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 Note that B<-S> switch enables a search with additional extensions
294 F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well.
296 =head2 Starting OS/2 (and DOS) programs under Perl
298 This is what system() (see L<perlfunc/system>), C<``> (see
299 L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
300 are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
303 Note however that to use some of these operators you need to have a
304 sh-syntax shell installed (see L<"Pdksh">,
305 L<"Frequently asked questions">), and perl should be able to find it
306 (see L<"PERL_SH_DIR">).
308 The cases when the shell is used are:
314 One-argument system() (see L<perlfunc/system>), exec() (see L<perlfunc/exec>)
315 with redirection or shell meta-characters;
319 Pipe-open (see L<perlfunc/open>) with the command which contains redirection
320 or shell meta-characters;
324 Backticks C<``> (see L<perlop/"I/O Operators">) with the command which contains
325 redirection or shell meta-characters;
329 If the executable called by system()/exec()/pipe-open()/C<``> is a script
330 with the "magic" C<#!> line or C<extproc> line which specifies shell;
334 If the executable called by system()/exec()/pipe-open()/C<``> is a script
335 without "magic" line, and C<$ENV{EXECSHELL}> is set to shell;
339 If the executable called by system()/exec()/pipe-open()/C<``> is not
344 For globbing (see L<perlfunc/glob>, L<perlop/"I/O Operators">).
348 For the sake of speed for a common case, in the above algorithms
349 backslashes in the command name are not considered as shell metacharacters.
351 Perl starts scripts which begin with cookies
352 C<extproc> or C<#!> directly, without an intervention of shell. Perl uses the
353 same algorithm to find the executable as F<pdksh>: if the path
354 on C<#!> line does not work, and contains C</>, then the executable
355 is searched in F<.> and on C<PATH>. To find arguments for these scripts
356 Perl uses a different algorithm than F<pdksh>: up to 3 arguments are
357 recognized, and trailing whitespace is stripped.
360 does not contain such a cooky, then to avoid calling F<sh.exe>, Perl uses
361 the same algorithm as F<pdksh>: if C<$ENV{EXECSHELL}> is set, the
362 script is given as the first argument to this command, if not set, then
363 C<$ENV{COMSPEC} /c> is used (or a hardwired guess if C<$ENV{COMSPEC}> is
366 If starting scripts directly, Perl will use exactly the same algorithm as for
367 the search of script given by B<-S> command-line option: it will look in
368 the current directory, then on components of C<$ENV{PATH}> using the
369 following order of appended extensions: no extension, F<.cmd>, F<.btm>,
372 Note that Perl will start to look for scripts only if OS/2 cannot start the
373 specified application, thus C<system 'blah'> will not look for a script if
374 there is an executable file F<blah.exe> I<anywhere> on C<PATH>.
376 Note also that executable files on OS/2 can have an arbitrary extension,
377 but F<.exe> will be automatically appended if no dot is present in the name.
378 The workaround as as simple as that: since F<blah.> and F<blah> denote the
379 same file, to start an executable residing in file F<n:/bin/blah> (no
380 extension) give an argument C<n:/bin/blah.> to system().
382 The last note is that currently it is not straightforward to start PM
383 programs from VIO (=text-mode) Perl process and visa versa. Either ensure
384 that shell will be used, as in C<system 'cmd /c epm'>, or start it using
385 optional arguments to system() documented in C<OS2::Process> module. This
386 is considered a bug and should be fixed soon.
389 =head1 Frequently asked questions
391 =head2 I cannot run external programs
397 Did you run your programs with C<-w> switch? See
398 L<Starting OS/2 (and DOS) programs under Perl>.
402 Do you try to run I<internal> shell commands, like C<`copy a b`>
403 (internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
404 need to specify your shell explicitly, like C<`cmd /c copy a b`>,
405 since Perl cannot deduce which commands are internal to your shell.
409 =head2 I cannot embed perl into my program, or use F<perl.dll> from my
414 =item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
416 If not, you need to build a stand-alone DLL for perl. Contact me, I
417 did it once. Sockets would not work, as a lot of other stuff.
419 =item Did you use L<ExtUtils::Embed>?
421 I had reports it does not work. Somebody would need to fix it.
425 =head2 C<``> and pipe-C<open> do not work under DOS.
