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
123 The target is to make OS/2 the best supported platform for
124 using/building/developing Perl and I<Perl applications>, as well as
125 make Perl the best language to use under OS/2. The secondary target is
126 to try to make this work under DOS and Win* as well (but not B<too> hard).
128 The current state is quite close to this target. Known limitations:
134 Some *nix programs use fork() a lot, but currently fork() is not
135 supported after I<use>ing dynamically loaded extensions.
139 You need a separate perl executable F<perl__.exe> (see L<perl__.exe>)
140 to use PM code in your application (like the forthcoming Perl/Tk).
144 There is no simple way to access WPS objects. The only way I know
145 is via C<OS2::REXX> extension (see L<OS2::REXX>), and we do not have access to
146 convenience methods of Object-REXX. (Is it possible at all? I know
147 of no Object-REXX API.)
151 Please keep this list up-to-date by informing me about other items.
155 Since OS/2 port of perl uses a remarkable EMX environment, it can
156 run (and build extensions, and - possibly - be build itself) under any
157 environment which can run EMX. The current list is DOS,
158 DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors,
159 only one works, see L<"perl_.exe">.
161 Note that not all features of Perl are available under these
162 environments. This depends on the features the I<extender> - most
163 probably RSX - decided to implement.
165 Cf. L<Prerequisites>.
173 EMX runtime is required (may be substituted by RSX). Note that
174 it is possible to make F<perl_.exe> to run under DOS without any
175 external support by binding F<emx.exe>/F<rsx.exe> to it, see L<emxbind>. Note
176 that under DOS for best results one should use RSX runtime, which
177 has much more functions working (like C<fork>, C<popen> and so on). In
178 fact RSX is required if there is no VCPI present. Note the
181 Only the latest runtime is supported, currently C<0.9c>. Perl may run
182 under earlier versions of EMX, but this is not tested.
184 One can get different parts of EMX from, say
186 ftp://ftp.cdrom.com/pub/os2/emx09c/
187 ftp://hobbes.nmsu.edu/os2/unix/emx09c/
189 The runtime component should have the name F<emxrt.zip>.
191 B<NOTE>. It is enough to have F<emx.exe>/F<rsx.exe> on your path. One
192 does not need to specify them explicitly (though this
200 To run Perl on DPMI platforms one needs RSX runtime. This is
201 needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see
202 L<"Other OSes">). RSX would not work with VCPI
203 only, as EMX would, it requires DMPI.
205 Having RSX and the latest F<sh.exe> one gets a fully functional
206 B<*nix>-ish environment under DOS, say, C<fork>, C<``> and
207 pipe-C<open> work. In fact, MakeMaker works (for static build), so one
208 can have Perl development environment under DOS.
210 One can get RSX from, say
212 ftp://ftp.cdrom.com/pub/os2/emx09c/contrib
213 ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc
214 ftp://ftp.leo.org/pub/comp/os/os2/leo/devtools/emx+gcc/contrib
216 Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
218 The latest F<sh.exe> with DOS hooks is available at
220 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
224 Perl does not care about file systems, but to install the whole perl
225 library intact one needs a file system which supports long file names.
227 Note that if you do not plan to build the perl itself, it may be
228 possible to fool EMX to truncate file names. This is not supported,
229 read EMX docs to see how to do it.
233 To start external programs with complicated command lines (like with
234 pipes in between, and/or quoting of arguments), Perl uses an external
235 shell. With EMX port such shell should be named <sh.exe>, and located
236 either in the wired-in-during-compile locations (usually F<F:/bin>),
237 or in configurable location (see L<"PERL_SH_DIR">).
239 For best results use EMX pdksh. The soon-to-be-available standard
240 binary (5.2.12?) runs under DOS (with L<RSX>) as well, meanwhile use
243 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
247 =head2 Starting Perl programs under OS/2 (and DOS and...)
249 Start your Perl program F<foo.pl> with arguments C<arg1 arg2 arg3> the
250 same way as on any other platform, by
252 perl foo.pl arg1 arg2 arg3
254 If you want to specify perl options C<-my_opts> to the perl itself (as
255 opposed to to your program), use
257 perl -my_opts foo.pl arg1 arg2 arg3
259 Alternately, if you use OS/2-ish shell, like CMD or 4os2, put
260 the following at the start of your perl script:
262 extproc perl -S -my_opts
264 rename your program to F<foo.cmd>, and start it by typing
268 Note that because of stupid OS/2 limitations the full path of the perl
269 script is not available when you use C<extproc>, thus you are forced to
270 use C<-S> perl switch, and your script should be on path. As a plus
271 side, if you know a full path to your script, you may still start it
274 perl ../../blah/foo.cmd arg1 arg2 arg3
276 (note that the argument C<-my_opts> is taken care of by the C<extproc> line
277 in your script, see L<C<extproc> on the first line>).
279 To understand what the above I<magic> does, read perl docs about C<-S>
280 switch - see L<perlrun>, and cmdref about C<extproc>:
287 or whatever method you prefer.
