??
- lib/io_sock.t 3 768 5 ?? % ??
- op/stat.t 56 5 8.93% 3-4, 20, 35, 39
- Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
+in database tests related to Berkeley DB. I<This should be fixed already.>
+If it persists, you may disable this warnings, see L<"PERL_BADFREE">.
+
+=item Process terminated by SIGTERM/SIGINT
+
+This is a standard message issued by OS/2 applications. *nix
+applications die in silence. It is considered to be a feature. One can
+easily disable this by appropriate sighandlers.
-Note that using `make test' target two more tests may fail: C<op/exec:1>
-because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
-that the buffers are not flushed on C<_exit> (this is a bug in the test
-which assumes that tty output is buffered).
+However the test engine bleeds these message to screen in unexpected
+moments. Two messages of this kind I<should> be present during
+testing.
-I submitted a patch to EMX which makes it possible to fork() with EMX
-dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
-that soon the number of failing tests may decrease yet more.
+=back
-However, the test F<lib/io_udp.t> is disabled, since it never terminates, I
-do not know why. Comments/fixes welcome.
+To get finer test reports, call
-The reasons for failed tests are:
+ perl t/harness
-=over 8
+The report with F<io/pipe.t> failing may look like this:
-=item F<io/fs.t>
+ Failed Test Status Wstat Total Fail Failed List of failed
+ ------------------------------------------------------------
+ io/pipe.t 12 1 8.33% 9
+ 7 tests skipped, plus 56 subtests skipped.
+ Failed 1/195 test scripts, 99.49% okay. 1/6542 subtests failed, 99.98% okay.
-Checks I<file system> operations. Tests:
+The reasons for most important skipped tests are:
-=over 10
+=over 8
-=item 2-5, 7-11
+=item F<op/fs.t>
-Check C<link()> and C<inode count> - nonesuch under OS/2.
+=over 4
=item 18
-Checks C<atime> and C<mtime> of C<stat()> - I could not understand this test.
+Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS
+provides only 2sec time granularity (for compatibility with FAT?).
=item 25
=back
-=item F<lib/io_pipe.t>
-
-Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
-dynamic extension loaded - unsupported now.
-
-=item F<lib/io_sock.t>
-
-Checks C<IO::Socket> module. Some feature of EMX - test fork()s
-with dynamic extension loaded - unsupported now.
-
=item F<op/stat.t>
Checks C<stat()>. Tests:
=over 4
-=item 3
-
-Checks C<inode count> - nonesuch under OS/2.
-
=item 4
-Checks C<mtime> and C<ctime> of C<stat()> - I could not understand this test.
-
-=item 20
-
-Checks C<-x> - determined by the file extension only under OS/2.
-
-=item 35
-
-Needs F</usr/bin>.
-
-=item 39
-
-Checks C<-t> of F</dev/null>. Should not fail!
+Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS
+provides only 2sec time granularity (for compatibility with FAT?).
=back
=back
-In addition to errors, you should get a lot of warnings.
-
-=over 4
-
-=item A lot of `bad free'
-
-in databases related to Berkeley DB. This is a confirmed bug of
-DB. You may disable this warnings, see L<"PERL_BADFREE">.
-
-=item Process terminated by SIGTERM/SIGINT
-
-This is a standard message issued by OS/2 applications. *nix
-applications die in silence. It is considered a feature. One can
-easily disable this by appropriate sighandlers.
-
-However the test engine bleeds these message to screen in unexpected
-moments. Two messages of this kind I<should> be present during
-testing.
-
-=item F<*/sh.exe>: ln: not found
-
-=item C<ls>: /dev: No such file or directory
-
-The last two should be self-explanatory. The test suite discovers that
-the system it runs on is not I<that much> *nixish.
-
-=back
-
-A lot of `bad free'... in databases, bug in DB confirmed on other
-platforms. You may disable it by setting PERL_BADFREE environment variable
-to 1.
-
=head2 Installing the built perl
+If you haven't yet moved C<perl*.dll> onto LIBPATH, do it now.
+
Run
make install
Run
- make cmdscripts INSTALLCMDDIR=d:/ir/on/path
+ make installcmd INSTALLCMDDIR=d:/ir/on/path
to convert perl utilities to F<.cmd> files and put them on
PATH. You need to put F<.EXE>-utilities on path manually. They are
installed in C<$prefix/bin>, here C<$prefix> is what you gave to
F<Configure>, see L<Making>.
+If you use C<man>, either move the installed F<*/man/> directories to
+your C<MANPATH>, or modify C<MANPATH> to match the location. (One
+could have avoided this by providing a correct C<manpath> option to
+F<./Configure>, or editing F<./config.sh> between configuring and
+making steps.)
+
=head2 C<a.out>-style build
Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
Manually put F<perl_.exe> to a location on your PATH.
-Since C<perl_> has the extensions prebuilt, it does not suffer from
-the I<dynamic extensions + fork()> syndrome, thus the failing tests
-look like
-
- Failed Test Status Wstat Total Fail Failed List of failed
- ---------------------------------------------------------------
- io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
- op/stat.t 56 5 8.93% 3-4, 20, 35, 39
- Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
-
B<Note.> The build process for C<perl_> I<does not know> about all the
dependencies, so you should make sure that anything is up-to-date,
say, by doing
- make perl.dll
+ make perl_dll
first.
+=head1 Building a binary distribution
+
+[This section provides a short overview only...]
+
+Building should proceed differently depending on whether the version of perl
+you install is already present and used on your system, or is a new version
+not yet used. The description below assumes that the version is new, so
+installing its DLLs and F<.pm> files will not disrupt the operation of your
+system even if some intermediate steps are not yet fully working.
+
+The other cases require a little bit more convoluted procedures. Below I
+suppose that the current version of Perl is C<5.8.2>, so the executables are
+named accordingly.
+
+=over
+
+=item 1.
+
+Fully build and test the Perl distribution. Make sure that no tests are
+failing with C<test> and C<aout_test> targets; fix the bugs in Perl and
+the Perl test suite detected by these tests. Make sure that C<all_test>
+make target runs as clean as possible. Check that C<os2/perlrexx.cmd>
+runs fine.
+
+=item 2.
+
+Fully install Perl, including C<installcmd> target. Copy the generated DLLs
+to C<LIBPATH>; copy the numbered Perl executables (as in F<perl5.8.2.exe>)
+to C<PATH>; copy C<perl_.exe> to C<PATH> as C<perl_5.8.2.exe>. Think whether
+you need backward-compatibility DLLs. In most cases you do not need to install
+them yet; but sometime this may simplify the following steps.
+
+=item 3.
+
+Make sure that C<CPAN.pm> can download files from CPAN. If not, you may need
+to manually install C<Net::FTP>.
+
+=item 4.
+
+Install the bundle C<Bundle::OS2_default>
+
+ perl5.8.2 -MCPAN -e "install Bundle::OS2_default" < nul |& tee 00cpan_i_1
+
+This may take a couple of hours on 1GHz processor (when run the first time).
+And this should not be necessarily a smooth procedure. Some modules may not
+specify required dependencies, so one may need to repeat this procedure several
+times until the results stabilize.
+
+ perl5.8.2 -MCPAN -e "install Bundle::OS2_default" < nul |& tee 00cpan_i_2
+ perl5.8.2 -MCPAN -e "install Bundle::OS2_default" < nul |& tee 00cpan_i_3
+
+Even after they stabilize, some tests may fail.
+
+Fix as many discovered bugs as possible. Document all the bugs which are not
+fixed, and all the failures with unknown reasons. Inspect the produced logs
+F<00cpan_i_1> to find suspiciously skipped tests, and other fishy events.
+
+Keep in mind that I<installation> of some modules may fail too: for example,
+the DLLs to update may be already loaded by F<CPAN.pm>. Inspect the C<install>
+logs (in the example above F<00cpan_i_1> etc) for errors, and install things
+manually, as in
+
+ cd $CPANHOME/.cpan/build/Digest-MD5-2.31
+ make install
+
+Some distributions may fail some tests, but you may want to install them
+anyway (as above, or via C<force install> command of C<CPAN.pm> shell-mode).
