This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
more VMS patches from Dan Sugalski <sugalskd@osshe.edu>
[perl5.git] / README.os2
CommitLineData
a56dbb1c
PP
1If you read this file _as_is_, just ignore the funny characters you
2see. It is written in the POD format (see perlpod manpage) which is
3specially designed to be readable as is.
4
5=head1 NAME
6
72ea3524 7perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.
a56dbb1c
PP
8
9=head1 SYNOPSIS
10
11One can read this document in the following formats:
12
13 man perlos2
14 view perl perlos2
15 explorer perlos2.html
16 info perlos2
17
18to list some (not all may be available simultaneously), or it may
19be read I<as is>: either as F<README.os2>, or F<pod/perlos2.pod>.
20
72ea3524
IZ
21To read the F<.INF> version of documentation (B<very> recommended)
22outside of OS/2, one needs an IBM's reader (may be available on IBM
df3ef7a9
IZ
23ftp sites (?) (URL anyone?)) or shipped with PC DOS 7.0 and IBM's
24Visual Age C++ 3.5.
25
26A copy of a Win* viewer is contained in the "Just add OS/2 Warp" package
27
28 ftp://ftp.software.ibm.com/ps/products/os2/tools/jaow/jaow.zip
29
aa689395 30in F<?:\JUST_ADD\view.exe>. This gives one an access to EMX's
df3ef7a9 31F<.INF> docs as well (text form is available in F</emx/doc> in
aa689395 32EMX's distribution).
72ea3524 33
d7678ab8
CS
34Note that if you have F<lynx.exe> installed, you can follow WWW links
35from this document in F<.INF> format. If you have EMX docs installed
36correctly, you can follow library links (you need to have C<view emxbook>
37working by setting C<EMXBOOK> environment variable as it is described
38in EMX docs).
39
a56dbb1c
PP
40=cut
41
42Contents
43
df3ef7a9 44 perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.
a56dbb1c 45
df3ef7a9
IZ
46 NAME
47 SYNOPSIS
48 DESCRIPTION
a56dbb1c
PP
49 - Target
50 - Other OSes
51 - Prerequisites
aa689395
PP
52 - Starting Perl programs under OS/2 (and DOS and...)
53 - Starting OS/2 (and DOS) programs under Perl
df3ef7a9 54 Frequently asked questions
72ea3524 55 - I cannot run external programs
df3ef7a9
IZ
56 - I cannot embed perl into my program, or use perl.dll from my program.
57 - `` and pipe-open do not work under DOS.
aa689395 58 - Cannot start find.exe "pattern" file
df3ef7a9 59 INSTALLATION
a56dbb1c
PP
60 - Automatic binary installation
61 - Manual binary installation
62 - Warning
df3ef7a9 63 Accessing documentation
a56dbb1c
PP
64 - OS/2 .INF file
65 - Plain text
66 - Manpages
67 - HTML
68 - GNU info files
69 - .PDF files
70 - LaTeX docs
df3ef7a9 71 BUILD
a56dbb1c
PP
72 - Prerequisites
73 - Getting perl source
74 - Application of the patches
75 - Hand-editing
76 - Making
77 - Testing
78 - Installing the built perl
79 - a.out-style build
df3ef7a9 80 Build FAQ
a56dbb1c
PP
81 - Some / became \ in pdksh.
82 - 'errno' - unresolved external
83 - Problems with tr
84 - Some problem (forget which ;-)
85 - Library ... not found
df3ef7a9 86 - Segfault in make
aa689395 87 Specific (mis)features of EMX port
a56dbb1c
PP
88 - setpriority, getpriority
89 - system()
aa689395 90 - extproc on the first line
a56dbb1c
PP
91 - Additional modules:
92 - Prebuilt methods:
93 - Misfeatures
df3ef7a9
IZ
94 - Modifications
95 Perl flavors
a56dbb1c
PP
96 - perl.exe
97 - perl_.exe
98 - perl__.exe
99 - perl___.exe
100 - Why strange names?
101 - Why dynamic linking?