289 There are also endless possibilities to use I<executable extensions> of
290 4os2, I<associations> of WPS and so on... However, if you use
291 *nixish shell (like F<sh.exe> supplied in the binary distribution),
292 you need to follow the syntax specified in L<perlrun/"Switches">.
294 Note that B<-S> switch enables a search with additional extensions
295 F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well.
297 =head2 Starting OS/2 (and DOS) programs under Perl
299 This is what system() (see L<perlfunc/system>), C<``> (see
300 L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
301 are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
304 Note however that to use some of these operators you need to have a
305 sh-syntax shell installed (see L<"Pdksh">,
306 L<"Frequently asked questions">), and perl should be able to find it
307 (see L<"PERL_SH_DIR">).
309 The cases when the shell is used are:
315 One-argument system() (see L<perlfunc/system>), exec() (see L<perlfunc/exec>)
316 with redirection or shell meta-characters;
320 Pipe-open (see L<perlfunc/open>) with the command which contains redirection
321 or shell meta-characters;
325 Backticks C<``> (see L<perlop/"I/O Operators">) with the command which contains
326 redirection or shell meta-characters;
330 If the executable called by system()/exec()/pipe-open()/C<``> is a script
331 with the "magic" C<#!> line or C<extproc> line which specifies shell;
335 If the executable called by system()/exec()/pipe-open()/C<``> is a script
336 without "magic" line, and C<$ENV{EXECSHELL}> is set to shell;
340 If the executable called by system()/exec()/pipe-open()/C<``> is not
345 For globbing (see L<perlfunc/glob>, L<perlop/"I/O Operators">).
349 For the sake of speed for a common case, in the above algorithms
350 backslashes in the command name are not considered as shell metacharacters.
352 Perl starts scripts which begin with cookies
353 C<extproc> or C<#!> directly, without an intervention of shell. Perl uses the
354 same algorithm to find the executable as F<pdksh>: if the path
355 on C<#!> line does not work, and contains C</>, then the executable
356 is searched in F<.> and on C<PATH>. To find arguments for these scripts
357 Perl uses a different algorithm than F<pdksh>: up to 3 arguments are
358 recognized, and trailing whitespace is stripped.
361 does not contain such a cooky, then to avoid calling F<sh.exe>, Perl uses
362 the same algorithm as F<pdksh>: if C<$ENV{EXECSHELL}> is set, the
363 script is given as the first argument to this command, if not set, then
364 C<$ENV{COMSPEC} /c> is used (or a hardwired guess if C<$ENV{COMSPEC}> is
367 If starting scripts directly, Perl will use exactly the same algorithm as for
368 the search of script given by B<-S> command-line option: it will look in
369 the current directory, then on components of C<$ENV{PATH}> using the
370 following order of appended extensions: no extension, F<.cmd>, F<.btm>,
373 Note that Perl will start to look for scripts only if OS/2 cannot start the
374 specified application, thus C<system 'blah'> will not look for a script if
375 there is an executable file F<blah.exe> I<anywhere> on C<PATH>.
377 Note also that executable files on OS/2 can have an arbitrary extension,
378 but F<.exe> will be automatically appended if no dot is present in the name.
379 The workaround as as simple as that: since F<blah.> and F<blah> denote the
380 same file, to start an executable residing in file F<n:/bin/blah> (no
381 extension) give an argument C<n:/bin/blah.> to system().
383 The last note is that currently it is not straightforward to start PM
384 programs from VIO (=text-mode) Perl process and visa versa. Either ensure
385 that shell will be used, as in C<system 'cmd /c epm'>, or start it using
386 optional arguments to system() documented in C<OS2::Process> module. This
387 is considered a bug and should be fixed soon.
390 =head1 Frequently asked questions
392 =head2 I cannot run external programs
398 Did you run your programs with C<-w> switch? See
399 L<Starting OS/2 (and DOS) programs under Perl>.
403 Do you try to run I<internal> shell commands, like C<`copy a b`>
404 (internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
405 need to specify your shell explicitly, like C<`cmd /c copy a b`>,
406 since Perl cannot deduce which commands are internal to your shell.
410 =head2 I cannot embed perl into my program, or use F<perl.dll> from my
415 =item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
417 If not, you need to build a stand-alone DLL for perl. Contact me, I
418 did it once. Sockets would not work, as a lot of other stuff.
420 =item Did you use L<ExtUtils::Embed>?
422 I had reports it does not work. Somebody would need to fix it.
426 =head2 C<``> and pipe-C<open> do not work under DOS.
428 This may a variant of just L<"I cannot run external programs">, or a
429 deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
430 for these commands to work, and you may need a port of F<sh.exe> which
431 understands command arguments. One of such ports is listed in
432 L<"Prerequisites"> under RSX. Do not forget to set variable
433 C<L<"PERL_SH_DIR">> as well.
435 DPMI is required for RSX.
437 =head2 Cannot start C<find.exe "pattern" file>
441 system 'cmd', '/c', 'find "pattern" file';
442 `cmd /c 'find "pattern" file'`
444 This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
445 C<perl.exe>, but this is a price to pay if you want to use
446 non-conforming program. In fact F<find.exe> cannot be started at all
447 using C library API only. Otherwise the following command-lines were
455 =head2 Automatic binary installation
457 The most convenient way of installing perl is via perl installer
458 F<install.exe>. Just follow the instructions, and 99% of the
459 installation blues would go away.
