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
34 Note that if you have F<lynx.exe> installed, you can follow WWW links
35 from this document in F<.INF> format. If you have EMX docs installed
36 correctly, you can follow library links (you need to have C<view emxbook>
37 working by setting C<EMXBOOK> environment variable as it is described
44 perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.
52 - Starting Perl programs under OS/2 (and DOS and...)
53 - Starting OS/2 (and DOS) programs under Perl
54 Frequently asked questions
55 - I cannot run external programs
56 - I cannot embed perl into my program, or use perl.dll from my program.
57 - `` and pipe-open do not work under DOS.
58 - Cannot start find.exe "pattern" file
60 - Automatic binary installation
61 - Manual binary installation
63 Accessing documentation
74 - Application of the patches
78 - Installing the built perl
81 - Some / became \ in pdksh.
82 - 'errno' - unresolved external
84 - Some problem (forget which ;-)
85 - Library ... not found
87 Specific (mis)features of EMX port
88 - setpriority, getpriority
90 - extproc on the first line
101 - Why dynamic linking?
113 - Calls to external programs
122 The target is to make OS/2 the best supported platform for
123 using/building/developing Perl and I<Perl applications>, as well as
124 make Perl the best language to use under OS/2. The secondary target is
125 to try to make this work under DOS and Win* as well (but not B<too> hard).
127 The current state is quite close to this target. Known limitations:
133 Some *nix programs use fork() a lot, but currently fork() is not
134 supported after I<use>ing dynamically loaded extensions.
138 You need a separate perl executable F<perl__.exe> (see L<perl__.exe>)
139 to use PM code in your application (like the forthcoming Perl/Tk).
143 There is no simple way to access WPS objects. The only way I know
144 is via C<OS2::REXX> extension (see L<OS2::REXX>), and we do not have access to
145 convenience methods of Object-REXX. (Is it possible at all? I know
146 of no Object-REXX API.)
150 Please keep this list up-to-date by informing me about other items.
154 Since OS/2 port of perl uses a remarkable EMX environment, it can
155 run (and build extensions, and - possibly - be build itself) under any
156 environment which can run EMX. The current list is DOS,
157 DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors,
158 only one works, see L<"perl_.exe">.
160 Note that not all features of Perl are available under these
161 environments. This depends on the features the I<extender> - most
162 probably RSX - decided to implement.
164 Cf. L<Prerequisites>.
172 EMX runtime is required (may be substituted by RSX). Note that
173 it is possible to make F<perl_.exe> to run under DOS without any
174 external support by binding F<emx.exe>/F<rsx.exe> to it, see L<emxbind>. Note
175 that under DOS for best results one should use RSX runtime, which
176 has much more functions working (like C<fork>, C<popen> and so on). In
177 fact RSX is required if there is no VCPI present. Note the
180 Only the latest runtime is supported, currently C<0.9c>. Perl may run
181 under earlier versions of EMX, but this is not tested.
183 One can get different parts of EMX from, say
185 ftp://ftp.cdrom.com/pub/os2/emx09c/
186 ftp://hobbes.nmsu.edu/os2/unix/emx09c/
188 The runtime component should have the name F<emxrt.zip>.
190 B<NOTE>. It is enough to have F<emx.exe>/F<rsx.exe> on your path. One
191 does not need to specify them explicitly (though this
199 To run Perl on DPMI platforms one needs RSX runtime. This is
200 needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see
201 L<"Other OSes">). RSX would not work with VCPI
202 only, as EMX would, it requires DMPI.
204 Having RSX and the latest F<sh.exe> one gets a fully functional
205 B<*nix>-ish environment under DOS, say, C<fork>, C<``> and
206 pipe-C<open> work. In fact, MakeMaker works (for static build), so one
207 can have Perl development environment under DOS.
209 One can get RSX from, say
211 ftp://ftp.cdrom.com/pub/os2/emx09c/contrib
212 ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc
213 ftp://ftp.leo.org/pub/comp/os/os2/leo/devtools/emx+gcc/contrib
215 Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
217 The latest F<sh.exe> with DOS hooks is available at
219 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
223 Perl does not care about file systems, but to install the whole perl
224 library intact one needs a file system which supports long file names.
226 Note that if you do not plan to build the perl itself, it may be
227 possible to fool EMX to truncate file names. This is not supported,
228 read EMX docs to see how to do it.
232 To start external programs with complicated command lines (like with
233 pipes in between, and/or quoting of arguments), Perl uses an external
234 shell. With EMX port such shell should be named <sh.exe>, and located
235 either in the wired-in-during-compile locations (usually F<F:/bin>),
236 or in configurable location (see L<"PERL_SH_DIR">).
