1 If you read this file _as_is_, just ignore the funny characters you
2 see. It is written in the POD format (see perlpod manpage) which is
3 specially designed to be readable as is.
7 perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.
11 One can read this document in the following formats:
18 to list some (not all may be available simultaneously), or it may
19 be read I<as is>: either as F<README.os2>, or F<pod/perlos2.pod>.
21 To read the F<.INF> version of documentation (B<very> recommended)
22 outside of OS/2, one needs an IBM's reader (may be available on IBM
23 ftp sites (?) (URL anyone?)) or shipped with PC DOS 7.0 and IBM's
26 A copy of a Win* viewer is contained in the "Just add OS/2 Warp" package
28 ftp://ftp.software.ibm.com/ps/products/os2/tools/jaow/jaow.zip
30 in F<?:\JUST_ADD\view.exe>. This gives one an access to EMX's
31 F<.INF> docs as well (text form is available in F</emx/doc> in
38 perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.
46 - Starting Perl programs under OS/2 (and DOS and...)
47 - Starting OS/2 (and DOS) programs under Perl
48 Frequently asked questions
49 - I cannot run external programs
50 - I cannot embed perl into my program, or use perl.dll from my program.
51 - `` and pipe-open do not work under DOS.
52 - Cannot start find.exe "pattern" file
54 - Automatic binary installation
55 - Manual binary installation
57 Accessing documentation
68 - Application of the patches
72 - Installing the built perl
75 - Some / became \ in pdksh.
76 - 'errno' - unresolved external
78 - Some problem (forget which ;-)
79 - Library ... not found
81 Specific (mis)features of EMX port
82 - setpriority, getpriority
84 - extproc on the first line
95 - Why dynamic linking?
107 - Calls to external programs
116 The target is to make OS/2 the best supported platform for
117 using/building/developing Perl and I<Perl applications>, as well as
118 make Perl the best language to use under OS/2. The secondary target is
119 to try to make this work under DOS and Win* as well (but not B<too> hard).
121 The current state is quite close to this target. Known limitations:
127 Some *nix programs use fork() a lot, but currently fork() is not
128 supported after I<use>ing dynamically loaded extensions.
132 You need a separate perl executable F<perl__.exe> (see L<perl__.exe>)
133 to use PM code in your application (like the forthcoming Perl/Tk).
137 There is no simple way to access WPS objects. The only way I know
138 is via C<OS2::REXX> extension (see L<OS2::REXX>), and we do not have access to
139 convenience methods of Object-REXX. (Is it possible at all? I know
140 of no Object-REXX API.)
144 Please keep this list up-to-date by informing me about other items.
148 Since OS/2 port of perl uses a remarkable EMX environment, it can
149 run (and build extensions, and - possibly - be build itself) under any
150 environment which can run EMX. The current list is DOS,
151 DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors,
152 only one works, see L<"perl_.exe">.
154 Note that not all features of Perl are available under these
155 environments. This depends on the features the I<extender> - most
156 probably RSX - decided to implement.
158 Cf. L<Prerequisites>.
166 EMX runtime is required (may be substituted by RSX). Note that
167 it is possible to make F<perl_.exe> to run under DOS without any
168 external support by binding F<emx.exe>/F<rsx.exe> to it, see L<emxbind>. Note
169 that under DOS for best results one should use RSX runtime, which
170 has much more functions working (like C<fork>, C<popen> and so on). In
171 fact RSX is required if there is no VCPI present. Note the
174 Only the latest runtime is supported, currently C<0.9c>. Perl may run
175 under earlier versions of EMX, but this is not tested.
177 One can get different parts of EMX from, say
179 ftp://ftp.cdrom.com/pub/os2/emx0.9c/
180 ftp://hobbes.nmsu.edu/os2/unix/gnu/
182 The runtime component should have the name F<emxrt.zip>.
184 B<NOTE>. It is enough to have F<emx.exe>/F<rsx.exe> on your path. One
185 does not need to specify them explicitly (though this
193 To run Perl on DPMI platforms one needs RSX runtime. This is
194 needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see
195 L<"Other OSes">). RSX would not work with VCPI
196 only, as EMX would, it requires DMPI.
198 Having RSX and the latest F<sh.exe> one gets a fully functional
199 B<*nix>-ish environment under DOS, say, C<fork>, C<``> and
200 pipe-C<open> work. In fact, MakeMaker works (for static build), so one
201 can have Perl development environment under DOS.
203 One can get RSX from, say
205 ftp://ftp.cdrom.com/pub/os2/emx0.9c/contrib
206 ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc
208 Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
210 The latest F<sh.exe> with DOS hooks is available at
212 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.exe
216 Perl does not care about file systems, but to install the whole perl
217 library intact one needs a file system which supports long file names.