461 Note however, that you need to have F<unzip.exe> on your path, and
462 EMX environment I<running>. The latter means that if you just
463 installed EMX, and made all the needed changes to F<Config.sys>,
464 you may need to reboot in between. Check EMX runtime by running
468 A folder is created on your desktop which contains some useful
471 B<Things not taken care of by automatic binary installation:>
475 =item C<PERL_BADLANG>
477 may be needed if you change your codepage I<after> perl installation,
478 and the new value is not supported by EMX. See L<"PERL_BADLANG">.
480 =item C<PERL_BADFREE>
482 see L<"PERL_BADFREE">.
486 This file resides somewhere deep in the location you installed your
487 perl library, find it out by
489 perl -MConfig -le "print $INC{'Config.pm'}"
491 While most important values in this file I<are> updated by the binary
492 installer, some of them may need to be hand-edited. I know no such
493 data, please keep me informed if you find one.
497 B<NOTE>. Because of a typo the binary installer of 5.00305
498 would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
499 remove this variable and put C<L<PERL_SH_DIR>> instead.
501 =head2 Manual binary installation
503 As of version 5.00305, OS/2 perl binary distribution comes split
504 into 11 components. Unfortunately, to enable configurable binary
505 installation, the file paths in the zip files are not absolute, but
506 relative to some directory.
508 Note that the extraction with the stored paths is still necessary
509 (default with unzip, specify C<-d> to pkunzip). However, you
510 need to know where to extract the files. You need also to manually
511 change entries in F<Config.sys> to reflect where did you put the
512 files. Note that if you have some primitive unzipper (like
513 pkunzip), you may get a lot of warnings/errors during
514 unzipping. Upgrade to C<(w)unzip>.
516 Below is the sample of what to do to reproduce the configuration on my
521 =item Perl VIO and PM executables (dynamically linked)
523 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
524 unzip perl_exc.zip *.dll -d f:/emx.add/dll
526 (have the directories with C<*.exe> on PATH, and C<*.dll> on
529 =item Perl_ VIO executable (statically linked)
531 unzip perl_aou.zip -d f:/emx.add/bin
533 (have the directory on PATH);
535 =item Executables for Perl utilities
537 unzip perl_utl.zip -d f:/emx.add/bin
539 (have the directory on PATH);
541 =item Main Perl library
543 unzip perl_mlb.zip -d f:/perllib/lib
545 If this directory is preserved, you do not need to change
546 anything. However, for perl to find it if it is changed, you need to
547 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
549 =item Additional Perl modules
551 unzip perl_ste.zip -d f:/perllib/lib/site_perl
553 If you do not change this directory, do nothing. Otherwise put this
554 directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
555 variable. Do not use C<PERL5LIB> unless you have it set already. See
556 L<perl/"ENVIRONMENT">.
558 =item Tools to compile Perl modules
560 unzip perl_blb.zip -d f:/perllib/lib
562 If this directory is preserved, you do not need to change
563 anything. However, for perl to find it if it is changed, you need to
564 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
566 =item Manpages for Perl and utilities
568 unzip perl_man.zip -d f:/perllib/man
570 This directory should better be on C<MANPATH>. You need to have a
571 working man to access these files.
573 =item Manpages for Perl modules
575 unzip perl_mam.zip -d f:/perllib/man
577 This directory should better be on C<MANPATH>. You need to have a
578 working man to access these files.
580 =item Source for Perl documentation
582 unzip perl_pod.zip -d f:/perllib/lib
584 This is used by by C<perldoc> program (see L<perldoc>), and may be used to
585 generate HTML documentation usable by WWW browsers, and
586 documentation in zillions of other formats: C<info>, C<LaTeX>,
587 C<Acrobat>, C<FrameMaker> and so on.
589 =item Perl manual in F<.INF> format
591 unzip perl_inf.zip -d d:/os2/book
593 This directory should better be on C<BOOKSHELF>.
597 unzip perl_sh.zip -d f:/bin
599 This is used by perl to run external commands which explicitly
600 require shell, like the commands using I<redirection> and I<shell
601 metacharacters>. It is also used instead of explicit F</bin/sh>.
603 Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
606 B<Note.> It may be possible to use some other sh-compatible shell
611 After you installed the components you needed and updated the
612 F<Config.sys> correspondingly, you need to hand-edit
613 F<Config.pm>. This file resides somewhere deep in the location you
614 installed your perl library, find it out by
616 perl -MConfig -le "print $INC{'Config.pm'}"
618 You need to correct all the entries which look like file paths (they
619 currently start with C<f:/>).
623 The automatic and manual perl installation leave precompiled paths
624 inside perl executables. While these paths are overwriteable (see
625 L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
626 binary editing of paths inside the executables/DLLs.