238 For best results use EMX pdksh. The soon-to-be-available standard
239 binary (5.2.12?) runs under DOS (with L<RSX>) as well, meanwhile use
242 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
246 =head2 Starting Perl programs under OS/2 (and DOS and...)
248 Start your Perl program F<foo.pl> with arguments C<arg1 arg2 arg3> the
249 same way as on any other platform, by
251 perl foo.pl arg1 arg2 arg3
253 If you want to specify perl options C<-my_opts> to the perl itself (as
254 opposed to to your program), use
256 perl -my_opts foo.pl arg1 arg2 arg3
258 Alternately, if you use OS/2-ish shell, like CMD or 4os2, put
259 the following at the start of your perl script:
261 extproc perl -S -my_opts
263 rename your program to F<foo.cmd>, and start it by typing
267 Note that because of stupid OS/2 limitations the full path of the perl
268 script is not available when you use C<extproc>, thus you are forced to
269 use C<-S> perl switch, and your script should be on path. As a plus
270 side, if you know a full path to your script, you may still start it
273 perl ../../blah/foo.cmd arg1 arg2 arg3
275 (note that the argument C<-my_opts> is taken care of by the C<extproc> line
276 in your script, see L<C<extproc> on the first line>).
278 To understand what the above I<magic> does, read perl docs about C<-S>
279 switch - see L<perlrun>, and cmdref about C<extproc>:
286 or whatever method you prefer.
288 There are also endless possibilities to use I<executable extensions> of
289 4os2, I<associations> of WPS and so on... However, if you use
290 *nixish shell (like F<sh.exe> supplied in the binary distribution),
291 you need to follow the syntax specified in L<perlrun/"Switches">.
293 =head2 Starting OS/2 (and DOS) programs under Perl
295 This is what system() (see L<perlfunc/system>), C<``> (see
296 L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
297 are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
300 Note however that to use some of these operators you need to have a
301 sh-syntax shell installed (see L<"Pdksh">,
302 L<"Frequently asked questions">), and perl should be able to find it
303 (see L<"PERL_SH_DIR">).
305 The only cases when the shell is not used is the multi-argument
306 system() (see L<perlfunc/system>)/exec() (see L<perlfunc/exec>), and
307 one-argument version thereof without redirection and shell
310 =head1 Frequently asked questions
312 =head2 I cannot run external programs
318 Did you run your programs with C<-w> switch? See
319 L<Starting OS/2 (and DOS) programs under Perl>.
323 Do you try to run I<internal> shell commands, like C<`copy a b`>
324 (internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
325 need to specify your shell explicitly, like C<`cmd /c copy a b`>,
326 since Perl cannot deduce which commands are internal to your shell.
330 =head2 I cannot embed perl into my program, or use F<perl.dll> from my
335 =item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
337 If not, you need to build a stand-alone DLL for perl. Contact me, I
338 did it once. Sockets would not work, as a lot of other stuff.
340 =item Did you use L<ExtUtils::Embed>?
342 I had reports it does not work. Somebody would need to fix it.
346 =head2 C<``> and pipe-C<open> do not work under DOS.
348 This may a variant of just L<"I cannot run external programs">, or a
349 deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
350 for these commands to work, and you may need a port of F<sh.exe> which
351 understands command arguments. One of such ports is listed in
352 L<"Prerequisites"> under RSX. Do not forget to set variable
353 C<L<"PERL_SH_DIR">> as well.
355 DPMI is required for RSX.
357 =head2 Cannot start C<find.exe "pattern" file>
361 system 'cmd', '/c', 'find "pattern" file';
362 `cmd /c 'find "pattern" file'`
364 This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
365 C<perl.exe>, but this is a price to pay if you want to use
366 non-conforming program. In fact F<find.exe> cannot be started at all
367 using C library API only. Otherwise the following command-lines were
375 =head2 Automatic binary installation
377 The most convenient way of installing perl is via perl installer
378 F<install.exe>. Just follow the instructions, and 99% of the
379 installation blues would go away.
381 Note however, that you need to have F<unzip.exe> on your path, and
382 EMX environment I<running>. The latter means that if you just
383 installed EMX, and made all the needed changes to F<Config.sys>,
384 you may need to reboot in between. Check EMX runtime by running
388 A folder is created on your desktop which contains some useful
391 B<Things not taken care of by automatic binary installation:>
395 =item C<PERL_BADLANG>
397 may be needed if you change your codepage I<after> perl installation,
398 and the new value is not supported by EMX. See L<"PERL_BADLANG">.