+
+Since this procedure may take quite a long time to complete, it makes sense
+to "freeze" your CPAN configuration by disabling periodic updates of the
+local copy of CPAN index: set C<index_expire> to some big value (I use 365),
+then save the settings
+
+ CPAN> o conf index_expire 365
+ CPAN> o conf commit
+
+Reset back to the default value C<1> when you are finished.
+
+=item 5.
+
+When satisfied with the results, rerun the C<installcmd> target. Now you
+can copy C<perl5.8.2.exe> to C<perl.exe>, and install the other OMF-build
+executables: C<perl__.exe> etc. They are ready to be used.
+
+=item 6.
+
+Change to the C<./pod> directory of the build tree, download the Perl logo
+F<CamelGrayBig.BMP>, and run
+
+ ( perl2ipf > perl.ipf ) |& tee 00ipf
+ ipfc /INF perl.ipf |& tee 00inf
+
+This produces the Perl docs online book C<perl.INF>. Install in on
+C<BOOKSHELF> path.
+
+=item 7.
+
+Now is the time to build statically linked executable F<perl_.exe> which
+includes newly-installed via C<Bundle::OS2_default> modules. Doing testing
+via C<CPAN.pm> is going to be painfully slow, since it statically links
+a new executable per XS extension.
+
+Here is a possible workaround: create a toplevel F<Makefile.PL> in
+F<$CPANHOME/.cpan/build/> with contents being (compare with L<Making
+executables with a custom collection of statically loaded extensions>)
+
+ use ExtUtils::MakeMaker;
+ WriteMakefile NAME => 'dummy';
+
+execute this as
+
+ perl_5.8.2.exe Makefile.PL <nul |& tee 00aout_c1
+ make -k all test <nul |& 00aout_t1
+
+Again, this procedure should not be absolutely smooth. Some C<Makefile.PL>'s
+in subdirectories may be buggy, and would not run as "child" scripts. The
+interdependency of modules can strike you; however, since non-XS modules
+are already installed, the prerequisites of most modules have a very good
+chance to be present.
+
+If you discover some glitches, move directories of problematic modules to a
+different location; if these modules are non-XS modules, you may just ignore
+them - they are already installed; the remaining, XS, modules you need to
+install manually one by one.
+
+After each such removal you need to rerun the C<Makefile.PL>/C<make> process;
+usually this procedure converges soon. (But be sure to convert all the
+necessary external C libraries from F<.lib> format to F<.a> format: run one of
+
+ emxaout foo.lib
+ emximp -o foo.a foo.lib
+
+whichever is appropriate.) Also, make sure that the DLLs for external
+libraries are usable with with executables compiled without C<-Zmtd> options.
+
+When you are sure that only a few subdirectories
+lead to failures, you may want to add C<-j4> option to C<make> to speed up
+skipping subdirectories with already finished build.
+
+When you are satisfied with the results of tests, install the build C libraries
+for extensions:
+
+ make install |& tee 00aout_i
+
+Now you can rename the file F<./perl.exe> generated during the last phase
+to F<perl_5.8.2.exe>; place it on C<PATH>; if there is an inter-dependency
+between some XS modules, you may need to repeat the C<test>/C<install> loop
+with this new executable and some excluded modules - until the procedure
+converges.
+
+Now you have all the necessary F<.a> libraries for these Perl modules in the
+places where Perl builder can find it. Use the perl builder: change to an
+empty directory, create a "dummy" F<Makefile.PL> again, and run
+
+ perl_5.8.2.exe Makefile.PL |& tee 00c
+ make perl |& tee 00p
+
+This should create an executable F<./perl.exe> with all the statically loaded
+extensions built in. Compare the generated F<perlmain.c> files to make sure
+that during the iterations the number of loaded extensions only increases.
+Rename F<./perl.exe> to F<perl_5.8.2.exe> on C<PATH>.
+
+When it converges, you got a functional variant of F<perl_5.8.2.exe>; copy it
+to C<perl_.exe>. You are done with generation of the local Perl installation.
+
+=item 8.
+
+Make sure that the installed modules are actually installed in the location
+of the new Perl, and are not inherited from entries of @INC given for
+inheritance from the older versions of Perl: set C<PERLLIB_582_PREFIX> to
+redirect the new version of Perl to a new location, and copy the installed
+files to this new location. Redo the tests to make sure that the versions of
+modules inherited from older versions of Perl are not needed.
+
+Actually, the log output of L<pod2ipf> during the step 6 gives a very detailed
+info about which modules are loaded from which place; so you may use it as
+an additional verification tool.
+
+Check that some temporary files did not make into the perl install tree.
+Run something like this
+
+ pfind . -f "!(/\.(pm|pl|ix|al|h|a|lib|txt|pod|imp|bs|dll|ld|bs|inc|xbm|yml|cgi|uu|e2x|skip|packlist|eg|cfg|html|pub|enc|all|ini|po|pot)$/i or /^\w+$/") | less
+
+in the install tree (both top one and F<sitelib> one).
+
+Compress all the DLLs with F<lxlite>. The tiny F<.exe> can be compressed with
+C</c:max> (the bug only appears when there is a fixup in the last 6 bytes of a
+page (?); since the tiny executables are much smaller than a page, the bug
+will not hit). Do not compress C<perl_.exe> - it would not work under DOS.
+
+=item 9.
+
+Now you can generate the binary distribution. This is done by running the
+test of the CPAN distribution C<OS2::SoftInstaller>. Tune up the file
+F<test.pl> to suit the layout of current version of Perl first. Do not
+forget to pack the necessary external DLLs accordingly. Include the
+description of the bugs and test suite failures you could not fix. Include
+the small-stack versions of Perl executables from Perl build directory.
+
+Include F<perl5.def> so that people can relink the perl DLL preserving
+the binary compatibility, or can create compatibility DLLs. Include the diff
+files (C<diff -pu old new>) of fixes you did so that people can rebuild your
+version. Include F<perl5.map> so that one can use remote debugging.
+
+=item 10.
+
+Share what you did with the other people. Relax. Enjoy fruits of your work.
+
+=item 11.
+
+Brace yourself for thanks, bug reports, hate mail and spam coming as result
+of the previous step. No good deed should remain unpunished!
+
+=back
+
+=head1 Building custom F<.EXE> files
+
+The Perl executables can be easily rebuilt at any moment. Moreover, one can
+use the I<embedding> interface (see L<perlembed>) to make very customized
+executables.
+
+=head2 Making executables with a custom collection of statically loaded extensions
+
+It is a little bit easier to do so while I<decreasing> the list of statically
+loaded extensions. We discuss this case only here.
+
+=over
+
+=item 1.
+
+Change to an empty directory, and create a placeholder <Makefile.PL>:
+
+ use ExtUtils::MakeMaker;
+ WriteMakefile NAME => 'dummy';
+
+=item 2.
+
+Run it with the flavor of Perl (F<perl.exe> or F<perl_.exe>) you want to
+rebuild.
+
+ perl_ Makefile.PL
+
+=item 3.
+
+Ask it to create new Perl executable:
+
+ make perl
+
+(you may need to manually add C<PERLTYPE=-DPERL_CORE> to this commandline on
+some versions of Perl; the symptom is that the command-line globbing does not
+work from OS/2 shells with the newly-compiled executable; check with
+
+ .\perl.exe -wle "print for @ARGV" *
+
+).
+
+=item 4.
+
+The previous step created F<perlmain.c> which contains a list of newXS() calls
+near the end. Removing unnecessary calls, and rerunning
+
+ make perl
+
+will produce a customized executable.
+
+=back
+
+=head2 Making executables with a custom search-paths
+
+The default perl executable is flexible enough to support most usages.
+However, one may want something yet more flexible; for example, one may want
+to find Perl DLL relatively to the location of the EXE file; or one may want
+to ignore the environment when setting the Perl-library search patch, etc.