427 This may a variant of just L<"I cannot run external programs">, or a
428 deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
429 for these commands to work, and you may need a port of F<sh.exe> which
430 understands command arguments. One of such ports is listed in
431 L<"Prerequisites"> under RSX. Do not forget to set variable
432 C<L<"PERL_SH_DIR">> as well.
434 DPMI is required for RSX.
436 =head2 Cannot start C<find.exe "pattern" file>
440 system 'cmd', '/c', 'find "pattern" file';
441 `cmd /c 'find "pattern" file'`
443 This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
444 C<perl.exe>, but this is a price to pay if you want to use
445 non-conforming program. In fact F<find.exe> cannot be started at all
446 using C library API only. Otherwise the following command-lines were
454 =head2 Automatic binary installation
456 The most convenient way of installing perl is via perl installer
457 F<install.exe>. Just follow the instructions, and 99% of the
458 installation blues would go away.
460 Note however, that you need to have F<unzip.exe> on your path, and
461 EMX environment I<running>. The latter means that if you just
462 installed EMX, and made all the needed changes to F<Config.sys>,
463 you may need to reboot in between. Check EMX runtime by running
467 A folder is created on your desktop which contains some useful
470 B<Things not taken care of by automatic binary installation:>
474 =item C<PERL_BADLANG>
476 may be needed if you change your codepage I<after> perl installation,
477 and the new value is not supported by EMX. See L<"PERL_BADLANG">.
479 =item C<PERL_BADFREE>
481 see L<"PERL_BADFREE">.
485 This file resides somewhere deep in the location you installed your
486 perl library, find it out by
488 perl -MConfig -le "print $INC{'Config.pm'}"
490 While most important values in this file I<are> updated by the binary
491 installer, some of them may need to be hand-edited. I know no such
492 data, please keep me informed if you find one.
496 B<NOTE>. Because of a typo the binary installer of 5.00305
497 would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
498 remove this variable and put C<L<PERL_SH_DIR>> instead.
500 =head2 Manual binary installation
502 As of version 5.00305, OS/2 perl binary distribution comes split
503 into 11 components. Unfortunately, to enable configurable binary
504 installation, the file paths in the zip files are not absolute, but
505 relative to some directory.
507 Note that the extraction with the stored paths is still necessary
508 (default with unzip, specify C<-d> to pkunzip). However, you
509 need to know where to extract the files. You need also to manually
510 change entries in F<Config.sys> to reflect where did you put the
511 files. Note that if you have some primitive unzipper (like
512 pkunzip), you may get a lot of warnings/errors during
513 unzipping. Upgrade to C<(w)unzip>.
515 Below is the sample of what to do to reproduce the configuration on my
520 =item Perl VIO and PM executables (dynamically linked)
522 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
523 unzip perl_exc.zip *.dll -d f:/emx.add/dll
525 (have the directories with C<*.exe> on PATH, and C<*.dll> on
528 =item Perl_ VIO executable (statically linked)
530 unzip perl_aou.zip -d f:/emx.add/bin
532 (have the directory on PATH);
534 =item Executables for Perl utilities
536 unzip perl_utl.zip -d f:/emx.add/bin
538 (have the directory on PATH);
540 =item Main Perl library
542 unzip perl_mlb.zip -d f:/perllib/lib
544 If this directory is preserved, you do not need to change
545 anything. However, for perl to find it if it is changed, you need to
546 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
548 =item Additional Perl modules
550 unzip perl_ste.zip -d f:/perllib/lib/site_perl
552 If you do not change this directory, do nothing. Otherwise put this
553 directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
554 variable. Do not use C<PERL5LIB> unless you have it set already. See
555 L<perl/"ENVIRONMENT">.
557 =item Tools to compile Perl modules
559 unzip perl_blb.zip -d f:/perllib/lib
561 If this directory is preserved, you do not need to change
562 anything. However, for perl to find it if it is changed, you need to
563 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
565 =item Manpages for Perl and utilities
567 unzip perl_man.zip -d f:/perllib/man
569 This directory should better be on C<MANPATH>. You need to have a
570 working man to access these files.
572 =item Manpages for Perl modules
574 unzip perl_mam.zip -d f:/perllib/man
576 This directory should better be on C<MANPATH>. You need to have a
577 working man to access these files.