219 Note that if you do not plan to build the perl itself, it may be
220 possible to fool EMX to truncate file names. This is not supported,
221 read EMX docs to see how to do it.
225 To start external programs with complicated command lines (like with
226 pipes in between, and/or quoting of arguments), Perl uses an external
227 shell. With EMX port such shell should be named <sh.exe>, and located
228 either in the wired-in-during-compile locations (usually F<F:/bin>),
229 or in configurable location (see L<"PERL_SH_DIR">).
231 For best results use EMX pdksh. The soon-to-be-available standard
232 binary (5.2.12?) runs under DOS (with L<RSX>) as well, meanwhile use
235 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.exe
239 =head2 Starting Perl programs under OS/2 (and DOS and...)
241 Start your Perl program F<foo.pl> with arguments C<arg1 arg2 arg3> the
242 same way as on any other platform, by
244 perl foo.pl arg1 arg2 arg3
246 If you want to specify perl options C<-my_opts> to the perl itself (as
247 opposed to to your program), use
249 perl -my_opts foo.pl arg1 arg2 arg3
251 Alternately, if you use OS/2-ish shell, like CMD or 4os2, put
252 the following at the start of your perl script:
254 extproc perl -S -my_opts
256 rename your program to F<foo.cmd>, and start it by typing
260 Note that because of stupid OS/2 limitations the full path of the perl
261 script is not available when you use C<extproc>, thus you are forced to
262 use C<-S> perl switch, and your script should be on path. As a plus
263 side, if you know a full path to your script, you may still start it
266 perl ../../blah/foo.cmd arg1 arg2 arg3
268 (note that the argument C<-my_opts> is taken care of by the C<extproc> line
269 in your script, see L<C<extproc> on the first line>).
271 To understand what the above I<magic> does, read perl docs about C<-S>
272 switch - see L<perlrun>, and cmdref about C<extproc>:
279 or whatever method you prefer.
281 There are also endless possibilities to use I<executable extensions> of
282 4os2, I<associations> of WPS and so on... However, if you use
283 *nixish shell (like F<sh.exe> supplied in the binary distribution),
284 you need to follow the syntax specified in L<perlrun/"Switches">.
286 =head2 Starting OS/2 (and DOS) programs under Perl
288 This is what system() (see L<perlfunc/system>), C<``> (see
289 L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
290 are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
293 Note however that to use some of these operators you need to have a
294 sh-syntax shell installed (see L<"Pdksh">,
295 L<"Frequently asked questions">), and perl should be able to find it
296 (see L<"PERL_SH_DIR">).
298 The only cases when the shell is not used is the multi-argument
299 system() (see L<perlfunc/system>)/exec() (see L<perlfunc/exec>), and
300 one-argument version thereof without redirection and shell
303 =head1 Frequently asked questions
305 =head2 I cannot run external programs
311 Did you run your programs with C<-w> switch? See
312 L<Starting OS/2 (and DOS) programs under Perl>.
316 Do you try to run I<internal> shell commands, like C<`copy a b`>
317 (internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
318 need to specify your shell explicitly, like C<`cmd /c copy a b`>,
319 since Perl cannot deduce which commands are internal to your shell.
323 =head2 I cannot embed perl into my program, or use F<perl.dll> from my
328 =item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
330 If not, you need to build a stand-alone DLL for perl. Contact me, I
331 did it once. Sockets would not work, as a lot of other stuff.
333 =item Did you use L<ExtUtils::Embed>?
335 I had reports it does not work. Somebody would need to fix it.
339 =head2 C<``> and pipe-C<open> do not work under DOS.
341 This may a variant of just L<"I cannot run external programs">, or a
342 deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
343 for these commands to work, and you may need a port of F<sh.exe> which
344 understands command arguments. One of such ports is listed in
345 L<"Prerequisites"> under RSX. Do not forget to set variable
346 C<L<"PERL_SH_DIR">> as well.
348 DPMI is required for RSX.
350 =head2 Cannot start C<find.exe "pattern" file>
354 system 'cmd', '/c', 'find "pattern" file';
355 `cmd /c 'find "pattern" file'`
357 This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
358 C<perl.exe>, but this is a price to pay if you want to use
359 non-conforming program. In fact F<find.exe> cannot be started at all
360 using C library API only. Otherwise the following command-lines were
368 =head2 Automatic binary installation
370 The most convenient way of installing perl is via perl installer
371 F<install.exe>. Just follow the instructions, and 99% of the
372 installation blues would go away.