102 - Why chimera build?
df3ef7a9 103 ENVIRONMENT
a56dbb1c
PP
104 - PERLLIB_PREFIX
105 - PERL_BADLANG
106 - PERL_BADFREE
107 - PERL_SH_DIR
108 - TMP or TEMP
df3ef7a9 109 Evolution
a56dbb1c 110 - Priorities
72ea3524 111 - DLL name mangling
a56dbb1c
PP
112 - Threading
113 - Calls to external programs
df3ef7a9
IZ
114 - Memory allocation
115 AUTHOR
116 SEE ALSO
117
a56dbb1c
PP
118=head1 DESCRIPTION
119
120=head2 Target
121
122The target is to make OS/2 the best supported platform for
72ea3524 123using/building/developing Perl and I<Perl applications>, as well as
aa689395
PP
124make Perl the best language to use under OS/2. The secondary target is
125to try to make this work under DOS and Win* as well (but not B<too> hard).
a56dbb1c
PP
126
127The current state is quite close to this target. Known limitations:
128
129=over 5
130
131=item *
132
133Some *nix programs use fork() a lot, but currently fork() is not
134supported after I<use>ing dynamically loaded extensions.
135
136=item *
137
138You need a separate perl executable F<perl__.exe> (see L<perl__.exe>)
139to use PM code in your application (like the forthcoming Perl/Tk).
140
141=item *
142
aa689395 143There is no simple way to access WPS objects. The only way I know
a56dbb1c 144is via C<OS2::REXX> extension (see L<OS2::REXX>), and we do not have access to
aa689395
PP
145convenience methods of Object-REXX. (Is it possible at all? I know
146of no Object-REXX API.)
a56dbb1c
PP
147
148=back
149
150Please keep this list up-to-date by informing me about other items.
151
152=head2 Other OSes
153
aa689395 154Since OS/2 port of perl uses a remarkable EMX environment, it can
a56dbb1c
PP
155run (and build extensions, and - possibly - be build itself) under any
156environment which can run EMX. The current list is DOS,
72ea3524 157DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors,
a56dbb1c
PP
158only one works, see L<"perl_.exe">.
159
160Note that not all features of Perl are available under these
161environments. This depends on the features the I<extender> - most
aa689395 162probably RSX - decided to implement.
a56dbb1c
PP
163
164Cf. L<Prerequisites>.
165
166=head2 Prerequisites
167
168=over 6
169
aa689395 170=item EMX
a56dbb1c 171
aa689395 172EMX runtime is required (may be substituted by RSX). Note that
55497cff 173it is possible to make F<perl_.exe> to run under DOS without any
72ea3524 174external support by binding F<emx.exe>/F<rsx.exe> to it, see L<emxbind>. Note
aa689395 175that under DOS for best results one should use RSX runtime, which
55497cff 176has much more functions working (like C<fork>, C<popen> and so on). In
aa689395
PP
177fact RSX is required if there is no VCPI present. Note the
178RSX requires DPMI.
a56dbb1c 179
aa689395
PP
180Only the latest runtime is supported, currently C<0.9c>. Perl may run
181under earlier versions of EMX, but this is not tested.
a56dbb1c 182
aa689395 183One can get different parts of EMX from, say
a56dbb1c 184
d7678ab8
CS
185 ftp://ftp.cdrom.com/pub/os2/emx09c/
186 ftp://hobbes.nmsu.edu/os2/unix/emx09c/
a56dbb1c
PP
187
188The runtime component should have the name F<emxrt.zip>.
189
72ea3524
IZ
190B<NOTE>. It is enough to have F<emx.exe>/F<rsx.exe> on your path. One
191does not need to specify them explicitly (though this
192
193 emx perl_.exe -de 0
194
195will work as well.)
196
aa689395 197=item RSX
a56dbb1c 198
aa689395 199To run Perl on DPMI platforms one needs RSX runtime. This is
72ea3524 200needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see
aa689395
PP
201L<"Other OSes">). RSX would not work with VCPI
202only, as EMX would, it requires DMPI.
55497cff 203
aa689395 204Having RSX and the latest F<sh.exe> one gets a fully functional
55497cff
PP
205B<*nix>-ish environment under DOS, say, C<fork>, C<``> and
206pipe-C<open> work. In fact, MakeMaker works (for static build), so one
207can have Perl development environment under DOS.
a56dbb1c 208
aa689395 209One can get RSX from, say
a56dbb1c 210
d7678ab8 211 ftp://ftp.cdrom.com/pub/os2/emx09c/contrib
a56dbb1c 212 ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc
d7678ab8 213 ftp://ftp.leo.org/pub/comp/os/os2/leo/devtools/emx+gcc/contrib
a56dbb1c
PP
214
215Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
216
55497cff
PP
217The latest F<sh.exe> with DOS hooks is available at
218
d7678ab8 219 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
55497cff 220
aa689395 221=item HPFS
a56dbb1c
PP
222
223Perl does not care about file systems, but to install the whole perl
224library intact one needs a file system which supports long file names.