628 =head1 Accessing documentation
630 Depending on how you built/installed perl you may have (otherwise
631 identical) Perl documentation in the following formats:
633 =head2 OS/2 F<.INF> file
635 Most probably the most convenient form. Under OS/2 view it as
640 view perl ExtUtils::MakeMaker
642 (currently the last two may hit a wrong location, but this may improve
643 soon). Under Win* see L<"SYNOPSIS">.
645 If you want to build the docs yourself, and have I<OS/2 toolkit>, run
649 in F</perllib/lib/pod> directory, then
653 (Expect a lot of errors during the both steps.) Now move it on your
658 If you have perl documentation in the source form, perl utilities
659 installed, and GNU groff installed, you may use
663 perldoc ExtUtils::MakeMaker
665 to access the perl documentation in the text form (note that you may get
666 better results using perl manpages).
668 Alternately, try running pod2text on F<.pod> files.
672 If you have man installed on your system, and you installed perl
673 manpages, use something like this:
677 man ExtUtils.MakeMaker
679 to access documentation for different components of Perl. Start with
683 Note that dot (F<.>) is used as a package separator for documentation
684 for packages, and as usual, sometimes you need to give the section - C<3>
685 above - to avoid shadowing by the I<less(1) manpage>.
687 Make sure that the directory B<above> the directory with manpages is
688 on our C<MANPATH>, like this
690 set MANPATH=c:/man;f:/perllib/man
694 If you have some WWW browser available, installed the Perl
695 documentation in the source form, and Perl utilities, you can build
696 HTML docs. Cd to directory with F<.pod> files, and do like this
698 cd f:/perllib/lib/pod
701 After this you can direct your browser the file F<perl.html> in this
702 directory, and go ahead with reading docs, like this:
704 explore file:///f:/perllib/lib/pod/perl.html
706 Alternatively you may be able to get these docs prebuilt from CPAN.
708 =head2 GNU C<info> files
710 Users of Emacs would appreciate it very much, especially with
711 C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
712 or, alternately, prebuilt info pages.
716 for C<Acrobat> are available on CPAN (for slightly old version of
721 can be constructed using C<pod2latex>.
725 Here we discuss how to build Perl under OS/2. There is an alternative
726 (but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
730 You need to have the latest EMX development environment, the full
731 GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
732 earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
738 ). You need the latest version of F<pdksh> installed as F<sh.exe>.
740 Check that you have B<BSD> libraries and headers installed, and -
741 optionally - Berkeley DB headers and libraries, and crypt.
743 Possible locations to get this from are
745 ftp://hobbes.nmsu.edu/os2/unix/
746 ftp://ftp.cdrom.com/pub/os2/unix/
747 ftp://ftp.cdrom.com/pub/os2/dev32/
748 ftp://ftp.cdrom.com/pub/os2/emx09c/
750 It is reported that the following archives contain enough utils to
751 build perl: gnufutil.zip, gnusutil.zip, gnututil.zip, gnused.zip,
752 gnupatch.zip, gnuawk.zip, gnumake.zip and ksh527rt.zip. Note that
753 all these utilities are known to be available from LEO:
755 ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu
757 Make sure that no copies or perl are currently running. Later steps
758 of the build may fail since an older version of perl.dll loaded into
761 Also make sure that you have F</tmp> directory on the current drive,
762 and F<.> directory in your C<LIBPATH>. One may try to correct the
767 if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
769 Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
770 script in F</emx/lib> directory.
772 Check that you have link386 installed. It comes standard with OS/2,
773 but may be not installed due to customization. If typing
777 shows you do not have it, do I<Selective install>, and choose C<Link
778 object modules> in I<Optional system utilities/More>. If you get into
779 link386, press C<Ctrl-C>.
781 =head2 Getting perl source
783 You need to fetch the latest perl source (including developers
784 releases). With some probability it is located in
786 http://www.perl.com/CPAN/src/5.0
787 http://www.perl.com/CPAN/src/5.0/unsupported
789 If not, you may need to dig in the indices to find it in the directory
790 of the current maintainer.
792 Quick cycle of developers release may break the OS/2 build time to
795 http://www.perl.com/CPAN/ports/os2/ilyaz/
797 may indicate the latest release which was publicly released by the
798 maintainer. Note that the release may include some additional patches
799 to apply to the current source of perl.
803 tar vzxf perl5.00409.tar.gz
805 You may see a message about errors while extracting F<Configure>. This is
806 because there is a conflict with a similarly-named file F<configure>.
808 Change to the directory of extraction.
810 =head2 Application of the patches
812 You need to apply the patches in F<./os2/diff.*> and
813 F<./os2/POSIX.mkfifo> like this:
815 gnupatch -p0 < os2\POSIX.mkfifo
816 gnupatch -p0 < os2\diff.configure
818 You may also need to apply the patches supplied with the binary
819 distribution of perl.