+
+If you fill comfortable with I<embedding> interface (see L<perlembed>), such
+things are easy to do repeating the steps outlined in L<Making
+executables with a custom collection of statically loaded extensions>, and
+doing more comprehensive edits to main() of F<perlmain.c>. The people with
+little desire to understand Perl can just rename main(), and do necessary
+modification in a custom main() which calls the renamed function in appropriate
+time.
+
+However, there is a third way: perl DLL exports the main() function and several
+callbacks to customize the search path. Below is a complete example of a
+"Perl loader" which
+
+=over
+
+=item 1.
+
+Looks for Perl DLL in the directory C<$exedir/../dll>;
+
+=item 2.
+
+Prepends the above directory to C<BEGINLIBPATH>;
+
+=item 3.
+
+Fails if the Perl DLL found via C<BEGINLIBPATH> is different from what was
+loaded on step 1; e.g., another process could have loaded it from C<LIBPATH>
+or from a different value of C<BEGINLIBPATH>. In these cases one needs to
+modify the setting of the system so that this other process either does not
+run, or loads the DLL from C<BEGINLIBPATH> with C<LIBPATHSTRICT=T> (available
+with kernels after September 2000).
+
+=item 4.
+
+Loads Perl library from C<$exedir/../dll/lib/>.
+
+=item 5.
+
+Uses Bourne shell from C<$exedir/../dll/sh/ksh.exe>.
+
+=back
+
+For best results compile the C file below with the same options as the Perl
+DLL. However, a lot of functionality will work even if the executable is not
+an EMX applications, e.g., if compiled with
+
+ gcc -Wall -DDOSISH -DOS2=1 -O2 -s -Zomf -Zsys perl-starter.c -DPERL_DLL_BASENAME=\"perl312F\" -Zstack 8192 -Zlinker /PM:VIO
+
+Here is the sample C file:
+
+ #define INCL_DOS
+ #define INCL_NOPM
+ /* These are needed for compile if os2.h includes os2tk.h, not os2emx.h */
+ #define INCL_DOSPROCESS
+ #include <os2.h>
+
+ #include "EXTERN.h"
+ #define PERL_IN_MINIPERLMAIN_C
+ #include "perl.h"
+
+ static char *me;
+ HMODULE handle;
+
+ static void
+ die_with(char *msg1, char *msg2, char *msg3, char *msg4)
+ {
+ ULONG c;
+ char *s = " error: ";
+
+ DosWrite(2, me, strlen(me), &c);
+ DosWrite(2, s, strlen(s), &c);
+ DosWrite(2, msg1, strlen(msg1), &c);
+ DosWrite(2, msg2, strlen(msg2), &c);
+ DosWrite(2, msg3, strlen(msg3), &c);
+ DosWrite(2, msg4, strlen(msg4), &c);
+ DosWrite(2, "\r\n", 2, &c);
+ exit(255);
+ }
+
+ typedef ULONG (*fill_extLibpath_t)(int type, char *pre, char *post, int replace, char *msg);
+ typedef int (*main_t)(int type, char *argv[], char *env[]);
+ typedef int (*handler_t)(void* data, int which);
+
+ #ifndef PERL_DLL_BASENAME
+ # define PERL_DLL_BASENAME "perl"
+ #endif
+
+ static HMODULE
+ load_perl_dll(char *basename)
+ {
+ char buf[300], fail[260];
+ STRLEN l, dirl;
+ fill_extLibpath_t f;
+ ULONG rc_fullname;
+ HMODULE handle, handle1;
+
+ if (_execname(buf, sizeof(buf) - 13) != 0)
+ die_with("Can't find full path: ", strerror(errno), "", "");
+ /* XXXX Fill `me' with new value */
+ l = strlen(buf);
+ while (l && buf[l-1] != '/' && buf[l-1] != '\\')
+ l--;
+ dirl = l - 1;
+ strcpy(buf + l, basename);
+ l += strlen(basename);
+ strcpy(buf + l, ".dll");
+ if ( (rc_fullname = DosLoadModule(fail, sizeof fail, buf, &handle)) != 0
+ && DosLoadModule(fail, sizeof fail, basename, &handle) != 0 )
+ die_with("Can't load DLL ", buf, "", "");
+ if (rc_fullname)
+ return handle; /* was loaded with short name; all is fine */
+ if (DosQueryProcAddr(handle, 0, "fill_extLibpath", (PFN*)&f))
+ die_with(buf, ": DLL exports no symbol ", "fill_extLibpath", "");
+ buf[dirl] = 0;
+ if (f(0 /*BEGINLIBPATH*/, buf /* prepend */, NULL /* append */,
+ 0 /* keep old value */, me))
+ die_with(me, ": prepending BEGINLIBPATH", "", "");
+ if (DosLoadModule(fail, sizeof fail, basename, &handle1) != 0)
+ die_with(me, ": finding perl DLL again via BEGINLIBPATH", "", "");
+ buf[dirl] = '\\';
+ if (handle1 != handle) {
+ if (DosQueryModuleName(handle1, sizeof(fail), fail))
+ strcpy(fail, "???");
+ die_with(buf, ":\n\tperl DLL via BEGINLIBPATH is different: \n\t",
+ fail,
+ "\n\tYou may need to manipulate global BEGINLIBPATH and LIBPATHSTRICT"
+ "\n\tso that the other copy is loaded via BEGINLIBPATH.");
+ }
+ return handle;
+ }
+
+ int
+ main(int argc, char **argv, char **env)
+ {
+ main_t f;
+ handler_t h;
+
+ me = argv[0];
+ /**/
+ handle = load_perl_dll(PERL_DLL_BASENAME);
+
+ if (DosQueryProcAddr(handle, 0, "Perl_OS2_handler_install", (PFN*)&h))
+ die_with(PERL_DLL_BASENAME, ": DLL exports no symbol ", "Perl_OS2_handler_install", "");
+ if ( !h((void *)"~installprefix", Perlos2_handler_perllib_from)
+ || !h((void *)"~dll", Perlos2_handler_perllib_to)
+ || !h((void *)"~dll/sh/ksh.exe", Perlos2_handler_perl_sh) )
+ die_with(PERL_DLL_BASENAME, ": Can't install @INC manglers", "", "");
+
+ if (DosQueryProcAddr(handle, 0, "dll_perlmain", (PFN*)&f))
+ die_with(PERL_DLL_BASENAME, ": DLL exports no symbol ", "dll_perlmain", "");
+ return f(argc, argv, env);
+ }
+
+
=head1 Build FAQ
=head2 Some C</> became C<\> in pdksh.
You do not have MT-safe F<db.lib>. See L<Prerequisites>.
-=head2 Problems with tr
+=head2 Problems with tr or sed
-reported with very old version of tr.
+reported with very old version of tr and sed.
=head2 Some problem (forget which ;-)
You use an old version of GNU make. See L<Prerequisites>.
+=head2 op/sprintf test failure
+
+This can result from a bug in emx sprintf which was fixed in 0.9d fix 03.
+
=head1 Specific (mis)features of OS/2 port
=head2 C<setpriority>, C<getpriority>
ports of '94 - 95. The priorities are absolute, go from 32 to -95,
lower is quicker. 0 is the default priority.
+B<WARNING>. Calling C<getpriority> on a non-existing process could lock
+the system before Warp3 fixpak22. Starting with Warp3, Perl will use
+a workaround: it aborts getpriority() if the process is not present.
+This is not possible on older versions C<2.*>, and has a race
+condition anyway.
+
=head2 C<system()>
Multi-argument form of C<system()> allows an additional numeric
argument. The meaning of this argument is described in
L<OS2::Process>.
+When finding a program to run, Perl first asks the OS to look for executables
+on C<PATH> (OS/2 adds extension F<.exe> if no extension is present).