579 =item Source for Perl documentation
581 unzip perl_pod.zip -d f:/perllib/lib
583 This is used by by C<perldoc> program (see L<perldoc>), and may be used to
584 generate HTML documentation usable by WWW browsers, and
585 documentation in zillions of other formats: C<info>, C<LaTeX>,
586 C<Acrobat>, C<FrameMaker> and so on.
588 =item Perl manual in F<.INF> format
590 unzip perl_inf.zip -d d:/os2/book
592 This directory should better be on C<BOOKSHELF>.
596 unzip perl_sh.zip -d f:/bin
598 This is used by perl to run external commands which explicitly
599 require shell, like the commands using I<redirection> and I<shell
600 metacharacters>. It is also used instead of explicit F</bin/sh>.
602 Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
605 B<Note.> It may be possible to use some other sh-compatible shell
610 After you installed the components you needed and updated the
611 F<Config.sys> correspondingly, you need to hand-edit
612 F<Config.pm>. This file resides somewhere deep in the location you
613 installed your perl library, find it out by
615 perl -MConfig -le "print $INC{'Config.pm'}"
617 You need to correct all the entries which look like file paths (they
618 currently start with C<f:/>).
622 The automatic and manual perl installation leave precompiled paths
623 inside perl executables. While these paths are overwriteable (see
624 L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
625 binary editing of paths inside the executables/DLLs.
627 =head1 Accessing documentation
629 Depending on how you built/installed perl you may have (otherwise
630 identical) Perl documentation in the following formats:
632 =head2 OS/2 F<.INF> file
634 Most probably the most convenient form. Under OS/2 view it as
639 view perl ExtUtils::MakeMaker
641 (currently the last two may hit a wrong location, but this may improve
642 soon). Under Win* see L<"SYNOPSIS">.
644 If you want to build the docs yourself, and have I<OS/2 toolkit>, run
648 in F</perllib/lib/pod> directory, then
652 (Expect a lot of errors during the both steps.) Now move it on your
657 If you have perl documentation in the source form, perl utilities
658 installed, and GNU groff installed, you may use
662 perldoc ExtUtils::MakeMaker
664 to access the perl documentation in the text form (note that you may get
665 better results using perl manpages).
667 Alternately, try running pod2text on F<.pod> files.
671 If you have man installed on your system, and you installed perl
672 manpages, use something like this:
676 man ExtUtils.MakeMaker
678 to access documentation for different components of Perl. Start with
682 Note that dot (F<.>) is used as a package separator for documentation
683 for packages, and as usual, sometimes you need to give the section - C<3>
684 above - to avoid shadowing by the I<less(1) manpage>.
686 Make sure that the directory B<above> the directory with manpages is
687 on our C<MANPATH>, like this
689 set MANPATH=c:/man;f:/perllib/man
693 If you have some WWW browser available, installed the Perl
694 documentation in the source form, and Perl utilities, you can build
695 HTML docs. Cd to directory with F<.pod> files, and do like this
697 cd f:/perllib/lib/pod
700 After this you can direct your browser the file F<perl.html> in this
701 directory, and go ahead with reading docs, like this:
703 explore file:///f:/perllib/lib/pod/perl.html
705 Alternatively you may be able to get these docs prebuilt from CPAN.
707 =head2 GNU C<info> files
709 Users of Emacs would appreciate it very much, especially with
710 C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
711 or, alternately, prebuilt info pages.
715 for C<Acrobat> are available on CPAN (for slightly old version of
720 can be constructed using C<pod2latex>.
724 Here we discuss how to build Perl under OS/2. There is an alternative
725 (but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
729 You need to have the latest EMX development environment, the full
730 GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
731 earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
737 ). You need the latest version of F<pdksh> installed as F<sh.exe>.
739 Check that you have B<BSD> libraries and headers installed, and -
740 optionally - Berkeley DB headers and libraries, and crypt.
742 Possible locations to get this from are
744 ftp://hobbes.nmsu.edu/os2/unix/
745 ftp://ftp.cdrom.com/pub/os2/unix/
746 ftp://ftp.cdrom.com/pub/os2/dev32/
747 ftp://ftp.cdrom.com/pub/os2/emx09c/
749 It is reported that the following archives contain enough utils to
750 build perl: gnufutil.zip, gnusutil.zip, gnututil.zip, gnused.zip,
751 gnupatch.zip, gnuawk.zip, gnumake.zip and ksh527rt.zip. Note that
752 all these utilities are known to be available from LEO:
754 ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu
756 Make sure that no copies or perl are currently running. Later steps
757 of the build may fail since an older version of perl.dll loaded into
760 Also make sure that you have F</tmp> directory on the current drive,
761 and F<.> directory in your C<LIBPATH>. One may try to correct the
766 if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
768 Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
769 script in F</emx/lib> directory.