821 Note also that the F<db.lib> and F<db.a> from the EMX distribution
822 are not suitable for multi-threaded compile (note that currently perl
823 is not multithread-safe, but is compiled as multithreaded for
824 compatibility with XFree86-OS/2). Get a corrected one from
826 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
828 To make C<-p> filetest work, one may also need to apply the following patch
831 --- /emx/include/sys/stat.h.orig Thu May 23 13:48:16 1996
832 +++ /emx/include/sys/stat.h Sun Jul 12 14:11:32 1998
833 @@ -53,7 +53,7 @@ struct stat
836 #if !defined (S_IFMT)
837 -#define S_IFMT 0160000 /* Mask for file type */
838 +#define S_IFMT 0170000 /* Mask for file type */
839 #define S_IFIFO 0010000 /* Pipe */
840 #define S_IFCHR 0020000 /* Character device */
841 #define S_IFDIR 0040000 /* Directory */
846 You may look into the file F<./hints/os2.sh> and correct anything
847 wrong you find there. I do not expect it is needed anywhere.
851 sh Configure -des -D prefix=f:/perllib
853 C<prefix> means: where to install the resulting perl library. Giving
854 correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
855 see L<"PERLLIB_PREFIX">.
857 I<Ignore the message about missing C<ln>, and about C<-c> option to
858 tr>. In fact if you can trace where the latter spurious warning
859 comes from, please inform me.
865 At some moment the built may die, reporting a I<version mismatch> or
866 I<unable to run F<perl>>. This means that most of the build has been
867 finished, and it is the time to move the constructed F<perl.dll> to
868 some I<absolute> location in LIBPATH. After this is done the build
869 should finish without a lot of fuss. I<One can avoid the interruption
870 if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
871 probably this is not needed anymore, since F<miniperl.exe> is linked
874 Warnings which are safe to ignore: I<mkfifo() redefined> inside
879 If you haven't yet moved perl.dll onto LIBPATH, do it now (alternatively, if
880 you have a previous perl installation you'd rather not disrupt until this one
881 is installed, copy perl.dll to the t directory).
887 All tests should succeed (with some of them skipped). Note that on one
888 of the systems I see intermittent failures of F<io/pipe.t> subtest 9.
889 Any help to track what happens with this test is appreciated.
891 Some tests may generate extra messages similar to
895 =item A lot of C<bad free>
897 in database tests related to Berkeley DB. This is a confirmed bug of
898 DB. You may disable this warnings, see L<"PERL_BADFREE">.
900 There is not much we can do with it (but apparently it does not cause
901 any real error with data).
903 =item Process terminated by SIGTERM/SIGINT
905 This is a standard message issued by OS/2 applications. *nix
906 applications die in silence. It is considered a feature. One can
907 easily disable this by appropriate sighandlers.
909 However the test engine bleeds these message to screen in unexpected
910 moments. Two messages of this kind I<should> be present during
915 Two F<lib/io_*> tests may generate popups (system error C<SYS3175>),
916 but should succeed anyway. This is due to a bug of EMX related to
917 fork()ing with dynamically loaded libraries.
919 I submitted a patch to EMX which makes it possible to fork() with EMX
920 dynamic libraries loaded, which makes F<lib/io*> tests pass without
921 skipping offended tests. This means that soon the number of skipped tests
922 may decrease yet more.
924 To get finer test reports, call
928 The report with F<io/pipe.t> failing may look like this:
930 Failed Test Status Wstat Total Fail Failed List of failed
931 ------------------------------------------------------------
932 io/pipe.t 12 1 8.33% 9
933 7 tests skipped, plus 56 subtests skipped.
934 Failed 1/195 test scripts, 99.49% okay. 1/6542 subtests failed, 99.98% okay.
936 The reasons for most important skipped tests are:
946 Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS
947 provides only 2sec time granularity (for compatibility with FAT?).
951 Checks C<truncate()> on a filehandle just opened for write - I do not
952 know why this should or should not work.
956 =item F<lib/io_pipe.t>
958 Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
959 dynamic extension loaded - unsupported now.
961 =item F<lib/io_sock.t>
963 Checks C<IO::Socket> module. Some feature of EMX - test fork()s
964 with dynamic extension loaded - unsupported now.
968 Checks C<stat()>. Tests:
974 Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS
975 provides only 2sec time granularity (for compatibility with FAT?).
979 =item F<lib/io_udp.t>
981 It never terminates, apparently some bug in storing the last socket from
982 which we obtained a message.
986 =head2 Installing the built perl
988 If you haven't yet moved perl.dll onto LIBPATH, do it now.
994 It would put the generated files into needed locations. Manually put
995 F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
996 PATH, F<perl.dll> to a location on your LIBPATH.
1000 make cmdscripts INSTALLCMDDIR=d:/ir/on/path
1002 to convert perl utilities to F<.cmd> files and put them on
1003 PATH. You need to put F<.EXE>-utilities on path manually. They are
1004 installed in C<$prefix/bin>, here C<$prefix> is what you gave to
1005 F<Configure>, see L<Making>.
1007 =head2 C<a.out>-style build
1009 Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
1018 Manually put F<perl_.exe> to a location on your PATH.
1020 Since C<perl_> has the extensions prebuilt, it does not suffer from
1021 the I<dynamic extensions + fork()> syndrome, thus the failing tests
1024 Failed Test Status Wstat Total Fail Failed List of failed
1025 ---------------------------------------------------------------
1026 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
1027 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
1028 Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
1030 B<Note.> The build process for C<perl_> I<does not know> about all the
1031 dependencies, so you should make sure that anything is up-to-date,
1040 =head2 Some C</> became C<\> in pdksh.