225
226Note that if you do not plan to build the perl itself, it may be
aa689395
PP
227possible to fool EMX to truncate file names. This is not supported,
228read EMX docs to see how to do it.
229
230=item pdksh
231
232To start external programs with complicated command lines (like with
233pipes in between, and/or quoting of arguments), Perl uses an external
234shell. With EMX port such shell should be named <sh.exe>, and located
235either in the wired-in-during-compile locations (usually F<F:/bin>),
236or in configurable location (see L<"PERL_SH_DIR">).
237
238For best results use EMX pdksh. The soon-to-be-available standard
239binary (5.2.12?) runs under DOS (with L<RSX>) as well, meanwhile use
240the binary from
241
d7678ab8 242 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
a56dbb1c
PP
243
244=back
245
aa689395 246=head2 Starting Perl programs under OS/2 (and DOS and...)
a56dbb1c
PP
247
248Start your Perl program F<foo.pl> with arguments C<arg1 arg2 arg3> the
249same way as on any other platform, by
250
251 perl foo.pl arg1 arg2 arg3
252
253If you want to specify perl options C<-my_opts> to the perl itself (as
254opposed to to your program), use
255
256 perl -my_opts foo.pl arg1 arg2 arg3
257
aa689395 258Alternately, if you use OS/2-ish shell, like CMD or 4os2, put
a56dbb1c
PP
259the following at the start of your perl script:
260
aa689395 261 extproc perl -S -my_opts
a56dbb1c
PP
262
263rename your program to F<foo.cmd>, and start it by typing
264
265 foo arg1 arg2 arg3
266
a56dbb1c
PP
267Note that because of stupid OS/2 limitations the full path of the perl
268script is not available when you use C<extproc>, thus you are forced to
269use C<-S> perl switch, and your script should be on path. As a plus
270side, if you know a full path to your script, you may still start it
271with
272
aa689395 273 perl ../../blah/foo.cmd arg1 arg2 arg3
a56dbb1c 274
aa689395
PP
275(note that the argument C<-my_opts> is taken care of by the C<extproc> line
276in your script, see L<C<extproc> on the first line>).
a56dbb1c
PP
277
278To understand what the above I<magic> does, read perl docs about C<-S>
aa689395 279switch - see L<perlrun>, and cmdref about C<extproc>:
a56dbb1c
PP
280
281 view perl perlrun
282 man perlrun
283 view cmdref extproc
284 help extproc
285
286or whatever method you prefer.
287
72ea3524 288There are also endless possibilities to use I<executable extensions> of
aa689395 2894os2, I<associations> of WPS and so on... However, if you use
a56dbb1c 290*nixish shell (like F<sh.exe> supplied in the binary distribution),
72ea3524 291you need to follow the syntax specified in L<perlrun/"Switches">.
a56dbb1c 292
d8c2d278
IZ
293Note that B<-S> switch enables a search with additional extensions
294F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well.
295
aa689395 296=head2 Starting OS/2 (and DOS) programs under Perl
a56dbb1c
PP
297
298This is what system() (see L<perlfunc/system>), C<``> (see
299L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
300are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
301do).
302
303Note however that to use some of these operators you need to have a
aa689395 304sh-syntax shell installed (see L<"Pdksh">,
a56dbb1c
PP
305L<"Frequently asked questions">), and perl should be able to find it
306(see L<"PERL_SH_DIR">).
307
308The only cases when the shell is not used is the multi-argument
309system() (see L<perlfunc/system>)/exec() (see L<perlfunc/exec>), and
310one-argument version thereof without redirection and shell
491527d0
GS
311meta-characters. Perl may also start scripts which start with cookies
312C<extproc> or C<#!> directly, without an intervention of shell.
313
314If starting scripts directly, Perl will use exactly the same algorithm as for
315the search of script given by B<-S> command-line option: it will look in
316the current directory, then on components of C<$ENV{PATH}> using the
317following order of appended extensions: no extension, F<.cmd>, F<.btm>,
318F<.bat>, F<.pl>.
319
320Note that Perl will start to look for scripts only if OS/2 cannot start the
321specified application, thus C<system 'blah'> will not look for a script if
322there is an executable file F<blah.exe> I<anywhere> on C<PATH>.
323
324Note also that executable files on OS/2 can have an arbitrary extension,
325but F<.exe> will be automatically appended if no dot is present in the name.
326The workaround as as simple as that: since F<blah.> and F<blah> denote the
327same file, to start an executable residing in file F<n:/bin/blah> (no
328extension) give an argument C<n:/bin/blah.> to system().