771 Check that you have link386 installed. It comes standard with OS/2,
772 but may be not installed due to customization. If typing
776 shows you do not have it, do I<Selective install>, and choose C<Link
777 object modules> in I<Optional system utilities/More>. If you get into
778 link386, press C<Ctrl-C>.
780 =head2 Getting perl source
782 You need to fetch the latest perl source (including developers
783 releases). With some probability it is located in
785 http://www.perl.com/CPAN/src/5.0
786 http://www.perl.com/CPAN/src/5.0/unsupported
788 If not, you may need to dig in the indices to find it in the directory
789 of the current maintainer.
791 Quick cycle of developers release may break the OS/2 build time to
794 http://www.perl.com/CPAN/ports/os2/ilyaz/
796 may indicate the latest release which was publicly released by the
797 maintainer. Note that the release may include some additional patches
798 to apply to the current source of perl.
802 tar vzxf perl5.00409.tar.gz
804 You may see a message about errors while extracting F<Configure>. This is
805 because there is a conflict with a similarly-named file F<configure>.
807 Change to the directory of extraction.
809 =head2 Application of the patches
811 You need to apply the patches in F<./os2/diff.*> and
812 F<./os2/POSIX.mkfifo> like this:
814 gnupatch -p0 < os2\POSIX.mkfifo
815 gnupatch -p0 < os2\diff.configure
817 You may also need to apply the patches supplied with the binary
818 distribution of perl.
820 Note also that the F<db.lib> and F<db.a> from the EMX distribution
821 are not suitable for multi-threaded compile (note that currently perl
822 is not multithread-safe, but is compiled as multithreaded for
823 compatibility with XFree86-OS/2). Get a corrected one from
825 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
827 To make C<-p> filetest work, one may also need to apply the following patch
830 --- /emx/include/sys/stat.h.orig Thu May 23 13:48:16 1996
831 +++ /emx/include/sys/stat.h Sun Jul 12 14:11:32 1998
832 @@ -53,7 +53,7 @@ struct stat
835 #if !defined (S_IFMT)
836 -#define S_IFMT 0160000 /* Mask for file type */
837 +#define S_IFMT 0170000 /* Mask for file type */
838 #define S_IFIFO 0010000 /* Pipe */
839 #define S_IFCHR 0020000 /* Character device */
840 #define S_IFDIR 0040000 /* Directory */
845 You may look into the file F<./hints/os2.sh> and correct anything
846 wrong you find there. I do not expect it is needed anywhere.
850 sh Configure -des -D prefix=f:/perllib
852 C<prefix> means: where to install the resulting perl library. Giving
853 correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
854 see L<"PERLLIB_PREFIX">.
856 I<Ignore the message about missing C<ln>, and about C<-c> option to
857 tr>. In fact if you can trace where the latter spurious warning
858 comes from, please inform me.
864 At some moment the built may die, reporting a I<version mismatch> or
865 I<unable to run F<perl>>. This means that most of the build has been
866 finished, and it is the time to move the constructed F<perl.dll> to
867 some I<absolute> location in LIBPATH. After this is done the build
868 should finish without a lot of fuss. I<One can avoid the interruption
869 if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
870 probably this is not needed anymore, since F<miniperl.exe> is linked
873 Warnings which are safe to ignore: I<mkfifo() redefined> inside
878 If you haven't yet moved perl.dll onto LIBPATH, do it now (alternatively, if
879 you have a previous perl installation you'd rather not disrupt until this one
880 is installed, copy perl.dll to the t directory).
886 Some tests (4..6) should fail. Some perl invocations should end in a
887 segfault (system error C<SYS3175>). To get finer error reports, call
891 The report you get may look like
893 Failed Test Status Wstat Total Fail Failed List of failed
894 ---------------------------------------------------------------
895 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
896 lib/io_pipe.t 3 768 6 ?? % ??
897 lib/io_sock.t 3 768 5 ?? % ??
898 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
899 Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
901 Note that using C<make test> target two more tests may fail: C<op/exec:1>
902 because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
903 that the buffers are not flushed on C<_exit> (this is a bug in the test
904 which assumes that tty output is buffered).
906 I submitted a patch to EMX which makes it possible to fork() with EMX
907 dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
908 that soon the number of failing tests may decrease yet more.
910 However, the test F<lib/io_udp.t> is disabled, since it never terminates, I
911 do not know why. Comments/fixes welcome.