1042 You have a very old pdksh. See L<Prerequisites>.
1044 =head2 C<'errno'> - unresolved external
1046 You do not have MT-safe F<db.lib>. See L<Prerequisites>.
1048 =head2 Problems with tr or sed
1050 reported with very old version of tr and sed.
1052 =head2 Some problem (forget which ;-)
1054 You have an older version of F<perl.dll> on your LIBPATH, which
1055 broke the build of extensions.
1057 =head2 Library ... not found
1059 You did not run C<omflibs>. See L<Prerequisites>.
1061 =head2 Segfault in make
1063 You use an old version of GNU make. See L<Prerequisites>.
1065 =head1 Specific (mis)features of OS/2 port
1067 =head2 C<setpriority>, C<getpriority>
1069 Note that these functions are compatible with *nix, not with the older
1070 ports of '94 - 95. The priorities are absolute, go from 32 to -95,
1071 lower is quicker. 0 is the default priority.
1075 Multi-argument form of C<system()> allows an additional numeric
1076 argument. The meaning of this argument is described in
1079 =head2 C<extproc> on the first line
1081 If the first chars of a script are C<"extproc ">, this line is treated
1082 as C<#!>-line, thus all the switches on this line are processed (twice
1083 if script was started via cmd.exe).
1085 =head2 Additional modules:
1087 L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. These
1088 modules provide access to additional numeric argument for C<system>
1089 and to the list of the running processes,
1090 to DLLs having functions with REXX signature and to REXX runtime, to
1091 OS/2 databases in the F<.INI> format, and to Extended Attributes.
1093 Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
1094 C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
1096 =head2 Prebuilt methods:
1100 =item C<File::Copy::syscopy>
1102 used by C<File::Copy::copy>, see L<File::Copy>.
1104 =item C<DynaLoader::mod2fname>
1106 used by C<DynaLoader> for DLL name mangling.
1108 =item C<Cwd::current_drive()>
1112 =item C<Cwd::sys_chdir(name)>
1114 leaves drive as it is.
1116 =item C<Cwd::change_drive(name)>
1119 =item C<Cwd::sys_is_absolute(name)>
1121 means has drive letter and is_rooted.
1123 =item C<Cwd::sys_is_rooted(name)>
1125 means has leading C<[/\\]> (maybe after a drive-letter:).
1127 =item C<Cwd::sys_is_relative(name)>
1129 means changes with current dir.
1131 =item C<Cwd::sys_cwd(name)>
1133 Interface to cwd from EMX. Used by C<Cwd::cwd>.
1135 =item C<Cwd::sys_abspath(name, dir)>
1137 Really really odious function to implement. Returns absolute name of
1138 file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1141 =item C<Cwd::extLibpath([type])
1143 Get current value of extended library search path. If C<type> is
1144 present and I<true>, works with END_LIBPATH, otherwise with
1147 =item C<Cwd::extLibpath_set( path [, type ] )>
1149 Set current value of extended library search path. If C<type> is
1150 present and I<true>, works with END_LIBPATH, otherwise with
1155 (Note that some of these may be moved to different libraries -
1165 Since L<flock(3)> is present in EMX, but is not functional, it is
1166 emulated by perl. To disable the emulations, set environment variable
1167 C<USE_PERL_FLOCK=0>.
1171 Here is the list of things which may be "broken" on
1172 EMX (from EMX docs):
1178 The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not
1183 L<sock_init(3)> is not required and not implemented.
1187 L<flock(3)> is not yet implemented (dummy function). (Perl has a workaround.)
1191 L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1199 waitpid() is not implemented for negative values of PID.
1203 Note that C<kill -9> does not work with the current version of EMX.
1207 Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
1208 of F<sh.exe> plague perl as well.
1210 In particular, uppercase letters do not work in C<[...]>-patterns with
1215 =head2 Modifications
1217 Perl modifies some standard C library calls in the following ways:
1223 C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
1227 is created using C<TMP> or C<TEMP> environment variable, via
1232 If the current directory is not writable, file is created using modified
1233 C<tmpnam>, so there may be a race condition.
1237 a dummy implementation.
1241 C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1245 Since L<flock(3)> is present in EMX, but is not functional, it is
1246 emulated by perl. To disable the emulations, set environment variable
1247 C<USE_PERL_FLOCK=0>.
1253 Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
1254 same basket (though EMX environment tries hard to overcome this
1255 limitations, so the situation may somehow improve). There are 4
1256 executables for Perl provided by the distribution:
1260 The main workhorse. This is a chimera executable: it is compiled as an
1261 C<a.out>-style executable, but is linked with C<omf>-style dynamic
1262 library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1265 It can load perl dynamic extensions, and it can fork(). Unfortunately,
1266 with the current version of EMX it cannot fork() with dynamic
1267 extensions loaded (may be fixed by patches to EMX).