400 =item C<PERL_BADFREE>
402 see L<"PERL_BADFREE">.
406 This file resides somewhere deep in the location you installed your
407 perl library, find it out by
409 perl -MConfig -le "print $INC{'Config.pm'}"
411 While most important values in this file I<are> updated by the binary
412 installer, some of them may need to be hand-edited. I know no such
413 data, please keep me informed if you find one.
417 B<NOTE>. Because of a typo the binary installer of 5.00305
418 would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
419 remove this variable and put C<L<PERL_SH_DIR>> instead.
421 =head2 Manual binary installation
423 As of version 5.00305, OS/2 perl binary distribution comes split
424 into 11 components. Unfortunately, to enable configurable binary
425 installation, the file paths in the zip files are not absolute, but
426 relative to some directory.
428 Note that the extraction with the stored paths is still necessary
429 (default with unzip, specify C<-d> to pkunzip). However, you
430 need to know where to extract the files. You need also to manually
431 change entries in F<Config.sys> to reflect where did you put the
432 files. Note that if you have some primitive unzipper (like
433 pkunzip), you may get a lot of warnings/errors during
434 unzipping. Upgrade to C<(w)unzip>.
436 Below is the sample of what to do to reproduce the configuration on my
441 =item Perl VIO and PM executables (dynamically linked)
443 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
444 unzip perl_exc.zip *.dll -d f:/emx.add/dll
446 (have the directories with C<*.exe> on PATH, and C<*.dll> on
449 =item Perl_ VIO executable (statically linked)
451 unzip perl_aou.zip -d f:/emx.add/bin
453 (have the directory on PATH);
455 =item Executables for Perl utilities
457 unzip perl_utl.zip -d f:/emx.add/bin
459 (have the directory on PATH);
461 =item Main Perl library
463 unzip perl_mlb.zip -d f:/perllib/lib
465 If this directory is preserved, you do not need to change
466 anything. However, for perl to find it if it is changed, you need to
467 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
469 =item Additional Perl modules
471 unzip perl_ste.zip -d f:/perllib/lib/site_perl
473 If you do not change this directory, do nothing. Otherwise put this
474 directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
475 variable. Do not use C<PERL5LIB> unless you have it set already. See
476 L<perl/"ENVIRONMENT">.
478 =item Tools to compile Perl modules
480 unzip perl_blb.zip -d f:/perllib/lib
482 If this directory is preserved, you do not need to change
483 anything. However, for perl to find it if it is changed, you need to
484 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
486 =item Manpages for Perl and utilities
488 unzip perl_man.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 Manpages for Perl modules
495 unzip perl_mam.zip -d f:/perllib/man
497 This directory should better be on C<MANPATH>. You need to have a
498 working man to access these files.
500 =item Source for Perl documentation
502 unzip perl_pod.zip -d f:/perllib/lib
504 This is used by by C<perldoc> program (see L<perldoc>), and may be used to
505 generate HTML documentation usable by WWW browsers, and
506 documentation in zillions of other formats: C<info>, C<LaTeX>,
507 C<Acrobat>, C<FrameMaker> and so on.
509 =item Perl manual in F<.INF> format
511 unzip perl_inf.zip -d d:/os2/book
513 This directory should better be on C<BOOKSHELF>.
517 unzip perl_sh.zip -d f:/bin
519 This is used by perl to run external commands which explicitly
520 require shell, like the commands using I<redirection> and I<shell
521 metacharacters>. It is also used instead of explicit F</bin/sh>.
523 Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
526 B<Note.> It may be possible to use some other sh-compatible shell
531 After you installed the components you needed and updated the
532 F<Config.sys> correspondingly, you need to hand-edit
533 F<Config.pm>. This file resides somewhere deep in the location you
534 installed your perl library, find it out by
536 perl -MConfig -le "print $INC{'Config.pm'}"
538 You need to correct all the entries which look like file paths (they
539 currently start with C<f:/>).
543 The automatic and manual perl installation leave precompiled paths
544 inside perl executables. While these paths are overwriteable (see
545 L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
546 binary editing of paths inside the executables/DLLs.
548 =head1 Accessing documentation
550 Depending on how you built/installed perl you may have (otherwise
551 identical) Perl documentation in the following formats:
553 =head2 OS/2 F<.INF> file
555 Most probably the most convenient form. Under OS/2 view it as
560 view perl ExtUtils::MakeMaker
562 (currently the last two may hit a wrong location, but this may improve
563 soon). Under Win* see L<"SYNOPSIS">.