913 The reasons for failed tests are:
919 Checks I<file system> operations. Tests:
925 Check C<link()> and C<inode count> - nonesuch under OS/2.
929 Checks C<atime> and C<mtime> of C<stat()> - I could not understand this test.
933 Checks C<truncate()> on a filehandle just opened for write - I do not
934 know why this should or should not work.
938 =item F<lib/io_pipe.t>
940 Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
941 dynamic extension loaded - unsupported now.
943 =item F<lib/io_sock.t>
945 Checks C<IO::Socket> module. Some feature of EMX - test fork()s
946 with dynamic extension loaded - unsupported now.
950 Checks C<stat()>. Tests:
956 Checks C<inode count> - nonesuch under OS/2.
960 Checks C<mtime> and C<ctime> of C<stat()> - I could not understand this test.
964 Checks C<-x> - determined by the file extension only under OS/2.
972 Checks C<-t> of F</dev/null>. Should not fail!
978 In addition to errors, you should get a lot of warnings.
982 =item A lot of C<bad free>
984 in databases related to Berkeley DB. This is a confirmed bug of
985 DB. You may disable this warnings, see L<"PERL_BADFREE">.
987 =item Process terminated by SIGTERM/SIGINT
989 This is a standard message issued by OS/2 applications. *nix
990 applications die in silence. It is considered a feature. One can
991 easily disable this by appropriate sighandlers.
993 However the test engine bleeds these message to screen in unexpected
994 moments. Two messages of this kind I<should> be present during
997 =item F<*/sh.exe>: ln: not found
999 =item C<ls>: /dev: No such file or directory
1001 The last two should be self-explanatory. The test suite discovers that
1002 the system it runs on is not I<that much> *nixish.
1006 A lot of C<bad free>... in databases, bug in DB confirmed on other
1007 platforms. You may disable it by setting PERL_BADFREE environment variable
1010 =head2 Installing the built perl
1012 If you haven't yet moved perl.dll onto LIBPATH, do it now.
1018 It would put the generated files into needed locations. Manually put
1019 F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
1020 PATH, F<perl.dll> to a location on your LIBPATH.
1024 make cmdscripts INSTALLCMDDIR=d:/ir/on/path
1026 to convert perl utilities to F<.cmd> files and put them on
1027 PATH. You need to put F<.EXE>-utilities on path manually. They are
1028 installed in C<$prefix/bin>, here C<$prefix> is what you gave to
1029 F<Configure>, see L<Making>.
1031 =head2 C<a.out>-style build
1033 Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
1042 Manually put F<perl_.exe> to a location on your PATH.
1044 Since C<perl_> has the extensions prebuilt, it does not suffer from
1045 the I<dynamic extensions + fork()> syndrome, thus the failing tests
1048 Failed Test Status Wstat Total Fail Failed List of failed
1049 ---------------------------------------------------------------
1050 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
1051 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
1052 Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
1054 B<Note.> The build process for C<perl_> I<does not know> about all the
1055 dependencies, so you should make sure that anything is up-to-date,
1064 =head2 Some C</> became C<\> in pdksh.
1066 You have a very old pdksh. See L<Prerequisites>.
1068 =head2 C<'errno'> - unresolved external
1070 You do not have MT-safe F<db.lib>. See L<Prerequisites>.
1072 =head2 Problems with tr or sed
1074 reported with very old version of tr and sed.
1076 =head2 Some problem (forget which ;-)
1078 You have an older version of F<perl.dll> on your LIBPATH, which
1079 broke the build of extensions.
1081 =head2 Library ... not found
1083 You did not run C<omflibs>. See L<Prerequisites>.
1085 =head2 Segfault in make
1087 You use an old version of GNU make. See L<Prerequisites>.
1089 =head1 Specific (mis)features of OS/2 port
1091 =head2 C<setpriority>, C<getpriority>
1093 Note that these functions are compatible with *nix, not with the older
1094 ports of '94 - 95. The priorities are absolute, go from 32 to -95,
1095 lower is quicker. 0 is the default priority.
1099 Multi-argument form of C<system()> allows an additional numeric
1100 argument. The meaning of this argument is described in
1103 =head2 C<extproc> on the first line
1105 If the first chars of a script are C<"extproc ">, this line is treated
1106 as C<#!>-line, thus all the switches on this line are processed (twice
1107 if script was started via cmd.exe).