1269 B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1273 This is a statically linked C<a.out>-style executable. It can fork(),
1274 but cannot load dynamic Perl extensions. The supplied executable has a
1275 lot of extensions prebuilt, thus there are situations when it can
1276 perform tasks not possible using F<perl.exe>, like fork()ing when
1277 having some standard extension loaded. This executable is a VIO
1280 B<Note.> A better behaviour could be obtained from C<perl.exe> if it
1281 were statically linked with standard I<Perl extensions>, but
1282 dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
1283 be able to fork() with standard extensions, I<and> would be able to
1284 dynamically load arbitrary extensions. Some changes to Makefiles and
1285 hint files should be necessary to achieve this.
1287 I<This is also the only executable with does not require OS/2.> The
1288 friends locked into C<M$> world would appreciate the fact that this
1289 executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
1290 appropriate extender. See L<"Other OSes">.
1292 =head2 F<perl__.exe>
1294 This is the same executable as F<perl___.exe>, but it is a PM
1297 B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
1298 application are redirected to C<nul>. However, it is possible to see
1299 them if you start C<perl__.exe> from a PM program which emulates a
1300 console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
1301 possible> to use Perl debugger (see L<perldebug>) to debug your PM
1304 This flavor is required if you load extensions which use PM, like
1305 the forthcoming C<Perl/Tk>.
1307 =head2 F<perl___.exe>
1309 This is an C<omf>-style executable which is dynamically linked to
1310 F<perl.dll> and CRT DLL. I know no advantages of this executable
1311 over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1312 that the build process is not so convoluted as with C<perl.exe>.
1314 It is a VIO application.
1316 =head2 Why strange names?
1318 Since Perl processes the C<#!>-line (cf.
1319 L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1320 L<perldiag/"Not a perl script">,
1321 L<perldiag/"No Perl script found in input">), it should know when a
1322 program I<is a Perl>. There is some naming convention which allows
1323 Perl to distinguish correct lines from wrong ones. The above names are
1324 almost the only names allowed by this convention which do not contain
1325 digits (which have absolutely different semantics).
1327 =head2 Why dynamic linking?
1329 Well, having several executables dynamically linked to the same huge
1330 library has its advantages, but this would not substantiate the
1331 additional work to make it compile. The reason is stupid-but-quick
1332 "hard" dynamic linking used by OS/2.
1334 The address tables of DLLs are patched only once, when they are
1335 loaded. The addresses of entry points into DLLs are guaranteed to be
1336 the same for all programs which use the same DLL, which reduces the
1337 amount of runtime patching - once DLL is loaded, its code is
1340 While this allows some performance advantages, this makes life
1341 terrible for developers, since the above scheme makes it impossible
1342 for a DLL to be resolved to a symbol in the .EXE file, since this
1343 would need a DLL to have different relocations tables for the
1344 executables which use it.
1346 However, a Perl extension is forced to use some symbols from the perl
1347 executable, say to know how to find the arguments provided on the perl
1348 internal evaluation stack. The solution is that the main code of
1349 interpreter should be contained in a DLL, and the F<.EXE> file just loads
1350 this DLL into memory and supplies command-arguments.
1352 This I<greatly> increases the load time for the application (as well as
1353 the number of problems during compilation). Since interpreter is in a DLL,
1354 the CRT is basically forced to reside in a DLL as well (otherwise
1355 extensions would not be able to use CRT).
1357 =head2 Why chimera build?
1359 Current EMX environment does not allow DLLs compiled using Unixish
1360 C<a.out> format to export symbols for data. This forces C<omf>-style
1361 compile of F<perl.dll>.
1363 Current EMX environment does not allow F<.EXE> files compiled in
1364 C<omf> format to fork(). fork() is needed for exactly three Perl
1369 =item explicit fork()
1377 opening pipes to itself.
1381 While these operations are not questions of life and death, a lot of
1382 useful scripts use them. This forces C<a.out>-style compile of
1388 Here we list environment variables with are either OS/2- and DOS- and
1389 Win*-specific, or are more important under OS/2 than under other OSes.
1391 =head2 C<PERLLIB_PREFIX>
1393 Specific for EMX port. Should have the form
1401 If the beginning of some prebuilt path matches F<path1>, it is
1402 substituted with F<path2>.
1404 Should be used if the perl library is moved from the default
1405 location in preference to C<PERL(5)LIB>, since this would not leave wrong
1406 entries in @INC. Say, if the compiled version of perl looks for @INC
1407 in F<f:/perllib/lib>, and you want to install the library in
1410 set PERLLIB_PREFIX=f:/perllib/lib;h:/opt/gnu
1412 =head2 C<PERL_BADLANG>
1414 If 1, perl ignores setlocale() failing. May be useful with some
1417 =head2 C<PERL_BADFREE>
1419 If 1, perl would not warn of in case of unwarranted free(). May be
1420 useful in conjunction with the module DB_File, since Berkeley DB
1421 memory handling code is buggy.