374 Note however, that you need to have F<unzip.exe> on your path, and
375 EMX environment I<running>. The latter means that if you just
376 installed EMX, and made all the needed changes to F<Config.sys>,
377 you may need to reboot in between. Check EMX runtime by running
381 A folder is created on your desktop which contains some useful
384 B<Things not taken care of by automatic binary installation:>
388 =item C<PERL_BADLANG>
390 may be needed if you change your codepage I<after> perl installation,
391 and the new value is not supported by EMX. See L<"PERL_BADLANG">.
393 =item C<PERL_BADFREE>
395 see L<"PERL_BADFREE">.
399 This file resides somewhere deep in the location you installed your
400 perl library, find it out by
402 perl -MConfig -le "print $INC{'Config.pm'}"
404 While most important values in this file I<are> updated by the binary
405 installer, some of them may need to be hand-edited. I know no such
406 data, please keep me informed if you find one.
410 B<NOTE>. Because of a typo the binary installer of 5.00305
411 would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
412 remove this variable and put C<L<PERL_SH_DIR>> instead.
414 =head2 Manual binary installation
416 As of version 5.00305, OS/2 perl binary distribution comes split
417 into 11 components. Unfortunately, to enable configurable binary
418 installation, the file paths in the zip files are not absolute, but
419 relative to some directory.
421 Note that the extraction with the stored paths is still necessary
422 (default with unzip, specify C<-d> to pkunzip). However, you
423 need to know where to extract the files. You need also to manually
424 change entries in F<Config.sys> to reflect where did you put the
425 files. Note that if you have some primitive unzipper (like
426 pkunzip), you may get a lot of warnings/errors during
427 unzipping. Upgrade to C<(w)unzip>.
429 Below is the sample of what to do to reproduce the configuration on my
434 =item Perl VIO and PM executables (dynamically linked)
436 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
437 unzip perl_exc.zip *.dll -d f:/emx.add/dll
439 (have the directories with C<*.exe> on PATH, and C<*.dll> on
442 =item Perl_ VIO executable (statically linked)
444 unzip perl_aou.zip -d f:/emx.add/bin
446 (have the directory on PATH);
448 =item Executables for Perl utilities
450 unzip perl_utl.zip -d f:/emx.add/bin
452 (have the directory on PATH);
454 =item Main Perl library
456 unzip perl_mlb.zip -d f:/perllib/lib
458 If this directory is preserved, you do not need to change
459 anything. However, for perl to find it if it is changed, you need to
460 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
462 =item Additional Perl modules
464 unzip perl_ste.zip -d f:/perllib/lib/site_perl
466 If you do not change this directory, do nothing. Otherwise put this
467 directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
468 variable. Do not use C<PERL5LIB> unless you have it set already. See
469 L<perl/"ENVIRONMENT">.
471 =item Tools to compile Perl modules
473 unzip perl_blb.zip -d f:/perllib/lib
475 If this directory is preserved, you do not need to change
476 anything. However, for perl to find it if it is changed, you need to
477 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
479 =item Manpages for Perl and utilities
481 unzip perl_man.zip -d f:/perllib/man
483 This directory should better be on C<MANPATH>. You need to have a
484 working man to access these files.
486 =item Manpages for Perl modules
488 unzip perl_mam.zip -d f:/perllib/man
490 This directory should better be on C<MANPATH>. You need to have a
491 working man to access these files.
493 =item Source for Perl documentation
495 unzip perl_pod.zip -d f:/perllib/lib
497 This is used by by C<perldoc> program (see L<perldoc>), and may be used to
498 generate HTML documentation usable by WWW browsers, and
499 documentation in zillions of other formats: C<info>, C<LaTeX>,
500 C<Acrobat>, C<FrameMaker> and so on.
502 =item Perl manual in F<.INF> format
504 unzip perl_inf.zip -d d:/os2/book
506 This directory should better be on C<BOOKSHELF>.
510 unzip perl_sh.zip -d f:/bin
512 This is used by perl to run external commands which explicitly
513 require shell, like the commands using I<redirection> and I<shell
514 metacharacters>. It is also used instead of explicit F</bin/sh>.
516 Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
519 B<Note.> It may be possible to use some other sh-compatible shell
524 After you installed the components you needed and updated the
525 F<Config.sys> correspondingly, you need to hand-edit
526 F<Config.pm>. This file resides somewhere deep in the location you
527 installed your perl library, find it out by
529 perl -MConfig -le "print $INC{'Config.pm'}"
531 You need to correct all the entries which look like file paths (they
532 currently start with C<f:/>).