1109 =head2 Additional modules:
1111 L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. These
1112 modules provide access to additional numeric argument for C<system>
1113 and to the list of the running processes,
1114 to DLLs having functions with REXX signature and to REXX runtime, to
1115 OS/2 databases in the F<.INI> format, and to Extended Attributes.
1117 Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
1118 C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
1120 =head2 Prebuilt methods:
1124 =item C<File::Copy::syscopy>
1126 used by C<File::Copy::copy>, see L<File::Copy>.
1128 =item C<DynaLoader::mod2fname>
1130 used by C<DynaLoader> for DLL name mangling.
1132 =item C<Cwd::current_drive()>
1136 =item C<Cwd::sys_chdir(name)>
1138 leaves drive as it is.
1140 =item C<Cwd::change_drive(name)>
1143 =item C<Cwd::sys_is_absolute(name)>
1145 means has drive letter and is_rooted.
1147 =item C<Cwd::sys_is_rooted(name)>
1149 means has leading C<[/\\]> (maybe after a drive-letter:).
1151 =item C<Cwd::sys_is_relative(name)>
1153 means changes with current dir.
1155 =item C<Cwd::sys_cwd(name)>
1157 Interface to cwd from EMX. Used by C<Cwd::cwd>.
1159 =item C<Cwd::sys_abspath(name, dir)>
1161 Really really odious function to implement. Returns absolute name of
1162 file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1165 =item C<Cwd::extLibpath([type])
1167 Get current value of extended library search path. If C<type> is
1168 present and I<true>, works with END_LIBPATH, otherwise with
1171 =item C<Cwd::extLibpath_set( path [, type ] )>
1173 Set current value of extended library search path. If C<type> is
1174 present and I<true>, works with END_LIBPATH, otherwise with
1179 (Note that some of these may be moved to different libraries -
1189 Since L<flock(3)> is present in EMX, but is not functional, it is
1190 emulated by perl. To disable the emulations, set environment variable
1191 C<USE_PERL_FLOCK=0>.
1195 Here is the list of things which may be "broken" on
1196 EMX (from EMX docs):
1202 The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not
1207 L<sock_init(3)> is not required and not implemented.
1211 L<flock(3)> is not yet implemented (dummy function). (Perl has a workaround.)
1215 L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1223 waitpid() is not implemented for negative values of PID.
1227 Note that C<kill -9> does not work with the current version of EMX.
1231 Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
1232 of F<sh.exe> plague perl as well.
1234 In particular, uppercase letters do not work in C<[...]>-patterns with
1239 =head2 Modifications
1241 Perl modifies some standard C library calls in the following ways:
1247 C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
1251 is created using C<TMP> or C<TEMP> environment variable, via
1256 If the current directory is not writable, file is created using modified
1257 C<tmpnam>, so there may be a race condition.
1261 a dummy implementation.
1265 C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1269 Since L<flock(3)> is present in EMX, but is not functional, it is
1270 emulated by perl. To disable the emulations, set environment variable
1271 C<USE_PERL_FLOCK=0>.
1277 Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
1278 same basket (though EMX environment tries hard to overcome this
1279 limitations, so the situation may somehow improve). There are 4
1280 executables for Perl provided by the distribution:
1284 The main workhorse. This is a chimera executable: it is compiled as an
1285 C<a.out>-style executable, but is linked with C<omf>-style dynamic
1286 library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1289 It can load perl dynamic extensions, and it can fork(). Unfortunately,
1290 with the current version of EMX it cannot fork() with dynamic
1291 extensions loaded (may be fixed by patches to EMX).
1293 B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1297 This is a statically linked C<a.out>-style executable. It can fork(),
1298 but cannot load dynamic Perl extensions. The supplied executable has a
1299 lot of extensions prebuilt, thus there are situations when it can
1300 perform tasks not possible using F<perl.exe>, like fork()ing when
1301 having some standard extension loaded. This executable is a VIO
1304 B<Note.> A better behaviour could be obtained from C<perl.exe> if it
1305 were statically linked with standard I<Perl extensions>, but
1306 dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
1307 be able to fork() with standard extensions, I<and> would be able to
1308 dynamically load arbitrary extensions. Some changes to Makefiles and
1309 hint files should be necessary to achieve this.
1311 I<This is also the only executable with does not require OS/2.> The
1312 friends locked into C<M$> world would appreciate the fact that this
1313 executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
1314 appropriate extender. See L<"Other OSes">.