565 If you want to build the docs yourself, and have I<OS/2 toolkit>, run
569 in F</perllib/lib/pod> directory, then
573 (Expect a lot of errors during the both steps.) Now move it on your
578 If you have perl documentation in the source form, perl utilities
579 installed, and GNU groff installed, you may use
583 perldoc ExtUtils::MakeMaker
585 to access the perl documentation in the text form (note that you may get
586 better results using perl manpages).
588 Alternately, try running pod2text on F<.pod> files.
592 If you have man installed on your system, and you installed perl
593 manpages, use something like this:
597 man ExtUtils.MakeMaker
599 to access documentation for different components of Perl. Start with
603 Note that dot (F<.>) is used as a package separator for documentation
604 for packages, and as usual, sometimes you need to give the section - C<3>
605 above - to avoid shadowing by the I<less(1) manpage>.
607 Make sure that the directory B<above> the directory with manpages is
608 on our C<MANPATH>, like this
610 set MANPATH=c:/man;f:/perllib/man
614 If you have some WWW browser available, installed the Perl
615 documentation in the source form, and Perl utilities, you can build
616 HTML docs. Cd to directory with F<.pod> files, and do like this
618 cd f:/perllib/lib/pod
621 After this you can direct your browser the file F<perl.html> in this
622 directory, and go ahead with reading docs, like this:
624 explore file:///f:/perllib/lib/pod/perl.html
626 Alternatively you may be able to get these docs prebuilt from CPAN.
628 =head2 GNU C<info> files
630 Users of Emacs would appreciate it very much, especially with
631 C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
632 or, alternately, prebuilt info pages.
636 for C<Acrobat> are available on CPAN (for slightly old version of
641 can be constructed using C<pod2latex>.
645 Here we discuss how to build Perl under OS/2. There is an alternative
646 (but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
650 You need to have the latest EMX development environment, the full
651 GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
652 earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
658 ). You need the latest version of F<pdksh> installed as F<sh.exe>.
660 Possible locations to get this from are
662 ftp://hobbes.nmsu.edu/os2/unix/
663 ftp://ftp.cdrom.com/pub/os2/unix/
664 ftp://ftp.cdrom.com/pub/os2/dev32/
665 ftp://ftp.cdrom.com/pub/os2/emx09c/
668 Make sure that no copies or perl are currently running. Later steps
669 of the build may fail since an older version of perl.dll loaded into
672 Also make sure that you have F</tmp> directory on the current drive,
673 and F<.> directory in your C<LIBPATH>. One may try to correct the
678 if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
680 Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
681 script in F</emx/lib> directory.
683 Check that you have link386 installed. It comes standard with OS/2,
684 but may be not installed due to customization. If typing
688 shows you do not have it, do I<Selective install>, and choose C<Link
689 object modules> in I<Optional system utilities/More>. If you get into
690 link386, press C<Ctrl-C>.
692 =head2 Getting perl source
694 You need to fetch the latest perl source (including developers
695 releases). With some probability it is located in
697 http://www.perl.com/CPAN/src/5.0
698 http://www.perl.com/CPAN/src/5.0/unsupported
700 If not, you may need to dig in the indices to find it in the directory
701 of the current maintainer.
703 Quick cycle of developers release may break the OS/2 build time to
706 http://www.perl.com/CPAN/ports/os2/ilyaz/
708 may indicate the latest release which was publicly released by the
709 maintainer. Note that the release may include some additional patches
710 to apply to the current source of perl.
714 tar vzxf perl5.00409.tar.gz
716 You may see a message about errors while extracting F<Configure>. This is
717 because there is a conflict with a similarly-named file F<configure>.
719 Change to the directory of extraction.
721 =head2 Application of the patches
723 You need to apply the patches in F<./os2/diff.*> and
724 F<./os2/POSIX.mkfifo> like this:
726 gnupatch -p0 < os2\POSIX.mkfifo
727 gnupatch -p0 < os2\diff.configure
729 You may also need to apply the patches supplied with the binary
730 distribution of perl.
732 Note also that the F<db.lib> and F<db.a> from the EMX distribution
733 are not suitable for multi-threaded compile (note that currently perl
734 is not multithread-safe, but is compiled as multithreaded for
735 compatibility with XFree86-OS/2). Get a corrected one from
737 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
741 You may look into the file F<./hints/os2.sh> and correct anything
742 wrong you find there. I do not expect it is needed anywhere.