536 The automatic and manual perl installation leave precompiled paths
537 inside perl executables. While these paths are overwriteable (see
538 L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
539 binary editing of paths inside the executables/DLLs.
541 =head1 Accessing documentation
543 Depending on how you built/installed perl you may have (otherwise
544 identical) Perl documentation in the following formats:
546 =head2 OS/2 F<.INF> file
548 Most probably the most convenient form. Under OS/2 view it as
553 view perl ExtUtils::MakeMaker
555 (currently the last two may hit a wrong location, but this may improve
556 soon). Under Win* see L<"SYNOPSIS">.
558 If you want to build the docs yourself, and have I<OS/2 toolkit>, run
562 in F</perllib/lib/pod> directory, then
566 (Expect a lot of errors during the both steps.) Now move it on your
571 If you have perl documentation in the source form, perl utilities
572 installed, and GNU groff installed, you may use
576 perldoc ExtUtils::MakeMaker
578 to access the perl documentation in the text form (note that you may get
579 better results using perl manpages).
581 Alternately, try running pod2text on F<.pod> files.
585 If you have man installed on your system, and you installed perl
586 manpages, use something like this:
590 man ExtUtils.MakeMaker
592 to access documentation for different components of Perl. Start with
596 Note that dot (F<.>) is used as a package separator for documentation
597 for packages, and as usual, sometimes you need to give the section - C<3>
598 above - to avoid shadowing by the I<less(1) manpage>.
600 Make sure that the directory B<above> the directory with manpages is
601 on our C<MANPATH>, like this
603 set MANPATH=c:/man;f:/perllib/man
607 If you have some WWW browser available, installed the Perl
608 documentation in the source form, and Perl utilities, you can build
609 HTML docs. Cd to directory with F<.pod> files, and do like this
611 cd f:/perllib/lib/pod
614 After this you can direct your browser the file F<perl.html> in this
615 directory, and go ahead with reading docs, like this:
617 explore file:///f:/perllib/lib/pod/perl.html
619 Alternatively you may be able to get these docs prebuilt from CPAN.
621 =head2 GNU C<info> files
623 Users of Emacs would appreciate it very much, especially with
624 C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
625 or, alternately, prebuilt info pages.
629 for C<Acrobat> are available on CPAN (for slightly old version of
634 can be constructed using C<pod2latex>.
638 Here we discuss how to build Perl under OS/2. There is an alternative
639 (but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
643 You need to have the latest EMX development environment, the full
644 GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
645 earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
651 ). You need the latest version of F<pdksh> installed as F<sh.exe>.
653 Possible locations to get this from are
655 ftp://hobbes.nmsu.edu/os2/unix/gnu/
656 ftp://ftp.cdrom.com/pub/os2/unix/
657 ftp://ftp.cdrom.com/pub/os2/dev32/
658 ftp://ftp.cdrom.com/pub/os2/emx0.9c/
661 Make sure that no copies or perl are currently running. Later steps
662 of the build may fail since an older version of perl.dll loaded into
665 Also make sure that you have F</tmp> directory on the current drive,
666 and F<.> directory in your C<LIBPATH>. One may try to correct the
671 if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
673 Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
674 script in F</emx/lib> directory.
676 Check that you have link386 installed. It comes standard with OS/2,
677 but may be not installed due to customization. If typing
681 shows you do not have it, do I<Selective install>, and choose C<Link
682 object modules> in I<Optional system utilities/More>. If you get into
683 link386, press C<Ctrl-C>.
685 =head2 Getting perl source
687 You need to fetch the latest perl source (including developers
688 releases). With some probability it is located in
690 http://www.perl.com/CPAN/src/5.0
691 http://www.perl.com/CPAN/src/5.0/unsupported
693 If not, you may need to dig in the indices to find it in the directory
694 of the current maintainer.
696 Quick cycle of developers release may break the OS/2 build time to
699 http://www.perl.com/CPAN/ports/os2/ilyaz/
701 may indicate the latest release which was publicly released by the
702 maintainer. Note that the release may include some additional patches
703 to apply to the current source of perl.
707 tar vzxf perl5.00409.tar.gz
709 You may see a message about errors while extracting F<Configure>. This is
710 because there is a conflict with a similarly-named file F<configure>.
712 Change to the directory of extraction.
714 =head2 Application of the patches
716 You need to apply the patches in F<./os2/diff.*> and
717 F<./os2/POSIX.mkfifo> like this:
719 gnupatch -p0 < os2\POSIX.mkfifo
720 gnupatch -p0 < os2\diff.configure
722 You may also need to apply the patches supplied with the binary
723 distribution of perl.