1316 =head2 F<perl__.exe>
1318 This is the same executable as F<perl___.exe>, but it is a PM
1321 B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
1322 application are redirected to C<nul>. However, it is possible to see
1323 them if you start C<perl__.exe> from a PM program which emulates a
1324 console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
1325 possible> to use Perl debugger (see L<perldebug>) to debug your PM
1328 This flavor is required if you load extensions which use PM, like
1329 the forthcoming C<Perl/Tk>.
1331 =head2 F<perl___.exe>
1333 This is an C<omf>-style executable which is dynamically linked to
1334 F<perl.dll> and CRT DLL. I know no advantages of this executable
1335 over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1336 that the build process is not so convoluted as with C<perl.exe>.
1338 It is a VIO application.
1340 =head2 Why strange names?
1342 Since Perl processes the C<#!>-line (cf.
1343 L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1344 L<perldiag/"Not a perl script">,
1345 L<perldiag/"No Perl script found in input">), it should know when a
1346 program I<is a Perl>. There is some naming convention which allows
1347 Perl to distinguish correct lines from wrong ones. The above names are
1348 almost the only names allowed by this convention which do not contain
1349 digits (which have absolutely different semantics).
1351 =head2 Why dynamic linking?
1353 Well, having several executables dynamically linked to the same huge
1354 library has its advantages, but this would not substantiate the
1355 additional work to make it compile. The reason is stupid-but-quick
1356 "hard" dynamic linking used by OS/2.
1358 The address tables of DLLs are patched only once, when they are
1359 loaded. The addresses of entry points into DLLs are guaranteed to be
1360 the same for all programs which use the same DLL, which reduces the
1361 amount of runtime patching - once DLL is loaded, its code is
1364 While this allows some performance advantages, this makes life
1365 terrible for developers, since the above scheme makes it impossible
1366 for a DLL to be resolved to a symbol in the .EXE file, since this
1367 would need a DLL to have different relocations tables for the
1368 executables which use it.
1370 However, a Perl extension is forced to use some symbols from the perl
1371 executable, say to know how to find the arguments provided on the perl
1372 internal evaluation stack. The solution is that the main code of
1373 interpreter should be contained in a DLL, and the F<.EXE> file just loads
1374 this DLL into memory and supplies command-arguments.
1376 This I<greatly> increases the load time for the application (as well as
1377 the number of problems during compilation). Since interpreter is in a DLL,
1378 the CRT is basically forced to reside in a DLL as well (otherwise
1379 extensions would not be able to use CRT).
1381 =head2 Why chimera build?
1383 Current EMX environment does not allow DLLs compiled using Unixish
1384 C<a.out> format to export symbols for data. This forces C<omf>-style
1385 compile of F<perl.dll>.
1387 Current EMX environment does not allow F<.EXE> files compiled in
1388 C<omf> format to fork(). fork() is needed for exactly three Perl
1393 =item explicit fork()
1401 opening pipes to itself.
1405 While these operations are not questions of life and death, a lot of
1406 useful scripts use them. This forces C<a.out>-style compile of
1412 Here we list environment variables with are either OS/2- and DOS- and
1413 Win*-specific, or are more important under OS/2 than under other OSes.
1415 =head2 C<PERLLIB_PREFIX>
1417 Specific for EMX port. Should have the form
1425 If the beginning of some prebuilt path matches F<path1>, it is
1426 substituted with F<path2>.
1428 Should be used if the perl library is moved from the default
1429 location in preference to C<PERL(5)LIB>, since this would not leave wrong
1430 entries in @INC. Say, if the compiled version of perl looks for @INC
1431 in F<f:/perllib/lib>, and you want to install the library in
1434 set PERLLIB_PREFIX=f:/perllib/lib;h:/opt/gnu
1436 =head2 C<PERL_BADLANG>
1438 If 1, perl ignores setlocale() failing. May be useful with some
1441 =head2 C<PERL_BADFREE>
1443 If 1, perl would not warn of in case of unwarranted free(). May be
1444 useful in conjunction with the module DB_File, since Berkeley DB
1445 memory handling code is buggy.
1447 =head2 C<PERL_SH_DIR>
1449 Specific for EMX port. Gives the directory part of the location for
1452 =head2 C<USE_PERL_FLOCK>
1454 Specific for EMX port. Since L<flock(3)> is present in EMX, but is not
1455 functional, it is emulated by perl. To disable the emulations, set
1456 environment variable C<USE_PERL_FLOCK=0>.
1458 =head2 C<TMP> or C<TEMP>
1460 Specific for EMX port. Used as storage place for temporary files, most
1461 notably C<-e> scripts.