746 sh Configure -des -D prefix=f:/perllib
748 C<prefix> means: where to install the resulting perl library. Giving
749 correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
750 see L<"PERLLIB_PREFIX">.
752 I<Ignore the message about missing C<ln>, and about C<-c> option to
753 tr>. In fact if you can trace where the latter spurious warning
754 comes from, please inform me.
760 At some moment the built may die, reporting a I<version mismatch> or
761 I<unable to run F<perl>>. This means that most of the build has been
762 finished, and it is the time to move the constructed F<perl.dll> to
763 some I<absolute> location in LIBPATH. After this is done the build
764 should finish without a lot of fuss. I<One can avoid the interruption
765 if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
766 probably this is not needed anymore, since F<miniperl.exe> is linked
769 Warnings which are safe to ignore: I<mkfifo() redefined> inside
778 Some tests (4..6) should fail. Some perl invocations should end in a
779 segfault (system error C<SYS3175>). To get finer error reports,
784 The report you get may look like
786 Failed Test Status Wstat Total Fail Failed List of failed
787 ---------------------------------------------------------------
788 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
789 lib/io_pipe.t 3 768 6 ?? % ??
790 lib/io_sock.t 3 768 5 ?? % ??
791 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
792 Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
794 Note that using `make test' target two more tests may fail: C<op/exec:1>
795 because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
796 that the buffers are not flushed on C<_exit> (this is a bug in the test
797 which assumes that tty output is buffered).
799 I submitted a patch to EMX which makes it possible to fork() with EMX
800 dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
801 that soon the number of failing tests may decrease yet more.
803 However, the test F<lib/io_udp.t> is disabled, since it never terminates, I
804 do not know why. Comments/fixes welcome.
806 The reasons for failed tests are:
812 Checks I<file system> operations. Tests:
818 Check C<link()> and C<inode count> - nonesuch under OS/2.
822 Checks C<atime> and C<mtime> of C<stat()> - I could not understand this test.
826 Checks C<truncate()> on a filehandle just opened for write - I do not
827 know why this should or should not work.
831 =item F<lib/io_pipe.t>
833 Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
834 dynamic extension loaded - unsupported now.
836 =item F<lib/io_sock.t>
838 Checks C<IO::Socket> module. Some feature of EMX - test fork()s
839 with dynamic extension loaded - unsupported now.
843 Checks C<stat()>. Tests:
849 Checks C<inode count> - nonesuch under OS/2.
853 Checks C<mtime> and C<ctime> of C<stat()> - I could not understand this test.
857 Checks C<-x> - determined by the file extension only under OS/2.
865 Checks C<-t> of F</dev/null>. Should not fail!
871 In addition to errors, you should get a lot of warnings.
875 =item A lot of `bad free'
877 in databases related to Berkeley DB. This is a confirmed bug of
878 DB. You may disable this warnings, see L<"PERL_BADFREE">.
880 =item Process terminated by SIGTERM/SIGINT
882 This is a standard message issued by OS/2 applications. *nix
883 applications die in silence. It is considered a feature. One can
884 easily disable this by appropriate sighandlers.
886 However the test engine bleeds these message to screen in unexpected
887 moments. Two messages of this kind I<should> be present during
890 =item F<*/sh.exe>: ln: not found
892 =item C<ls>: /dev: No such file or directory
894 The last two should be self-explanatory. The test suite discovers that
895 the system it runs on is not I<that much> *nixish.
899 A lot of `bad free'... in databases, bug in DB confirmed on other
900 platforms. You may disable it by setting PERL_BADFREE environment variable
903 =head2 Installing the built perl
909 It would put the generated files into needed locations. Manually put
910 F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
911 PATH, F<perl.dll> to a location on your LIBPATH.
915 make cmdscripts INSTALLCMDDIR=d:/ir/on/path
917 to convert perl utilities to F<.cmd> files and put them on
918 PATH. You need to put F<.EXE>-utilities on path manually. They are
919 installed in C<$prefix/bin>, here C<$prefix> is what you gave to
920 F<Configure>, see L<Making>.
922 =head2 C<a.out>-style build
924 Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
933 Manually put F<perl_.exe> to a location on your PATH.
935 Since C<perl_> has the extensions prebuilt, it does not suffer from
936 the I<dynamic extensions + fork()> syndrome, thus the failing tests
939 Failed Test Status Wstat Total Fail Failed List of failed
940 ---------------------------------------------------------------
941 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
942 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
943 Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
945 B<Note.> The build process for C<perl_> I<does not know> about all the
946 dependencies, so you should make sure that anything is up-to-date,
955 =head2 Some C</> became C<\> in pdksh.