+If not found, it looks for a script with possible extensions
+added in this order: no extension, F<.cmd>, F<.btm>,
+F<.bat>, F<.pl>. If found, Perl checks the start of the file for magic
+strings C<"#!"> and C<"extproc ">. If found, Perl uses the rest of the
+first line as the beginning of the command line to run this script. The
+only mangling done to the first line is extraction of arguments (currently
+up to 3), and ignoring of the path-part of the "interpreter" name if it can't
+be found using the full path.
+
+E.g., C<system 'foo', 'bar', 'baz'> may lead Perl to finding
+F<C:/emx/bin/foo.cmd> with the first line being
+
+ extproc /bin/bash -x -c
+
+If F</bin/bash.exe> is not found, then Perl looks for an executable F<bash.exe> on
+C<PATH>. If found in F<C:/emx.add/bin/bash.exe>, then the above system() is
+translated to
+
+ system qw(C:/emx.add/bin/bash.exe -x -c C:/emx/bin/foo.cmd bar baz)
+
+One additional translation is performed: instead of F</bin/sh> Perl uses
+the hardwired-or-customized shell (see C<L<"PERL_SH_DIR">>).
+
+The above search for "interpreter" is recursive: if F<bash> executable is not
+found, but F<bash.btm> is found, Perl will investigate its first line etc.
+The only hardwired limit on the recursion depth is implicit: there is a limit
+4 on the number of additional arguments inserted before the actual arguments
+given to system(). In particular, if no additional arguments are specified
+on the "magic" first lines, then the limit on the depth is 4.
+
+If Perl finds that the found executable is of PM type when the
+current session is not, it will start the new process in a separate session of
+necessary type. Call via C<OS2::Process> to disable this magic.
+
+B<WARNING>. Due to the described logic, you need to explicitly
+specify F<.com> extension if needed. Moreover, if the executable
+F<perl5.6.1> is requested, Perl will not look for F<perl5.6.1.exe>.
+[This may change in the future.]
+
=head2 C<extproc> on the first line
-If the first chars of a script are C<"extproc ">, this line is treated
+If the first chars of a Perl script are C<"extproc ">, this line is treated
as C<#!>-line, thus all the switches on this line are processed (twice
-if script was started via cmd.exe).
+if script was started via cmd.exe). See L<perlrun/DESCRIPTION>.
=head2 Additional modules:
-L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. This
-modules provide access to additional numeric argument for C<system>,
-to DLLs having functions with REXX signature and to REXX runtime, to
+L<OS2::Process>, L<OS2::DLL>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. These
+modules provide access to additional numeric argument for C<system>
+and to the information about the running process,
+to DLLs having functions with REXX signature and to the REXX runtime, to
OS/2 databases in the F<.INI> format, and to Extended Attributes.
Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
-C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
+C<OS2::FTP>, are included into C<ILYAZ> directory, mirrored on CPAN.
+Other OS/2-related extensions are available too.
=head2 Prebuilt methods:
=item C<Cwd::change_drive(name)>
+chanes the "current" drive.
=item C<Cwd::sys_is_absolute(name)>
file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
current dir.
-=item C<Cwd::extLibpath([type])
+=item C<Cwd::extLibpath([type])>
Get current value of extended library search path. If C<type> is
-present and I<true>, works with END_LIBPATH, otherwise with
-C<BEGIN_LIBPATH>.
+present and positive, works with C<END_LIBPATH>, if negative, works
+with C<LIBPATHSTRICT>, otherwise with C<BEGIN_LIBPATH>.
=item C<Cwd::extLibpath_set( path [, type ] )>
Set current value of extended library search path. If C<type> is
-present and I<true>, works with END_LIBPATH, otherwise with
-C<BEGIN_LIBPATH>.
+present and positive, works with <END_LIBPATH>, if negative, works
+with C<LIBPATHSTRICT>, otherwise with C<BEGIN_LIBPATH>.
+
+=item C<OS2::Error(do_harderror,do_exception)>
+
+Returns C<undef> if it was not called yet, otherwise bit 1 is
+set if on the previous call do_harderror was enabled, bit
+2 is set if on previous call do_exception was enabled.
+
+This function enables/disables error popups associated with
+hardware errors (Disk not ready etc.) and software exceptions.
+
+I know of no way to find out the state of popups I<before> the first call
+to this function.
+
+=item C<OS2::Errors2Drive(drive)>
+
+Returns C<undef> if it was not called yet, otherwise return false if errors
+were not requested to be written to a hard drive, or the drive letter if
+this was requested.
+
+This function may redirect error popups associated with hardware errors
+(Disk not ready etc.) and software exceptions to the file POPUPLOG.OS2 at
+the root directory of the specified drive. Overrides OS2::Error() specified
+by individual programs. Given argument undef will disable redirection.
+
+Has global effect, persists after the application exits.
+
+I know of no way to find out the state of redirection of popups to the disk
+I<before> the first call to this function.
+
+=item OS2::SysInfo()
+
+Returns a hash with system information. The keys of the hash are
+
+ MAX_PATH_LENGTH, MAX_TEXT_SESSIONS, MAX_PM_SESSIONS,
+ MAX_VDM_SESSIONS, BOOT_DRIVE, DYN_PRI_VARIATION,
+ MAX_WAIT, MIN_SLICE, MAX_SLICE, PAGE_SIZE,
+ VERSION_MAJOR, VERSION_MINOR, VERSION_REVISION,
+ MS_COUNT, TIME_LOW, TIME_HIGH, TOTPHYSMEM, TOTRESMEM,
+ TOTAVAILMEM, MAXPRMEM, MAXSHMEM, TIMER_INTERVAL,
+ MAX_COMP_LENGTH, FOREGROUND_FS_SESSION,
+ FOREGROUND_PROCESS
+
+=item OS2::BootDrive()
+
+Returns a letter without colon.
+
+=item C<OS2::MorphPM(serve)>, C<OS2::UnMorphPM(serve)>
+
+Transforms the current application into a PM application and back.
+The argument true means that a real message loop is going to be served.
+OS2::MorphPM() returns the PM message queue handle as an integer.
+
+See L<"Centralized management of resources"> for additional details.
+
+=item C<OS2::Serve_Messages(force)>
+
+Fake on-demand retrieval of outstanding PM messages. If C<force> is false,
+will not dispatch messages if a real message loop is known to
+be present. Returns number of messages retrieved.
+
+Dies with "QUITing..." if WM_QUIT message is obtained.
+
+=item C<OS2::Process_Messages(force [, cnt])>
+
+Retrieval of PM messages until window creation/destruction.
+If C<force> is false, will not dispatch messages if a real message loop
+is known to be present.
+
+Returns change in number of windows. If C<cnt> is given,
+it is incremented by the number of messages retrieved.
+
+Dies with "QUITing..." if WM_QUIT message is obtained.
+
+=item C<OS2::_control87(new,mask)>
+
+the same as L<_control87(3)> of EMX. Takes integers as arguments, returns
+the previous coprocessor control word as an integer. Only bits in C<new> which
+are present in C<mask> are changed in the control word.
+
+=item OS2::get_control87()
+
+gets the coprocessor control word as an integer.
+
+=item C<OS2::set_control87_em(new=MCW_EM,mask=MCW_EM)>
+
+The variant of OS2::_control87() with default values good for
+handling exception mask: if no C<mask>, uses exception mask part of C<new>
+only. If no C<new>, disables all the floating point exceptions.
+
+See L<"Misfeatures"> for details.
+
+=item C<OS2::DLLname([how [, \&xsub]])>
+
+Gives the information about the Perl DLL or the DLL containing the C
+function bound to by C<&xsub>. The meaning of C<how> is: default (2):
+full name; 0: handle; 1: module name.
=back
eventually).
+=head2 Prebuilt variables:
+
+=over 4
+
+=item $OS2::emx_rev
+
+numeric value is the same as _emx_rev of EMX, a string value the same
+as _emx_vprt (similar to C<0.9c>).
+
+=item $OS2::emx_env
+
+same as _emx_env of EMX, a number similar to 0x8001.
+
+=item $OS2::os_ver
+
+a number C<OS_MAJOR + 0.001 * OS_MINOR>.