725 Note also that the F<db.lib> and F<db.a> from the EMX distribution
726 are not suitable for multi-threaded compile (note that currently perl
727 is not multithread-safe, but is compiled as multithreaded for
728 compatibility with XFree86-OS/2). Get a corrected one from
730 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
734 You may look into the file F<./hints/os2.sh> and correct anything
735 wrong you find there. I do not expect it is needed anywhere.
739 sh Configure -des -D prefix=f:/perllib
741 C<prefix> means: where to install the resulting perl library. Giving
742 correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
743 see L<"PERLLIB_PREFIX">.
745 I<Ignore the message about missing C<ln>, and about C<-c> option to
746 tr>. In fact if you can trace where the latter spurious warning
747 comes from, please inform me.
753 At some moment the built may die, reporting a I<version mismatch> or
754 I<unable to run F<perl>>. This means that most of the build has been
755 finished, and it is the time to move the constructed F<perl.dll> to
756 some I<absolute> location in LIBPATH. After this is done the build
757 should finish without a lot of fuss. I<One can avoid the interruption
758 if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
759 probably this is not needed anymore, since F<miniperl.exe> is linked
762 Warnings which are safe to ignore: I<mkfifo() redefined> inside
771 Some tests (4..6) should fail. Some perl invocations should end in a
772 segfault (system error C<SYS3175>). To get finer error reports,
777 The report you get may look like
779 Failed Test Status Wstat Total Fail Failed List of failed
780 ---------------------------------------------------------------
781 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
782 lib/io_pipe.t 3 768 6 ?? % ??
783 lib/io_sock.t 3 768 5 ?? % ??
784 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
785 Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
787 Note that using `make test' target two more tests may fail: C<op/exec:1>
788 because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
789 that the buffers are not flushed on C<_exit> (this is a bug in the test
790 which assumes that tty output is buffered).
792 I submitted a patch to EMX which makes it possible to fork() with EMX
793 dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
794 that soon the number of failing tests may decrease yet more.
796 However, the test F<lib/io_udp.t> is disabled, since it never terminates, I
797 do not know why. Comments/fixes welcome.
799 The reasons for failed tests are:
805 Checks I<file system> operations. Tests:
811 Check C<link()> and C<inode count> - nonesuch under OS/2.
815 Checks C<atime> and C<mtime> of C<stat()> - I could not understand this test.
819 Checks C<truncate()> on a filehandle just opened for write - I do not
820 know why this should or should not work.
824 =item F<lib/io_pipe.t>
826 Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
827 dynamic extension loaded - unsupported now.
829 =item F<lib/io_sock.t>
831 Checks C<IO::Socket> module. Some feature of EMX - test fork()s
832 with dynamic extension loaded - unsupported now.
836 Checks C<stat()>. Tests:
842 Checks C<inode count> - nonesuch under OS/2.
846 Checks C<mtime> and C<ctime> of C<stat()> - I could not understand this test.
850 Checks C<-x> - determined by the file extension only under OS/2.
858 Checks C<-t> of F</dev/null>. Should not fail!
864 In addition to errors, you should get a lot of warnings.
868 =item A lot of `bad free'
870 in databases related to Berkeley DB. This is a confirmed bug of
871 DB. You may disable this warnings, see L<"PERL_BADFREE">.
873 =item Process terminated by SIGTERM/SIGINT
875 This is a standard message issued by OS/2 applications. *nix
876 applications die in silence. It is considered a feature. One can
877 easily disable this by appropriate sighandlers.
879 However the test engine bleeds these message to screen in unexpected
880 moments. Two messages of this kind I<should> be present during
883 =item F<*/sh.exe>: ln: not found
885 =item C<ls>: /dev: No such file or directory
887 The last two should be self-explanatory. The test suite discovers that
888 the system it runs on is not I<that much> *nixish.
892 A lot of `bad free'... in databases, bug in DB confirmed on other
893 platforms. You may disable it by setting PERL_BADFREE environment variable
896 =head2 Installing the built perl
902 It would put the generated files into needed locations. Manually put
903 F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
904 PATH, F<perl.dll> to a location on your LIBPATH.
908 make cmdscripts INSTALLCMDDIR=d:/ir/on/path
910 to convert perl utilities to F<.cmd> files and put them on
911 PATH. You need to put F<.EXE>-utilities on path manually. They are
912 installed in C<$prefix/bin>, here C<$prefix> is what you gave to
913 F<Configure>, see L<Making>.
915 =head2 C<a.out>-style build
917 Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
926 Manually put F<perl_.exe> to a location on your PATH.
928 Since C<perl_> has the extensions prebuilt, it does not suffer from
929 the I<dynamic extensions + fork()> syndrome, thus the failing tests
932 Failed Test Status Wstat Total Fail Failed List of failed
933 ---------------------------------------------------------------
934 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
935 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
936 Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
938 B<Note.> The build process for C<perl_> I<does not know> about all the
939 dependencies, so you should make sure that anything is up-to-date,
948 =head2 Some C</> became C<\> in pdksh.