957 You have a very old pdksh. See L<Prerequisites>.
959 =head2 C<'errno'> - unresolved external
961 You do not have MT-safe F<db.lib>. See L<Prerequisites>.
963 =head2 Problems with tr
965 reported with very old version of tr.
967 =head2 Some problem (forget which ;-)
969 You have an older version of F<perl.dll> on your LIBPATH, which
970 broke the build of extensions.
972 =head2 Library ... not found
974 You did not run C<omflibs>. See L<Prerequisites>.
976 =head2 Segfault in make
978 You use an old version of GNU make. See L<Prerequisites>.
980 =head1 Specific (mis)features of OS/2 port
982 =head2 C<setpriority>, C<getpriority>
984 Note that these functions are compatible with *nix, not with the older
985 ports of '94 - 95. The priorities are absolute, go from 32 to -95,
986 lower is quicker. 0 is the default priority.
990 Multi-argument form of C<system()> allows an additional numeric
991 argument. The meaning of this argument is described in
994 =head2 C<extproc> on the first line
996 If the first chars of a script are C<"extproc ">, this line is treated
997 as C<#!>-line, thus all the switches on this line are processed (twice
998 if script was started via cmd.exe).
1000 =head2 Additional modules:
1002 L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. This
1003 modules provide access to additional numeric argument for C<system>,
1004 to DLLs having functions with REXX signature and to REXX runtime, to
1005 OS/2 databases in the F<.INI> format, and to Extended Attributes.
1007 Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
1008 C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
1010 =head2 Prebuilt methods:
1014 =item C<File::Copy::syscopy>
1016 used by C<File::Copy::copy>, see L<File::Copy>.
1018 =item C<DynaLoader::mod2fname>
1020 used by C<DynaLoader> for DLL name mangling.
1022 =item C<Cwd::current_drive()>
1026 =item C<Cwd::sys_chdir(name)>
1028 leaves drive as it is.
1030 =item C<Cwd::change_drive(name)>
1033 =item C<Cwd::sys_is_absolute(name)>
1035 means has drive letter and is_rooted.
1037 =item C<Cwd::sys_is_rooted(name)>
1039 means has leading C<[/\\]> (maybe after a drive-letter:).
1041 =item C<Cwd::sys_is_relative(name)>
1043 means changes with current dir.
1045 =item C<Cwd::sys_cwd(name)>
1047 Interface to cwd from EMX. Used by C<Cwd::cwd>.
1049 =item C<Cwd::sys_abspath(name, dir)>
1051 Really really odious function to implement. Returns absolute name of
1052 file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1055 =item C<Cwd::extLibpath([type])
1057 Get current value of extended library search path. If C<type> is
1058 present and I<true>, works with END_LIBPATH, otherwise with
1061 =item C<Cwd::extLibpath_set( path [, type ] )>
1063 Set current value of extended library search path. If C<type> is
1064 present and I<true>, works with END_LIBPATH, otherwise with
1069 (Note that some of these may be moved to different libraries -
1079 Since L<flock(3)> is present in EMX, but is not functional, the same is
1080 true for perl. Here is the list of things which may be "broken" on
1081 EMX (from EMX docs):
1087 The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not
1092 L<sock_init(3)> is not required and not implemented.
1096 L<flock(3)> is not yet implemented (dummy function).
1100 L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1108 waitpid() is not implemented for negative values of PID.
1112 Note that C<kill -9> does not work with the current version of EMX.
1116 Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
1117 of F<sh.exe> plague perl as well.
1119 In particular, uppercase letters do not work in C<[...]>-patterns with
1124 =head2 Modifications
1126 Perl modifies some standard C library calls in the following ways:
1132 C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
1136 is created using C<TMP> or C<TEMP> environment variable, via
1141 If the current directory is not writable, file is created using modified
1142 C<tmpnam>, so there may be a race condition.
1146 a dummy implementation.
1150 C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1156 Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
1157 same basket (though EMX environment tries hard to overcome this
1158 limitations, so the situation may somehow improve). There are 4
1159 executables for Perl provided by the distribution:
1163 The main workhorse. This is a chimera executable: it is compiled as an
1164 C<a.out>-style executable, but is linked with C<omf>-style dynamic
1165 library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1168 It can load perl dynamic extensions, and it can fork(). Unfortunately,
1169 with the current version of EMX it cannot fork() with dynamic
1170 extensions loaded (may be fixed by patches to EMX).