1423 =head2 C<PERL_SH_DIR>
1425 Specific for EMX port. Gives the directory part of the location for
1428 =head2 C<USE_PERL_FLOCK>
1430 Specific for EMX port. Since L<flock(3)> is present in EMX, but is not
1431 functional, it is emulated by perl. To disable the emulations, set
1432 environment variable C<USE_PERL_FLOCK=0>.
1434 =head2 C<TMP> or C<TEMP>
1436 Specific for EMX port. Used as storage place for temporary files, most
1437 notably C<-e> scripts.
1441 Here we list major changes which could make you by surprise.
1445 C<setpriority> and C<getpriority> are not compatible with earlier
1446 ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1448 =head2 DLL name mangling
1450 With the release 5.003_01 the dynamically loadable libraries
1451 should be rebuilt. In particular, DLLs are now created with the names
1452 which contain a checksum, thus allowing workaround for OS/2 scheme of
1457 As of release 5.003_01 perl is linked to multithreaded CRT
1458 DLL. If perl itself is not compiled multithread-enabled, so will not be perl
1459 malloc(). However, extensions may use multiple thread on their own
1462 Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
1464 =head2 Calls to external programs
1466 Due to a popular demand the perl external program calling has been
1467 changed wrt Andreas Kaiser's port. I<If> perl needs to call an
1468 external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1469 whatever is the override, see L<"PERL_SH_DIR">.
1471 Thus means that you need to get some copy of a F<sh.exe> as well (I
1472 use one from pdksh). The drive F<F:> above is set up automatically during
1473 the build to a correct value on the builder machine, but is
1474 overridable at runtime,
1476 B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1477 one non-overridable shell per platform. The obvious choices for OS/2
1478 are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
1479 with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
1480 100% compatibility with the scripts coming from *nix. As an added benefit
1481 this works as well under DOS if you use DOS-enabled port of pdksh
1482 (see L<"Prerequisites">).
1484 B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
1485 via fork()/exec(), and there is I<no> functioning exec() on
1486 OS/2. exec() is emulated by EMX by asyncroneous call while the caller
1487 waits for child completion (to pretend that the C<pid> did not change). This
1488 means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1489 which may lead to some resources taken from the system (even if we do
1490 not count extra work needed for fork()ing).
1492 Note that this a lesser issue now when we do not spawn F<sh.exe>
1493 unless needed (metachars found).
1495 One can always start F<cmd.exe> explicitly via
1497 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1499 If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
1500 scripts, the long-term solution proposed on p5-p is to have a directive
1504 which will override system(), exec(), C<``>, and
1505 C<open(,'...|')>. With current perl you may override only system(),
1506 readpipe() - the explicit version of C<``>, and maybe exec(). The code
1507 will substitute the one-argument call to system() by
1508 C<CORE::system('cmd.exe', '/c', shift)>.
1510 If you have some working code for C<OS2::Cmd>, please send it to me,
1511 I will include it into distribution. I have no need for such a module, so
1514 For the details of the current situation with calling external programs,
1515 see L<Starting OS/2 (and DOS) programs under Perl>.
1521 External scripts may be called by name. Perl will try the same extensions
1522 as when processing B<-S> command-line switch.
1526 =head2 Memory allocation
1528 Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
1529 for speed, but perl is not, since its malloc is lightning-fast.
1530 Perl-memory-usage-tuned benchmarks show that Perl's malloc is 5 times quickier
1531 than EMX one. I do not have convincing data about memory footpring, but
1532 a (pretty random) benchmark showed that Perl one is 5% better.
1534 Combination of perl's malloc() and rigid DLL name resolution creates
1535 a special problem with library functions which expect their return value to
1536 be free()d by system's free(). To facilitate extensions which need to call
1537 such functions, system memory-allocation functions are still available with
1538 the prefix C<emx_> added. (Currently only DLL perl has this, it should
1539 propagate to F<perl_.exe> shortly.)
1543 One can build perl with thread support enabled by providing C<-D usethreads>
1544 option to F<Configure>. Currently OS/2 support of threads is very
1547 Most notable problems:
1553 may have a race condition. Needs a reimplementation (in terms of chaining
1554 waiting threads, with linker list stored in per-thread structure?).
1558 has a couple of static variables used in OS/2-specific functions. (Need to be
1559 moved to per-thread structure, or serialized?)
1563 Note that these problems should not discourage experimenting, since they
1564 have a low probability of affecting small programs.
1570 I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
1571 into my ftp directory, mirrored on CPAN. I made
1572 some minor changes needed to compile them by standard tools. I cannot
1573 test UPM and FTP, so I will appreciate your feedback. Other extensions
1574 there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1575 files - and maybe some other extensions at the time you read it.
1577 Note that OS2 perl defines 2 pseudo-extension functions
1578 OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1579 L<Prebuilt methods>).
1581 The -R switch of older perl is deprecated. If you need to call a REXX code
1582 which needs access to variables, include the call into a REXX compartment
1584 REXX_call {...block...};
1586 Two new functions are supported by REXX code,
1588 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1590 If you have some other extensions you want to share, send the code to
1591 me. At least two are available: tied access to EA's, and tied access
1592 to system databases.
1596 Ilya Zakharevich, ilya@math.ohio-state.edu