950 You have a very old pdksh. See L<Prerequisites>.
952 =head2 C<'errno'> - unresolved external
954 You do not have MT-safe F<db.lib>. See L<Prerequisites>.
956 =head2 Problems with tr
958 reported with very old version of tr.
960 =head2 Some problem (forget which ;-)
962 You have an older version of F<perl.dll> on your LIBPATH, which
963 broke the build of extensions.
965 =head2 Library ... not found
967 You did not run C<omflibs>. See L<Prerequisites>.
969 =head2 Segfault in make
971 You use an old version of GNU make. See L<Prerequisites>.
973 =head1 Specific (mis)features of OS/2 port
975 =head2 C<setpriority>, C<getpriority>
977 Note that these functions are compatible with *nix, not with the older
978 ports of '94 - 95. The priorities are absolute, go from 32 to -95,
979 lower is quicker. 0 is the default priority.
983 Multi-argument form of C<system()> allows an additional numeric
984 argument. The meaning of this argument is described in
987 =head2 C<extproc> on the first line
989 If the first chars of a script are C<"extproc ">, this line is treated
990 as C<#!>-line, thus all the switches on this line are processed (twice
991 if script was started via cmd.exe).
993 =head2 Additional modules:
995 L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. This
996 modules provide access to additional numeric argument for C<system>,
997 to DLLs having functions with REXX signature and to REXX runtime, to
998 OS/2 databases in the F<.INI> format, and to Extended Attributes.
1000 Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
1001 C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
1003 =head2 Prebuilt methods:
1007 =item C<File::Copy::syscopy>
1009 used by C<File::Copy::copy>, see L<File::Copy/copy>.
1011 =item C<DynaLoader::mod2fname>
1013 used by C<DynaLoader> for DLL name mangling.
1015 =item C<Cwd::current_drive()>
1019 =item C<Cwd::sys_chdir(name)>
1021 leaves drive as it is.
1023 =item C<Cwd::change_drive(name)>
1026 =item C<Cwd::sys_is_absolute(name)>
1028 means has drive letter and is_rooted.
1030 =item C<Cwd::sys_is_rooted(name)>
1032 means has leading C<[/\\]> (maybe after a drive-letter:).
1034 =item C<Cwd::sys_is_relative(name)>
1036 means changes with current dir.
1038 =item C<Cwd::sys_cwd(name)>
1040 Interface to cwd from EMX. Used by C<Cwd::cwd>.
1042 =item C<Cwd::sys_abspath(name, dir)>
1044 Really really odious function to implement. Returns absolute name of
1045 file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1048 =item C<Cwd::extLibpath([type])
1050 Get current value of extended library search path. If C<type> is
1051 present and I<true>, works with END_LIBPATH, otherwise with
1054 =item C<Cwd::extLibpath_set( path [, type ] )>
1056 Set current value of extended library search path. If C<type> is
1057 present and I<true>, works with END_LIBPATH, otherwise with
1062 (Note that some of these may be moved to different libraries -
1072 Since <flock> is present in EMX, but is not functional, the same is
1073 true for perl. Here is the list of things which may be "broken" on
1074 EMX (from EMX docs):
1076 - The functions recvmsg(), sendmsg(), and socketpair() are not
1078 - sock_init() is not required and not implemented.
1079 - flock() is not yet implemented (dummy function).
1081 Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1085 waitpid() is not implemented for negative values of PID.
1087 Note that C<kill -9> does not work with the current version of EMX.
1091 Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
1092 of F<sh.exe> plague perl as well.
1094 In particular, uppercase letters do not work in C<[...]>-patterns with
1099 =head2 Modifications
1101 Perl modifies some standard C library calls in the following ways:
1107 C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
1111 is created using C<TMP> or C<TEMP> environment variable, via
1116 If the current directory is not writable, file is created using modified
1117 C<tmpnam>, so there may be a race condition.
1121 a dummy implementation.
1125 C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1131 Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
1132 same basket (though EMX environment tries hard to overcome this
1133 limitations, so the situation may somehow improve). There are 4
1134 executables for Perl provided by the distribution:
1138 The main workhorse. This is a chimera executable: it is compiled as an
1139 C<a.out>-style executable, but is linked with C<omf>-style dynamic
1140 library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1143 It can load perl dynamic extensions, and it can fork(). Unfortunately,
1144 with the current version of EMX it cannot fork() with dynamic
1145 extensions loaded (may be fixed by patches to EMX).