329
330The last note is that currently it is not straightforward to start PM
331programs from VIO (=text-mode) Perl process and visa versa. Either ensure
332that shell will be used, as in C<system 'cmd /c epm'>, or start it using
333optional arguments to system() documented in C<OS2::Process> module. This
334is considered a bug and should be fixed soon.
335
a56dbb1c
PP
336
337=head1 Frequently asked questions
338
72ea3524 339=head2 I cannot run external programs
a56dbb1c 340
55497cff
PP
341=over 4
342
343=item
344
a56dbb1c 345Did you run your programs with C<-w> switch? See
aa689395 346L<Starting OS/2 (and DOS) programs under Perl>.
a56dbb1c 347
55497cff
PP
348=item
349
350Do you try to run I<internal> shell commands, like C<`copy a b`>
351(internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
72ea3524 352need to specify your shell explicitly, like C<`cmd /c copy a b`>,
55497cff
PP
353since Perl cannot deduce which commands are internal to your shell.
354
355=back
356
a56dbb1c
PP
357=head2 I cannot embed perl into my program, or use F<perl.dll> from my
358program.
359
360=over 4
361
aa689395 362=item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
a56dbb1c
PP
363
364If not, you need to build a stand-alone DLL for perl. Contact me, I
365did it once. Sockets would not work, as a lot of other stuff.
366
aa689395 367=item Did you use L<ExtUtils::Embed>?
a56dbb1c
PP
368
369I had reports it does not work. Somebody would need to fix it.
370
371=back
372
55497cff
PP
373=head2 C<``> and pipe-C<open> do not work under DOS.
374
72ea3524 375This may a variant of just L<"I cannot run external programs">, or a
aa689395 376deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
72ea3524 377for these commands to work, and you may need a port of F<sh.exe> which
55497cff 378understands command arguments. One of such ports is listed in
aa689395
PP
379L<"Prerequisites"> under RSX. Do not forget to set variable
380C<L<"PERL_SH_DIR">> as well.
381
382DPMI is required for RSX.
383
384=head2 Cannot start C<find.exe "pattern" file>
55497cff 385
aa689395
PP
386Use one of
387
388 system 'cmd', '/c', 'find "pattern" file';
389 `cmd /c 'find "pattern" file'`
390
391This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
392C<perl.exe>, but this is a price to pay if you want to use
393non-conforming program. In fact F<find.exe> cannot be started at all
394using C library API only. Otherwise the following command-lines were
395equivalent:
396
397 find "pattern" file
398 find pattern file
55497cff 399
a56dbb1c
PP
400=head1 INSTALLATION
401
402=head2 Automatic binary installation
403
72ea3524 404The most convenient way of installing perl is via perl installer
a56dbb1c
PP
405F<install.exe>. Just follow the instructions, and 99% of the
406installation blues would go away.
407
408Note however, that you need to have F<unzip.exe> on your path, and
aa689395
PP
409EMX environment I<running>. The latter means that if you just
410installed EMX, and made all the needed changes to F<Config.sys>,
411you may need to reboot in between. Check EMX runtime by running
a56dbb1c
PP
412
413 emxrev
414
415A folder is created on your desktop which contains some useful
416objects.
417
418B<Things not taken care of by automatic binary installation:>
419
420=over 15
421
422=item C<PERL_BADLANG>
423
424may be needed if you change your codepage I<after> perl installation,
aa689395 425and the new value is not supported by EMX. See L<"PERL_BADLANG">.
a56dbb1c
PP
426
427=item C<PERL_BADFREE>
428
429see L<"PERL_BADFREE">.
430
431=item F<Config.pm>
432
433This file resides somewhere deep in the location you installed your
434perl library, find it out by
435
436 perl -MConfig -le "print $INC{'Config.pm'}"
437
438While most important values in this file I<are> updated by the binary
439installer, some of them may need to be hand-edited. I know no such
440data, please keep me informed if you find one.
441
442=back
443
aa689395
PP
444B<NOTE>. Because of a typo the binary installer of 5.00305
445would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
446remove this variable and put C<L<PERL_SH_DIR>> instead.
447
a56dbb1c
PP
448=head2 Manual binary installation
449
72ea3524 450As of version 5.00305, OS/2 perl binary distribution comes split
a56dbb1c 451into 11 components. Unfortunately, to enable configurable binary
aa689395 452installation, the file paths in the zip files are not absolute, but
a56dbb1c
PP
453relative to some directory.