1172 B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1176 This is a statically linked C<a.out>-style executable. It can fork(),
1177 but cannot load dynamic Perl extensions. The supplied executable has a
1178 lot of extensions prebuilt, thus there are situations when it can
1179 perform tasks not possible using F<perl.exe>, like fork()ing when
1180 having some standard extension loaded. This executable is a VIO
1183 B<Note.> A better behaviour could be obtained from C<perl.exe> if it
1184 were statically linked with standard I<Perl extensions>, but
1185 dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
1186 be able to fork() with standard extensions, I<and> would be able to
1187 dynamically load arbitrary extensions. Some changes to Makefiles and
1188 hint files should be necessary to achieve this.
1190 I<This is also the only executable with does not require OS/2.> The
1191 friends locked into C<M$> world would appreciate the fact that this
1192 executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
1193 appropriate extender. See L<"Other OSes">.
1195 =head2 F<perl__.exe>
1197 This is the same executable as F<perl___.exe>, but it is a PM
1200 B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
1201 application are redirected to C<nul>. However, it is possible to see
1202 them if you start C<perl__.exe> from a PM program which emulates a
1203 console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
1204 possible> to use Perl debugger (see L<perldebug>) to debug your PM
1207 This flavor is required if you load extensions which use PM, like
1208 the forthcoming C<Perl/Tk>.
1210 =head2 F<perl___.exe>
1212 This is an C<omf>-style executable which is dynamically linked to
1213 F<perl.dll> and CRT DLL. I know no advantages of this executable
1214 over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1215 that the build process is not so convoluted as with C<perl.exe>.
1217 It is a VIO application.
1219 =head2 Why strange names?
1221 Since Perl processes the C<#!>-line (cf.
1222 L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1223 L<perldiag/"Not a perl script">,
1224 L<perldiag/"No Perl script found in input">), it should know when a
1225 program I<is a Perl>. There is some naming convention which allows
1226 Perl to distinguish correct lines from wrong ones. The above names are
1227 almost the only names allowed by this convention which do not contain
1228 digits (which have absolutely different semantics).
1230 =head2 Why dynamic linking?
1232 Well, having several executables dynamically linked to the same huge
1233 library has its advantages, but this would not substantiate the
1234 additional work to make it compile. The reason is stupid-but-quick
1235 "hard" dynamic linking used by OS/2.
1237 The address tables of DLLs are patched only once, when they are
1238 loaded. The addresses of entry points into DLLs are guaranteed to be
1239 the same for all programs which use the same DLL, which reduces the
1240 amount of runtime patching - once DLL is loaded, its code is
1243 While this allows some performance advantages, this makes life
1244 terrible for developers, since the above scheme makes it impossible
1245 for a DLL to be resolved to a symbol in the .EXE file, since this
1246 would need a DLL to have different relocations tables for the
1247 executables which use it.
1249 However, a Perl extension is forced to use some symbols from the perl
1250 executable, say to know how to find the arguments provided on the perl
1251 internal evaluation stack. The solution is that the main code of
1252 interpreter should be contained in a DLL, and the F<.EXE> file just loads
1253 this DLL into memory and supplies command-arguments.
1255 This I<greatly> increases the load time for the application (as well as
1256 the number of problems during compilation). Since interpreter is in a DLL,
1257 the CRT is basically forced to reside in a DLL as well (otherwise
1258 extensions would not be able to use CRT).
1260 =head2 Why chimera build?
1262 Current EMX environment does not allow DLLs compiled using Unixish
1263 C<a.out> format to export symbols for data. This forces C<omf>-style
1264 compile of F<perl.dll>.
1266 Current EMX environment does not allow F<.EXE> files compiled in
1267 C<omf> format to fork(). fork() is needed for exactly three Perl
1272 =item explicit fork()
1280 opening pipes to itself.
1284 While these operations are not questions of life and death, a lot of
1285 useful scripts use them. This forces C<a.out>-style compile of
1291 Here we list environment variables with are either OS/2- and DOS- and
1292 Win*-specific, or are more important under OS/2 than under other OSes.
1294 =head2 C<PERLLIB_PREFIX>
1296 Specific for EMX port. Should have the form
1304 If the beginning of some prebuilt path matches F<path1>, it is
1305 substituted with F<path2>.
1307 Should be used if the perl library is moved from the default
1308 location in preference to C<PERL(5)LIB>, since this would not leave wrong
1311 =head2 C<PERL_BADLANG>
1313 If 1, perl ignores setlocale() failing. May be useful with some
1316 =head2 C<PERL_BADFREE>
1318 If 1, perl would not warn of in case of unwarranted free(). May be
1319 useful in conjunction with the module DB_File, since Berkeley DB
1320 memory handling code is buggy.