1147 B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1151 This is a statically linked C<a.out>-style executable. It can fork(),
1152 but cannot load dynamic Perl extensions. The supplied executable has a
1153 lot of extensions prebuilt, thus there are situations when it can
1154 perform tasks not possible using F<perl.exe>, like fork()ing when
1155 having some standard extension loaded. This executable is a VIO
1158 B<Note.> A better behaviour could be obtained from C<perl.exe> if it
1159 were statically linked with standard I<Perl extensions>, but
1160 dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
1161 be able to fork() with standard extensions, I<and> would be able to
1162 dynamically load arbitrary extensions. Some changes to Makefiles and
1163 hint files should be necessary to achieve this.
1165 I<This is also the only executable with does not require OS/2.> The
1166 friends locked into C<M$> world would appreciate the fact that this
1167 executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
1168 appropriate extender. See L<"Other OSes">.
1170 =head2 F<perl__.exe>
1172 This is the same executable as F<perl___.exe>, but it is a PM
1175 B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
1176 application are redirected to C<nul>. However, it is possible to see
1177 them if you start C<perl__.exe> from a PM program which emulates a
1178 console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
1179 possible> to use Perl debugger (see L<perldebug>) to debug your PM
1182 This flavor is required if you load extensions which use PM, like
1183 the forthcoming C<Perl/Tk>.
1185 =head2 F<perl___.exe>
1187 This is an C<omf>-style executable which is dynamically linked to
1188 F<perl.dll> and CRT DLL. I know no advantages of this executable
1189 over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1190 that the build process is not so convoluted as with C<perl.exe>.
1192 It is a VIO application.
1194 =head2 Why strange names?
1196 Since Perl processes the C<#!>-line (cf.
1197 L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1198 L<perldiag/"Not a perl script">,
1199 L<perldiag/"No Perl script found in input">), it should know when a
1200 program I<is a Perl>. There is some naming convention which allows
1201 Perl to distinguish correct lines from wrong ones. The above names are
1202 almost the only names allowed by this convention which do not contain
1203 digits (which have absolutely different semantics).
1205 =head2 Why dynamic linking?
1207 Well, having several executables dynamically linked to the same huge
1208 library has its advantages, but this would not substantiate the
1209 additional work to make it compile. The reason is stupid-but-quick
1210 "hard" dynamic linking used by OS/2.
1212 The address tables of DLLs are patched only once, when they are
1213 loaded. The addresses of entry points into DLLs are guaranteed to be
1214 the same for all programs which use the same DLL, which reduces the
1215 amount of runtime patching - once DLL is loaded, its code is
1218 While this allows some performance advantages, this makes life
1219 terrible for developers, since the above scheme makes it impossible
1220 for a DLL to be resolved to a symbol in the .EXE file, since this
1221 would need a DLL to have different relocations tables for the
1222 executables which use it.
1224 However, a Perl extension is forced to use some symbols from the perl
1225 executable, say to know how to find the arguments provided on the perl
1226 internal evaluation stack. The solution is that the main code of
1227 interpreter should be contained in a DLL, and the F<.EXE> file just loads
1228 this DLL into memory and supplies command-arguments.
1230 This I<greatly> increases the load time for the application (as well as
1231 the number of problems during compilation). Since interpreter is in a DLL,
1232 the CRT is basically forced to reside in a DLL as well (otherwise
1233 extensions would not be able to use CRT).
1235 =head2 Why chimera build?
1237 Current EMX environment does not allow DLLs compiled using Unixish
1238 C<a.out> format to export symbols for data. This forces C<omf>-style
1239 compile of F<perl.dll>.
1241 Current EMX environment does not allow F<.EXE> files compiled in
1242 C<omf> format to fork(). fork() is needed for exactly three Perl
1247 =item explicit fork()
1255 opening pipes to itself.
1259 While these operations are not questions of life and death, a lot of
1260 useful scripts use them. This forces C<a.out>-style compile of
1266 Here we list environment variables with are either OS/2- and DOS- and
1267 Win*-specific, or are more important under OS/2 than under other OSes.
1269 =head2 C<PERLLIB_PREFIX>
1271 Specific for EMX port. Should have the form
1279 If the beginning of some prebuilt path matches F<path1>, it is
1280 substituted with F<path2>.