+
+=item $OS2::is_aout
+
+true if the Perl library was compiled in AOUT format.
+
+=item $OS2::can_fork
+
+true if the current executable is an AOUT EMX executable, so Perl can
+fork. Do not use this, use the portable check for
+$Config::Config{dfork}.
+
+=item $OS2::nsyserror
+
+This variable (default is 1) controls whether to enforce the contents
+of $^E to start with C<SYS0003>-like id. If set to 0, then the string
+value of $^E is what is available from the OS/2 message file. (Some
+messages in this file have an C<SYS0003>-like id prepended, some not.)
+
+=back
+
=head2 Misfeatures
=over 4
-=item
+=item *
+
+Since L<flock(3)> is present in EMX, but is not functional, it is
+emulated by perl. To disable the emulations, set environment variable
+C<USE_PERL_FLOCK=0>.
-Since L<flock(3)> is present in EMX, but is not functional, the same is
-true for perl. Here is the list of things which may be "broken" on
+=item *
+
+Here is the list of things which may be "broken" on
EMX (from EMX docs):
-=over
+=over 4
=item *
=item *
-L<flock(3)> is not yet implemented (dummy function).
+L<flock(3)> is not yet implemented (dummy function). (Perl has a workaround.)
=item *
Note that C<kill -9> does not work with the current version of EMX.
-=item
+=item *
+
+See L<"Text-mode filehandles">.
+
+=item *
-Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
-of F<sh.exe> plague perl as well.
+Unix-domain sockets on OS/2 live in a pseudo-file-system C</sockets/...>.
+To avoid a failure to create a socket with a name of a different form,
+C<"/socket/"> is prepended to the socket name (unless it starts with this
+already).
-In particular, uppercase letters do not work in C<[...]>-patterns with
-the current pdksh.
+This may lead to problems later in case the socket is accessed via the
+"usual" file-system calls using the "initial" name.
+
+=item *
+
+Apparently, IBM used a compiler (for some period of time around '95?) which
+changes FP mask right and left. This is not I<that> bad for IBM's
+programs, but the same compiler was used for DLLs which are used with
+general-purpose applications. When these DLLs are used, the state of
+floating-point flags in the application is not predictable.
+
+What is much worse, some DLLs change the floating point flags when in
+_DLLInitTerm() (e.g., F<TCP32IP>). This means that even if you do not I<call>
+any function in the DLL, just the act of loading this DLL will reset your
+flags. What is worse, the same compiler was used to compile some HOOK DLLs.
+Given that HOOK dlls are executed in the context of I<all> the applications
+in the system, this means a complete unpredictablity of floating point
+flags on systems using such HOOK DLLs. E.g., F<GAMESRVR.DLL> of B<DIVE>
+origin changes the floating point flags on each write to the TTY of a VIO
+(windowed text-mode) applications.
+
+Some other (not completely debugged) situations when FP flags change include
+some video drivers (?), and some operations related to creation of the windows.
+People who code B<OpenGL> may have more experience on this.
+
+Perl is generally used in the situation when all the floating-point
+exceptions are ignored, as is the default under EMX. If they are not ignored,
+some benign Perl programs would get a C<SIGFPE> and would die a horrible death.
+
+To circumvent this, Perl uses two hacks. They help against I<one> type of
+damage only: FP flags changed when loading a DLL.
+
+One of the hacks is to disable floating point exceptions on Perl startup (as
+is the default with EMX). This helps only with compile-time-linked DLLs
+changing the flags before main() had a chance to be called.
+
+The other hack is to restore FP flags after a call to dlopen(). This helps
+against similar damage done by DLLs _DLLInitTerm() at runtime. Currently
+no way to switch these hacks off is provided.
=back
C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
+=item C<mkdir>, C<rmdir>
+
+these EMX functions do not work if the path contains a trailing C</>.
+Perl contains a workaround for this.
+
+=item C<flock>
+
+Since L<flock(3)> is present in EMX, but is not functional, it is
+emulated by perl. To disable the emulations, set environment variable
+C<USE_PERL_FLOCK=0>.
+
+=back
+
+=head2 Identifying DLLs
+
+All the DLLs built with the current versions of Perl have ID strings
+identifying the name of the extension, its version, and the version
+of Perl required for this DLL. Run C<bldlevel DLL-name> to find this
+info.
+
+=head2 Centralized management of resources
+
+Since to call certain OS/2 API one needs to have a correctly initialized
+C<Win> subsystem, OS/2-specific extensions may require getting C<HAB>s and
+C<HMQ>s. If an extension would do it on its own, another extension could
+fail to initialize.
+
+Perl provides a centralized management of these resources:
+
+=over
+
+=item C<HAB>
+
+To get the HAB, the extension should call C<hab = perl_hab_GET()> in C. After
+this call is performed, C<hab> may be accessed as C<Perl_hab>. There is
+no need to release the HAB after it is used.
+
+If by some reasons F<perl.h> cannot be included, use
+
+ extern int Perl_hab_GET(void);
+
+instead.
+
+=item C<HMQ>
+
+There are two cases:
+
+=over
+
+=item *
+
+the extension needs an C<HMQ> only because some API will not work otherwise.
+Use C<serve = 0> below.
+
+=item *
+
+the extension needs an C<HMQ> since it wants to engage in a PM event loop.
+Use C<serve = 1> below.
+
+=back
+
+To get an C<HMQ>, the extension should call C<hmq = perl_hmq_GET(serve)> in C.
+After this call is performed, C<hmq> may be accessed as C<Perl_hmq>.
+
+To signal to Perl that HMQ is not needed any more, call
+C<perl_hmq_UNSET(serve)>. Perl process will automatically morph/unmorph itself
+into/from a PM process if HMQ is needed/not-needed. Perl will automatically
+enable/disable C<WM_QUIT> message during shutdown if the message queue is
+served/not-served.
+
+B<NOTE>. If during a shutdown there is a message queue which did not disable
+WM_QUIT, and which did not process the received WM_QUIT message, the
+shutdown will be automatically cancelled. Do not call C<perl_hmq_GET(1)>
+unless you are going to process messages on an orderly basis.
+
+=item * Treating errors reported by OS/2 API
+
+There are two principal conventions (it is useful to call them C<Dos*>
+and C<Win*> - though this part of the function signature is not always
+determined by the name of the API) of reporting the error conditions
+of OS/2 API. Most of C<Dos*> APIs report the error code as the result
+of the call (so 0 means success, and there are many types of errors).
+Most of C<Win*> API report success/fail via the result being
+C<TRUE>/C<FALSE>; to find the reason for the failure one should call
+WinGetLastError() API.
+
+Some C<Win*> entry points also overload a "meaningful" return value
+with the error indicator; having a 0 return value indicates an error.
+Yet some other C<Win*> entry points overload things even more, and 0
+return value may mean a successful call returning a valid value 0, as
+well as an error condition; in the case of a 0 return value one should
+call WinGetLastError() API to distinguish a successful call from a
+failing one.
+
+By convention, all the calls to OS/2 API should indicate their
+failures by resetting $^E. All the Perl-accessible functions which
+call OS/2 API may be broken into two classes: some die()s when an API
+error is encountered, the other report the error via a false return
+value (of course, this does not concern Perl-accessible functions
+which I<expect> a failure of the OS/2 API call, having some workarounds
+coded).
+
+Obviously, in the situation of the last type of the signature of an OS/2
+API, it is must more convenient for the users if the failure is
+indicated by die()ing: one does not need to check $^E to know that
+something went wrong. If, however, this solution is not desirable by
+some reason, the code in question should reset $^E to 0 before making
+this OS/2 API call, so that the caller of this Perl-accessible
+function has a chance to distinguish a success-but-0-return value from
+a failure. (One may return undef as an alternative way of reporting
+an error.)
+
+The macros to simplify this type of error propagation are
+
+=over
+
+=item C<CheckOSError(expr)>
+
+Returns true on error, sets $^E. Expects expr() be a call of
+C<Dos*>-style API.