1465 Here we list major changes which could make you by surprise.
1469 C<setpriority> and C<getpriority> are not compatible with earlier
1470 ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1472 =head2 DLL name mangling
1474 With the release 5.003_01 the dynamically loadable libraries
1475 should be rebuilt. In particular, DLLs are now created with the names
1476 which contain a checksum, thus allowing workaround for OS/2 scheme of
1481 As of release 5.003_01 perl is linked to multithreaded CRT
1482 DLL. If perl itself is not compiled multithread-enabled, so will not be perl
1483 malloc(). However, extensions may use multiple thread on their own
1486 Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
1488 =head2 Calls to external programs
1490 Due to a popular demand the perl external program calling has been
1491 changed wrt Andreas Kaiser's port. I<If> perl needs to call an
1492 external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1493 whatever is the override, see L<"PERL_SH_DIR">.
1495 Thus means that you need to get some copy of a F<sh.exe> as well (I
1496 use one from pdksh). The drive F<F:> above is set up automatically during
1497 the build to a correct value on the builder machine, but is
1498 overridable at runtime,
1500 B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1501 one non-overridable shell per platform. The obvious choices for OS/2
1502 are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
1503 with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
1504 100% compatibility with the scripts coming from *nix. As an added benefit
1505 this works as well under DOS if you use DOS-enabled port of pdksh
1506 (see L<"Prerequisites">).
1508 B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
1509 via fork()/exec(), and there is I<no> functioning exec() on
1510 OS/2. exec() is emulated by EMX by asyncroneous call while the caller
1511 waits for child completion (to pretend that the C<pid> did not change). This
1512 means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1513 which may lead to some resources taken from the system (even if we do
1514 not count extra work needed for fork()ing).
1516 Note that this a lesser issue now when we do not spawn F<sh.exe>
1517 unless needed (metachars found).
1519 One can always start F<cmd.exe> explicitly via
1521 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1523 If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
1524 scripts, the long-term solution proposed on p5-p is to have a directive
1528 which will override system(), exec(), C<``>, and
1529 C<open(,'...|')>. With current perl you may override only system(),
1530 readpipe() - the explicit version of C<``>, and maybe exec(). The code
1531 will substitute the one-argument call to system() by
1532 C<CORE::system('cmd.exe', '/c', shift)>.
1534 If you have some working code for C<OS2::Cmd>, please send it to me,
1535 I will include it into distribution. I have no need for such a module, so
1538 For the details of the current situation with calling external programs,
1539 see L<Starting OS/2 (and DOS) programs under Perl>.
1545 External scripts may be called by name. Perl will try the same extensions
1546 as when processing B<-S> command-line switch.
1550 =head2 Memory allocation
1552 Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
1553 for speed, but perl is not, since its malloc is lightning-fast.
1554 Unfortunately, it is also quite frivolous with memory usage as well.
1556 Since kitchen-top machines are usually low on memory, perl is compiled with
1557 all the possible memory-saving options. This probably makes perl's
1558 malloc() as greedy with memory as the neighbor's malloc(), but still
1559 much quickier. Note that this is true only for a "typical" usage,
1560 it is possible that the perl malloc will be worse for some very special usage.
1562 Combination of perl's malloc() and rigid DLL name resolution creates
1563 a special problem with library functions which expect their return value to
1564 be free()d by system's free(). To facilitate extensions which need to call
1565 such functions, system memory-allocation functions are still available with
1566 the prefix C<emx_> added. (Currently only DLL perl has this, it should
1567 propagate to F<perl_.exe> shortly.)
1573 I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
1574 into my ftp directory, mirrored on CPAN. I made
1575 some minor changes needed to compile them by standard tools. I cannot
1576 test UPM and FTP, so I will appreciate your feedback. Other extensions
1577 there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1578 files - and maybe some other extensions at the time you read it.
1580 Note that OS2 perl defines 2 pseudo-extension functions
1581 OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1582 L<Prebuilt methods>).
1584 The -R switch of older perl is deprecated. If you need to call a REXX code
1585 which needs access to variables, include the call into a REXX compartment
1587 REXX_call {...block...};
1589 Two new functions are supported by REXX code,
1591 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1593 If you have some other extensions you want to share, send the code to
1594 me. At least two are available: tied access to EA's, and tied access
1595 to system databases.
1599 Ilya Zakharevich, ilya@math.ohio-state.edu