1282 Should be used if the perl library is moved from the default
1283 location in preference to C<PERL(5)LIB>, since this would not leave wrong
1286 =head2 C<PERL_BADLANG>
1288 If 1, perl ignores setlocale() failing. May be useful with some
1291 =head2 C<PERL_BADFREE>
1293 If 1, perl would not warn of in case of unwarranted free(). May be
1294 useful in conjunction with the module DB_File, since Berkeley DB
1295 memory handling code is buggy.
1297 =head2 C<PERL_SH_DIR>
1299 Specific for EMX port. Gives the directory part of the location for
1302 =head2 C<TMP> or C<TEMP>
1304 Specific for EMX port. Used as storage place for temporary files, most
1305 notably C<-e> scripts.
1309 Here we list major changes which could make you by surprise.
1313 C<setpriority> and C<getpriority> are not compatible with earlier
1314 ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1316 =head2 DLL name mangling
1318 With the release 5.003_01 the dynamically loadable libraries
1319 should be rebuilt. In particular, DLLs are now created with the names
1320 which contain a checksum, thus allowing workaround for OS/2 scheme of
1325 As of release 5.003_01 perl is linked to multithreaded CRT
1326 DLL. Perl itself is not multithread-safe, as is not perl
1327 malloc(). However, extensions may use multiple thread on their own
1330 Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
1332 =head2 Calls to external programs
1334 Due to a popular demand the perl external program calling has been
1335 changed wrt Andreas Kaiser's port. I<If> perl needs to call an
1336 external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1337 whatever is the override, see L<"PERL_SH_DIR">.
1339 Thus means that you need to get some copy of a F<sh.exe> as well (I
1340 use one from pdksh). The drive F: above is set up automatically during
1341 the build to a correct value on the builder machine, but is
1342 overridable at runtime,
1344 B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1345 one non-overridable shell per platform. The obvious choices for OS/2
1346 are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
1347 with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
1348 100% compatibility with the scripts coming from *nix. As an added benefit
1349 this works as well under DOS if you use DOS-enabled port of pdksh
1350 (see L<"Prerequisites">).
1352 B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
1353 via fork()/exec(), and there is I<no> functioning exec() on
1354 OS/2. exec() is emulated by EMX by asyncroneous call while the caller
1355 waits for child completion (to pretend that the C<pid> did not change). This
1356 means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1357 which may lead to some resources taken from the system (even if we do
1358 not count extra work needed for fork()ing).
1360 Note that this a lesser issue now when we do not spawn F<sh.exe>
1361 unless needed (metachars found).
1363 One can always start F<cmd.exe> explicitly via
1365 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1367 If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
1368 scripts, the long-term solution proposed on p5-p is to have a directive
1372 which will override system(), exec(), C<``>, and
1373 C<open(,'...|')>. With current perl you may override only system(),
1374 readpipe() - the explicit version of C<``>, and maybe exec(). The code
1375 will substitute the one-argument call to system() by
1376 C<CORE::system('cmd.exe', '/c', shift)>.
1378 If you have some working code for C<OS2::Cmd>, please send it to me,
1379 I will include it into distribution. I have no need for such a module, so
1382 =head2 Memory allocation
1384 Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
1385 for speed, but perl is not, since its malloc is lightning-fast.
1386 Unfortunately, it is also quite frivolous with memory usage as well.
1388 Since kitchen-top machines are usually low on memory, perl is compiled with
1389 all the possible memory-saving options. This probably makes perl's
1390 malloc() as greedy with memory as the neighbor's malloc(), but still
1391 much quickier. Note that this is true only for a "typical" usage,
1392 it is possible that the perl malloc will be worse for some very special usage.
1394 Combination of perl's malloc() and rigid DLL name resolution creates
1395 a special problem with library functions which expect their return value to
1396 be free()d by system's free(). To facilitate extensions which need to call
1397 such functions, system memory-allocation functions are still available with
1398 the prefix C<emx_> added. (Currently only DLL perl has this, it should
1399 propagate to F<perl_.exe> shortly.)
1405 I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
1406 into my ftp directory, mirrored on CPAN. I made
1407 some minor changes needed to compile them by standard tools. I cannot
1408 test UPM and FTP, so I will appreciate your feedback. Other extensions
1409 there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1410 files - and maybe some other extensions at the time you read it.
1412 Note that OS2 perl defines 2 pseudo-extension functions
1413 OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1414 L<Prebuilt methods>).
1416 The -R switch of older perl is deprecated. If you need to call a REXX code
1417 which needs access to variables, include the call into a REXX compartment
1419 REXX_call {...block...};
1421 Two new functions are supported by REXX code,
1423 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1425 If you have some other extensions you want to share, send the code to
1426 me. At least two are available: tied access to EA's, and tied access
1427 to system databases.
1431 Ilya Zakharevich, ilya@math.ohio-state.edu