+
+=item C<CheckWinError(expr)>
+
+Returns true on error, sets $^E. Expects expr() be a call of
+C<Win*>-style API.
+
+=item C<SaveWinError(expr)>
+
+Returns C<expr>, sets $^E from WinGetLastError() if C<expr> is false.
+
+=item C<SaveCroakWinError(expr,die,name1,name2)>
+
+Returns C<expr>, sets $^E from WinGetLastError() if C<expr> is false,
+and die()s if C<die> and $^E are true. The message to die is the
+concatenated strings C<name1> and C<name2>, separated by C<": "> from
+the contents of $^E.
+
+=item C<WinError_2_Perl_rc>
+
+Sets C<Perl_rc> to the return value of WinGetLastError().
+
+=item C<FillWinError>
+
+Sets C<Perl_rc> to the return value of WinGetLastError(), and sets $^E
+to the corresponding value.
+
+=item C<FillOSError(rc)>
+
+Sets C<Perl_rc> to C<rc>, and sets $^E to the corresponding value.
+
+=back
+
+=item * Loading DLLs and ordinals in DLLs
+
+Some DLLs are only present in some versions of OS/2, or in some
+configurations of OS/2. Some exported entry points are present only
+in DLLs shipped with some versions of OS/2. If these DLLs and entry
+points were linked directly for a Perl executable/DLL or from a Perl
+extensions, this binary would work only with the specified
+versions/setups. Even if these entry points were not needed, the
+I<load> of the executable (or DLL) would fail.
+
+For example, many newer useful APIs are not present in OS/2 v2; many
+PM-related APIs require DLLs not available on floppy-boot setup.
+
+To make these calls fail I<only when the calls are executed>, one
+should call these API via a dynamic linking API. There is a subsystem
+in Perl to simplify such type of calls. A large number of entry
+points available for such linking is provided (see C<entries_ordinals>
+- and also C<PMWIN_entries> - in F<os2ish.h>). These ordinals can be
+accessed via the APIs:
+
+ CallORD(), DeclFuncByORD(), DeclVoidFuncByORD(),
+ DeclOSFuncByORD(), DeclWinFuncByORD(), AssignFuncPByORD(),
+ DeclWinFuncByORD_CACHE(), DeclWinFuncByORD_CACHE_survive(),
+ DeclWinFuncByORD_CACHE_resetError_survive(),
+ DeclWinFunc_CACHE(), DeclWinFunc_CACHE_resetError(),
+ DeclWinFunc_CACHE_survive(), DeclWinFunc_CACHE_resetError_survive()
+
+See the header files and the C code in the supplied OS/2-related
+modules for the details on usage of these functions.
+
+Some of these functions also combine dynaloading semantic with the
+error-propagation semantic discussed above.
+
=back
=head1 Perl flavors
library F<perl.dll>, and with dynamic CRT DLL. This executable is a
VIO application.
-It can load perl dynamic extensions, and it can fork(). Unfortunately,
-with the current version of EMX it cannot fork() with dynamic
-extensions loaded (may be fixed by patches to EMX).
+It can load perl dynamic extensions, and it can fork().
B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
=head2 F<perl_.exe>
-This is a statically linked C<a.out>-style executable. It can fork(),
-but cannot load dynamic Perl extensions. The supplied executable has a
-lot of extensions prebuilt, thus there are situations when it can
-perform tasks not possible using F<perl.exe>, like fork()ing when
-having some standard extension loaded. This executable is a VIO
+This is a statically linked C<a.out>-style executable. It cannot
+load dynamic Perl extensions. The executable supplied in binary
+distributions has a lot of extensions prebuilt, thus the above restriction is
+important only if you use custom-built extensions. This executable is a VIO
application.
-B<Note.> A better behaviour could be obtained from C<perl.exe> if it
-were statically linked with standard I<Perl extensions>, but
-dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
-be able to fork() with standard extensions, I<and> would be able to
-dynamically load arbitrary extensions. Some changes to Makefiles and
-hint files should be necessary to achieve this.
-
-I<This is also the only executable with does not require OS/2.> The
+I<This is the only executable with does not require OS/2.> The
friends locked into C<M$> world would appreciate the fact that this
executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
appropriate extender. See L<"Other OSes">.
This is the same executable as F<perl___.exe>, but it is a PM
application.
-B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
-application are redirected to C<nul>. However, it is possible to see
+B<Note.> Usually (unless explicitly redirected during the startup)
+STDIN, STDERR, and STDOUT of a PM
+application are redirected to F<nul>. However, it is possible to I<see>
them if you start C<perl__.exe> from a PM program which emulates a
console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
possible> to use Perl debugger (see L<perldebug>) to debug your PM
-application.
+application (but beware of the message loop lockups - this will not
+work if you have a message queue to serve, unless you hook the serving
+into the getc() function of the debugger).
+
+Another way to see the output of a PM program is to run it as
+
+ pm_prog args 2>&1 | cat -
+
+with a shell I<different> from F<cmd.exe>, so that it does not create
+a link between a VIO session and the session of C<pm_porg>. (Such a link
+closes the VIO window.) E.g., this works with F<sh.exe> - or with Perl!
+
+ open P, 'pm_prog args 2>&1 |' or die;
+ print while <P>;
+
+The flavor F<perl__.exe> is required if you want to start your program without
+a VIO window present, but not C<detach>ed (run C<help detach> for more info).
+Very useful for extensions which use PM, like C<Perl/Tk> or C<OpenGL>.
-This flavor is required if you load extensions which use PM, like
-the forthcoming C<Perl/Tk>.
+Note also that the differences between PM and VIO executables are only
+in the I<default> behaviour. One can start I<any> executable in
+I<any> kind of session by using the arguments C</fs>, C</pm> or
+C</win> switches of the command C<start> (of F<CMD.EXE> or a similar
+shell). Alternatively, one can use the numeric first argument of the
+C<system> Perl function (see L<OS2::Process>).
=head2 F<perl___.exe>
Well, having several executables dynamically linked to the same huge
library has its advantages, but this would not substantiate the
-additional work to make it compile. The reason is stupid-but-quick
-"hard" dynamic linking used by OS/2.
+additional work to make it compile. The reason is the complicated-to-developers
+but very quick and convenient-to-users "hard" dynamic linking used by OS/2.
+
+There are two distinctive features of the dyna-linking model of OS/2:
+first, all the references to external functions are resolved at the compile time;
+second, there is no runtime fixup of the DLLs after they are loaded into memory.
+The first feature is an enormous advantage over other models: it avoids
+conflicts when several DLLs used by an application export entries with
+the same name. In such cases "other" models of dyna-linking just choose
+between these two entry points using some random criterion - with predictable
+disasters as results. But it is the second feature which requires the build
+of F<perl.dll>.
The address tables of DLLs are patched only once, when they are
-loaded. The addresses of entry points into DLLs are guaranteed to be
-the same for all programs which use the same DLL, which reduces the
-amount of runtime patching - once DLL is loaded, its code is
-read-only.
-
-While this allows some performance advantages, this makes life
-terrible for developers, since the above scheme makes it impossible
-for a DLL to be resolved to a symbol in the .EXE file, since this
-would need a DLL to have different relocations tables for the
-executables which use it.
+loaded. The addresses of the entry points into DLLs are guaranteed to be
+the same for all the programs which use the same DLL. This removes the
+runtime fixup - once DLL is loaded, its code is read-only.
-However, a Perl extension is forced to use some symbols from the perl
-executable, say to know how to find the arguments provided on the perl
-internal evaluation stack. The solution is that the main code of
-interpreter should be contained in a DLL, and the F<.EXE> file just loads
-this DLL into memory and supplies command-arguments.
+While this allows some (significant?) performance advantages, this makes life
+much harder for developers, since the above scheme makes it impossible
+for a DLL to be "linked" to a symbol in the F<.EXE> file. Indeed, this
+would need a DLL to have different relocations tables for the
+(different) executables which use this DLL.