1322 =head2 C<PERL_SH_DIR>
1324 Specific for EMX port. Gives the directory part of the location for
1327 =head2 C<TMP> or C<TEMP>
1329 Specific for EMX port. Used as storage place for temporary files, most
1330 notably C<-e> scripts.
1334 Here we list major changes which could make you by surprise.
1338 C<setpriority> and C<getpriority> are not compatible with earlier
1339 ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1341 =head2 DLL name mangling
1343 With the release 5.003_01 the dynamically loadable libraries
1344 should be rebuilt. In particular, DLLs are now created with the names
1345 which contain a checksum, thus allowing workaround for OS/2 scheme of
1350 As of release 5.003_01 perl is linked to multithreaded CRT
1351 DLL. Perl itself is not multithread-safe, as is not perl
1352 malloc(). However, extensions may use multiple thread on their own
1355 Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
1357 =head2 Calls to external programs
1359 Due to a popular demand the perl external program calling has been
1360 changed wrt Andreas Kaiser's port. I<If> perl needs to call an
1361 external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1362 whatever is the override, see L<"PERL_SH_DIR">.
1364 Thus means that you need to get some copy of a F<sh.exe> as well (I
1365 use one from pdksh). The drive F: above is set up automatically during
1366 the build to a correct value on the builder machine, but is
1367 overridable at runtime,
1369 B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1370 one non-overridable shell per platform. The obvious choices for OS/2
1371 are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
1372 with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
1373 100% compatibility with the scripts coming from *nix. As an added benefit
1374 this works as well under DOS if you use DOS-enabled port of pdksh
1375 (see L<"Prerequisites">).
1377 B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
1378 via fork()/exec(), and there is I<no> functioning exec() on
1379 OS/2. exec() is emulated by EMX by asyncroneous call while the caller
1380 waits for child completion (to pretend that the C<pid> did not change). This
1381 means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1382 which may lead to some resources taken from the system (even if we do
1383 not count extra work needed for fork()ing).
1385 Note that this a lesser issue now when we do not spawn F<sh.exe>
1386 unless needed (metachars found).
1388 One can always start F<cmd.exe> explicitly via
1390 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1392 If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
1393 scripts, the long-term solution proposed on p5-p is to have a directive
1397 which will override system(), exec(), C<``>, and
1398 C<open(,'...|')>. With current perl you may override only system(),
1399 readpipe() - the explicit version of C<``>, and maybe exec(). The code
1400 will substitute the one-argument call to system() by
1401 C<CORE::system('cmd.exe', '/c', shift)>.
1403 If you have some working code for C<OS2::Cmd>, please send it to me,
1404 I will include it into distribution. I have no need for such a module, so
1407 =head2 Memory allocation
1409 Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
1410 for speed, but perl is not, since its malloc is lightning-fast.
1411 Unfortunately, it is also quite frivolous with memory usage as well.
1413 Since kitchen-top machines are usually low on memory, perl is compiled with
1414 all the possible memory-saving options. This probably makes perl's
1415 malloc() as greedy with memory as the neighbor's malloc(), but still
1416 much quickier. Note that this is true only for a "typical" usage,
1417 it is possible that the perl malloc will be worse for some very special usage.
1419 Combination of perl's malloc() and rigid DLL name resolution creates
1420 a special problem with library functions which expect their return value to
1421 be free()d by system's free(). To facilitate extensions which need to call
1422 such functions, system memory-allocation functions are still available with
1423 the prefix C<emx_> added. (Currently only DLL perl has this, it should
1424 propagate to F<perl_.exe> shortly.)
1430 I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
1431 into my ftp directory, mirrored on CPAN. I made
1432 some minor changes needed to compile them by standard tools. I cannot
1433 test UPM and FTP, so I will appreciate your feedback. Other extensions
1434 there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1435 files - and maybe some other extensions at the time you read it.
1437 Note that OS2 perl defines 2 pseudo-extension functions
1438 OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1439 L<Prebuilt methods>).
1441 The -R switch of older perl is deprecated. If you need to call a REXX code
1442 which needs access to variables, include the call into a REXX compartment
1444 REXX_call {...block...};
1446 Two new functions are supported by REXX code,
1448 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1450 If you have some other extensions you want to share, send the code to
1451 me. At least two are available: tied access to EA's, and tied access
1452 to system databases.
1456 Ilya Zakharevich, ilya@math.ohio-state.edu