+
+However, a dynamically loaded Perl extension is forced to use some symbols
+from the perl
+executable, e.g., to know how to find the arguments to the functions:
+the arguments live on the perl
+internal evaluation stack. The solution is to put the main code of
+the interpreter into a DLL, and make the F<.EXE> file which just loads
+this DLL into memory and supplies command-arguments. The extension DLL
+cannot link to symbols in F<.EXE>, but it has no problem linking
+to symbols in the F<.DLL>.
This I<greatly> increases the load time for the application (as well as
-the number of problems during compilation). Since interpreter is in a DLL,
-the CRT is basically forced to reside in a DLL as well (otherwise
-extensions would not be able to use CRT).
+complexity of the compilation). Since interpreter is in a DLL,
+the C RTL is basically forced to reside in a DLL as well (otherwise
+extensions would not be able to use CRT). There are some advantages if
+you use different flavors of perl, such as running F<perl.exe> and
+F<perl__.exe> simultaneously: they share the memory of F<perl.dll>.
+
+B<NOTE>. There is one additional effect which makes DLLs more wasteful:
+DLLs are loaded in the shared memory region, which is a scarse resource
+given the 512M barrier of the "standard" OS/2 virtual memory. The code of
+F<.EXE> files is also shared by all the processes which use the particular
+F<.EXE>, but they are "shared in the private address space of the process";
+this is possible because the address at which different sections
+of the F<.EXE> file are loaded is decided at compile-time, thus all the
+processes have these sections loaded at same addresses, and no fixup
+of internal links inside the F<.EXE> is needed.
+
+Since DLLs may be loaded at run time, to have the same mechanism for DLLs
+one needs to have the address range of I<any of the loaded> DLLs in the
+system to be available I<in all the processes> which did not load a particular
+DLL yet. This is why the DLLs are mapped to the shared memory region.
=head2 Why chimera build?
Current EMX environment does not allow DLLs compiled using Unixish
-C<a.out> format to export symbols for data. This forces C<omf>-style
-compile of F<perl.dll>.
+C<a.out> format to export symbols for data (or at least some types of
+
data). This forces C<omf>-style compile of F<perl.dll>.
Current EMX environment does not allow F<.EXE> files compiled in
C<omf> format to fork(). fork() is needed for exactly three Perl
=over 4
-=item explicit fork()
+=item *
+
+explicit fork() in the script,
-in the script, and
+=item *
-=item open FH, "|-"
+C<open FH, "|-">
-=item open FH, "-|"
+=item *
-opening pipes to itself.
+C<open FH, "-|">, in other words, opening pipes to itself.
=back
-While these operations are not questions of life and death, a lot of
-useful scripts use them. This forces C<a.out>-style compile of
+While these operations are not questions of life and death, they are
+needed for a lot of
+useful scripts. This forces C<a.out>-style compile of
F<perl.exe>.
Should be used if the perl library is moved from the default
location in preference to C<PERL(5)LIB>, since this would not leave wrong
-entries in <@INC>.
+entries in @INC. For example, if the compiled version of perl looks for @INC
+in F<f:/perllib/lib>, and you want to install the library in
+F<h:/opt/gnu>, do
+
+ set PERLLIB_PREFIX=f:/perllib/lib;h:/opt/gnu
+
+This will cause Perl with the prebuilt @INC of
+
+ f:/perllib/lib/5.00553/os2
+ f:/perllib/lib/5.00553
+ f:/perllib/lib/site_perl/5.00553/os2
+ f:/perllib/lib/site_perl/5.00553
+ .
+
+to use the following @INC:
+
+ h:/opt/gnu/5.00553/os2
+ h:/opt/gnu/5.00553
+ h:/opt/gnu/site_perl/5.00553/os2
+ h:/opt/gnu/site_perl/5.00553
+ .
=head2 C<PERL_BADLANG>
-If 1, perl ignores setlocale() failing. May be useful with some
+If 0, perl ignores setlocale() failing. May be useful with some
strange I<locale>s.
=head2 C<PERL_BADFREE>
-If 1, perl would not warn of in case of unwarranted free(). May be
-useful in conjunction with the module DB_File, since Berkeley DB
-memory handling code is buggy.
+If 0, perl would not warn of in case of unwarranted free(). With older
+perls this might be
+useful in conjunction with the module DB_File, which was buggy when
+dynamically linked and OMF-built.
+
+Should not be set with newer Perls, since this may hide some I<real> problems.
=head2 C<PERL_SH_DIR>
Specific for EMX port. Gives the directory part of the location for
F<sh.exe>.
+=head2 C<USE_PERL_FLOCK>
+
+Specific for EMX port. Since L<flock(3)> is present in EMX, but is not
+functional, it is emulated by perl. To disable the emulations, set
+environment variable C<USE_PERL_FLOCK=0>.
+
=head2 C<TMP> or C<TEMP>
-Specific for EMX port. Used as storage place for temporary files, most
-notably C<-e> scripts.
+Specific for EMX port. Used as storage place for temporary files.
=head1 Evolution
Here we list major changes which could make you by surprise.
+=head2 Text-mode filehandles
+
+Starting from version 5.8, Perl uses a builtin translation layer for
+text-mode files. This replaces the efficient well-tested EMX layer by
+some code which should be best characterized as a "quick hack".
+
+In addition to possible bugs and an inability to follow changes to the
+translation policy with off/on switches of TERMIO translation, this
+introduces a serious incompatible change: before sysread() on
+text-mode filehandles would go through the translation layer, now it
+would not.
+
=head2 Priorities
C<setpriority> and C<getpriority> are not compatible with earlier
ports by Andreas Kaiser. See C<"setpriority, getpriority">.
-=head2 DLL name mangling
+=head2 DLL name mangling: pre 5.6.2
With the release 5.003_01 the dynamically loadable libraries
-should be rebuilt. In particular, DLLs are now created with the names
+should be rebuilt when a different version of Perl is compiled. In particular,
+DLLs (including F<perl.dll>) are now created with the names
which contain a checksum, thus allowing workaround for OS/2 scheme of
caching DLLs.
+It may be possible to code a simple workaround which would
+
+=over
+
+=item *
+
+find the old DLLs looking through the old @INC;
+
+=item *
+
+mangle the names according to the scheme of new perl and copy the DLLs to
+these names;
+
+=item *
+
+edit the internal C<LX> tables of DLL to reflect the change of the name
+(probably not needed for Perl extension DLLs, since the internally coded names
+are not used for "specific" DLLs, they used only for "global" DLLs).
+
+=item *
+
+edit the internal C<IMPORT> tables and change the name of the "old"
+F<perl????.dll> to the "new" F<perl????.dll>.
+
+=back
+
+=head2 DLL name mangling: 5.6.2 and beyond
+
+In fact mangling of I<extension> DLLs was done due to misunderstanding
+of the OS/2 dynaloading model. OS/2 (effectively) maintains two
+different tables of loaded DLL:
+
+=over
+
+=item Global DLLs
+
+those loaded by the base name from C<LIBPATH>; including those
+associated at link time;
+
+=item specific DLLs
+
+loaded by the full name.
+
+=back
+
+When resolving a request for a global DLL, the table of already-loaded
+specific DLLs is (effectively) ignored; moreover, specific DLLs are
+I<always> loaded from the prescribed path.
+
+There is/was a minor twist which makes this scheme fragile: what to do
+with DLLs loaded from
+
+=over
+
+=item C<BEGINLIBPATH> and C<ENDLIBPATH>
+
+(which depend on the process)
+
+=item F<.> from C<LIBPATH>
+
+which I<effectively> depends on the process (although C<LIBPATH> is the
+same for all the processes).
+
+=back
+
+Unless C<LIBPATHSTRICT> is set to C<T> (and the kernel is after
+2000/09/01), such DLLs are considered to be global. When loading a
+global DLL it is first looked in the table of already-loaded global
+DLLs. Because of this the fact that one executable loaded a DLL from
+C<BEGINLIBPATH> and C<ENDLIBPATH>, or F<.> from C<LIBPATH> may affect
+I<which> DLL is loaded when I<another> executable requests a DLL with
+the same name. I<This> is the reason for version-specific mangling of
+the DLL name for perl DLL.
+
+Since the Perl extension DLLs are always loaded with the full path,
+there is no need to mangle their names in a version-specific ways:
+their directory already reflects the corresponding version of perl,
+and @INC takes into account binary compatibility with older version.
+Starting from C<5.6.2> the name mangling scheme is fixed to be the
+same as for Perl 5.005_53 (same as in a popular binary release). Thus
+new Perls will be able to I<resolve the names> of old extension DLLs
+if @INC allows finding their directories.
+
+However, this still does not guarantee that these DLL may be loaded.
+The reason is the mangling of the name of the I<Perl DLL>. And since
+the extension DLLs link with the Perl DLL, extension DLLs for older
+versions would load an older Perl DLL, and would most probably
+segfault (since the data in this DLL is not properly initialized).
+
+There is a partial workaround (which can be made complete with newer
+OS/2 kernels): create a forwarder DLL with the same name as the DLL of
+the older version of Perl, which forwards the entry points to the
+newer Perl's DLL. Make this DLL accessible on (say) the C<BEGINLIBPATH> of
+the new Perl executable. When the new executable accesses old Perl's
+extension DLLs, they would request the old Perl's DLL by name, get the
+forwarder instead, so effectively will link with the currently running
+(new) Perl DLL.
+
+This may break in two ways:
+
+=over
+
+=item *
+
+Old perl executable is started when a new executable is running has
+loaded an extension compiled for the old executable (ouph!). In this
+case the old executable will get a forwarder DLL instead of the old
+perl DLL, so would link with the new perl DLL. While not directly
+fatal, it will behave the same as new executable. This beats the whole
+purpose of explicitly starting an old executable.
+
+=item *
+
+A new executable loads an extension compiled for the old executable
+when an old perl executable is running. In this case the extension
+will not pick up the forwarder - with fatal results.
+
+=back
+
+With support for C<LIBPATHSTRICT> this may be circumvented - unless
+one of DLLs is started from F<.> from C<LIBPATH> (I do not know
+whether C<LIBPATHSTRICT> affects this case).
+
+B<REMARK>. Unless newer kernels allow F<.> in C<BEGINLIBPATH> (older
+do not), this mess cannot be completely cleaned. (It turns out that
+as of the beginning of 2002, F<.> is not allowed, but F<.\.> is - and
+it has the same effect.)
+
+
+B<REMARK>. C<LIBPATHSTRICT>, C<BEGINLIBPATH> and C<ENDLIBPATH> are
+not environment variables, although F<cmd.exe> emulates them on C<SET
+...> lines. From Perl they may be accessed by L<Cwd::extLibpath> and
+L<Cwd::extLibpath_set>.
+
+=head2 DLL forwarder generation
+
+Assume that the old DLL is named F<perlE0AC.dll> (as is one for
+5.005_53), and the new version is 5.6.1. Create a file
+F<perl5shim.def-leader> with
+
+ LIBRARY 'perlE0AC' INITINSTANCE TERMINSTANCE
+ DESCRIPTION '@#perl5-porters@perl.org:5.006001#@ Perl module for 5.00553 -> Perl 5.6.1 forwarder'
+ CODE LOADONCALL
+ DATA LOADONCALL NONSHARED MULTIPLE
+ EXPORTS
+
+modifying the versions/names as needed. Run
+
+ perl -wnle "next if 0../EXPORTS/; print qq( \"$1\") if /\"(\w+)\"/" perl5.def >lst
+
+in the Perl build directory (to make the DLL smaller replace perl5.def
+with the definition file for the older version of Perl if present).
+
+ cat perl5shim.def-leader lst >perl5shim.def
+ gcc -Zomf -Zdll -o perlE0AC.dll perl5shim.def -s -llibperl
+
+(ignore multiple C<warning L4085>).
+
=head2 Threading
-As of release 5.003_01 perl is linked to multithreaded CRT
-DLL. Perl itself is not multithread-safe, as is not perl
+As of release 5.003_01 perl is linked to multithreaded C RTL
+DLL. If perl itself is not compiled multithread-enabled, so will not be perl's
malloc(). However, extensions may use multiple thread on their own
risk.
-Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
+This was needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box, and
+link with DLLs for other useful libraries, which typically are compiled
+with C<-Zmt -Zcrtdll>.
=head2 Calls to external programs
whatever is the override, see L<"PERL_SH_DIR">.
Thus means that you need to get some copy of a F<sh.exe> as well (I
-use one from pdksh). The drive F: above is set up automatically during
+use one from pdksh). The path F<F:/bin> above is set up automatically during
the build to a correct value on the builder machine, but is
overridable at runtime,
B<Reasons:> a consensus on C<perl5-porters> was that perl should use
one non-overridable shell per platform. The obvious choices for OS/2
are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
-with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
+with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. This assures almost
100% compatibility with the scripts coming from *nix. As an added benefit
this works as well under DOS if you use DOS-enabled port of pdksh
(see L<"Prerequisites">).
B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
via fork()/exec(), and there is I<no> functioning exec() on
-OS/2. exec() is emulated by EMX by asyncroneous call while the caller
+OS/2. exec() is emulated by EMX by an asynchronous call while the caller
waits for child completion (to pretend that the C<pid> did not change). This
means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
which may lead to some resources taken from the system (even if we do
I will include it into distribution. I have no need for such a module, so
cannot test it.
+For the details of the current situation with calling external programs,
+see L<Starting OS/2 (and DOS) programs under Perl>. Set us mention a couple
+of features:
+
+=over 4
+
+=item *
+
+External scripts may be called by their basename. Perl will try the same
+extensions as when processing B<-S> command-line switch.
+
+=item *
+
+External scripts starting with C<#!> or C<extproc > will be executed directly,
+without calling the shell, by calling the program specified on the rest of
+the first line.
+
+=back
+
=head2 Memory allocation
Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
-for speed, but perl is not, since its malloc is lightning-fast.
-Unfortunately, it is also quite frivolous with memory usage as well.
-
-Since kitchen-top machines are usually low on memory, perl is compiled with
-all the possible memory-saving options. This probably makes perl's
-malloc() as greedy with memory as the neighbor's malloc(), but still
-much quickier. Note that this is true only for a "typical" usage,
-it is possible that the perl malloc will be worse for some very special usage.
+for speed, but perl is not, since its malloc is lightning-fast.
+Perl-memory-usage-tuned benchmarks show that Perl's malloc is 5 times quicker
+than EMX one. I do not have convincing data about memory footprint, but
+a (pretty random) benchmark showed that Perl's one is 5% better.
Combination of perl's malloc() and rigid DLL name resolution creates
a special problem with library functions which expect their return value to
the prefix C<emx_> added. (Currently only DLL perl has this, it should
propagate to F<perl_.exe> shortly.)
+=head2 Threads
+
+One can build perl with thread support enabled by providing C<-D usethreads>
+option to F<Configure>. Currently OS/2 support of threads is very
+preliminary.
+
+Most notable problems:
+
+=over 4
+
+=item C<COND_WAIT>
+
+may have a race condition (but probably does not due to edge-triggered
+nature of OS/2 Event semaphores). (Needs a reimplementation (in terms of chaining
+waiting threads, with the linked list stored in per-thread structure?)?)
+
+=item F<os2.c>
+
+has a couple of static variables used in OS/2-specific functions. (Need to be
+moved to per-thread structure, or serialized?)
+
+=back
+
+Note that these problems should not discourage experimenting, since they
+have a low probability of affecting small programs.
+
+=head1 BUGS
+
+This description is not updated often (since 5.6.1?), see F<./os2/Changes>
+(L<perlos2delta>) for more info.
+
=cut
OS/2 extensions
=head1 AUTHOR
-Ilya Zakharevich, ilya@math.ohio-state.edu
+Ilya Zakharevich, cpan@ilyaz.org
=head1 SEE ALSO
https://perl5.git.perl.org / perl5.git / blobdiff