454
455Note that the extraction with the stored paths is still necessary
aa689395 456(default with unzip, specify C<-d> to pkunzip). However, you
a56dbb1c
PP
457need to know where to extract the files. You need also to manually
458change entries in F<Config.sys> to reflect where did you put the
72ea3524 459files. Note that if you have some primitive unzipper (like
aa689395 460pkunzip), you may get a lot of warnings/errors during
72ea3524 461unzipping. Upgrade to C<(w)unzip>.
a56dbb1c
PP
462
463Below is the sample of what to do to reproduce the configuration on my
464machine:
465
466=over 3
467
468=item Perl VIO and PM executables (dynamically linked)
469
470 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
471 unzip perl_exc.zip *.dll -d f:/emx.add/dll
472
aa689395
PP
473(have the directories with C<*.exe> on PATH, and C<*.dll> on
474LIBPATH);
a56dbb1c
PP
475
476=item Perl_ VIO executable (statically linked)
477
478 unzip perl_aou.zip -d f:/emx.add/bin
479
aa689395 480(have the directory on PATH);
a56dbb1c
PP
481
482=item Executables for Perl utilities
483
484 unzip perl_utl.zip -d f:/emx.add/bin
485
aa689395 486(have the directory on PATH);
a56dbb1c
PP
487
488=item Main Perl library
489
490 unzip perl_mlb.zip -d f:/perllib/lib
491
492If this directory is preserved, you do not need to change
493anything. However, for perl to find it if it is changed, you need to
494C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
495
496=item Additional Perl modules
497
498 unzip perl_ste.zip -d f:/perllib/lib/site_perl
499
500If you do not change this directory, do nothing. Otherwise put this
501directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
502variable. Do not use C<PERL5LIB> unless you have it set already. See
503L<perl/"ENVIRONMENT">.
504
505=item Tools to compile Perl modules
506
507 unzip perl_blb.zip -d f:/perllib/lib
508
509If this directory is preserved, you do not need to change
510anything. However, for perl to find it if it is changed, you need to
511C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
512
513=item Manpages for Perl and utilities
514
515 unzip perl_man.zip -d f:/perllib/man
516
517This directory should better be on C<MANPATH>. You need to have a
aa689395 518working man to access these files.
a56dbb1c
PP
519
520=item Manpages for Perl modules
521
522 unzip perl_mam.zip -d f:/perllib/man
523
524This directory should better be on C<MANPATH>. You need to have a
aa689395 525working man to access these files.
a56dbb1c
PP
526
527=item Source for Perl documentation
528
529 unzip perl_pod.zip -d f:/perllib/lib
530
531This is used by by C<perldoc> program (see L<perldoc>), and may be used to
aa689395 532generate HTML documentation usable by WWW browsers, and
a56dbb1c
PP
533documentation in zillions of other formats: C<info>, C<LaTeX>,
534C<Acrobat>, C<FrameMaker> and so on.
535
aa689395 536=item Perl manual in F<.INF> format
a56dbb1c
PP
537
538 unzip perl_inf.zip -d d:/os2/book
539
540This directory should better be on C<BOOKSHELF>.
541
542=item Pdksh
543
544 unzip perl_sh.zip -d f:/bin
545
72ea3524 546This is used by perl to run external commands which explicitly
a56dbb1c
PP
547require shell, like the commands using I<redirection> and I<shell
548metacharacters>. It is also used instead of explicit F</bin/sh>.
549
550Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
551the above location.
552
aa689395 553B<Note.> It may be possible to use some other sh-compatible shell
a56dbb1c
PP
554(I<not tested>).
555
556=back
557
558After you installed the components you needed and updated the
559F<Config.sys> correspondingly, you need to hand-edit
560F<Config.pm>. This file resides somewhere deep in the location you
561installed your perl library, find it out by
562
563 perl -MConfig -le "print $INC{'Config.pm'}"
564
565You need to correct all the entries which look like file paths (they
566currently start with C<f:/>).
567
568=head2 B<Warning>
569
570The automatic and manual perl installation leave precompiled paths
571inside perl executables. While these paths are overwriteable (see
572L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
573binary editing of paths inside the executables/DLLs.
574
575=head1 Accessing documentation
576
577Depending on how you built/installed perl you may have (otherwise
578identical) Perl documentation in the following formats:
579
580=head2 OS/2 F<.INF> file
581
aa689395 582Most probably the most convenient form. Under OS/2 view it as
a56dbb1c
PP
583
584 view perl
585 view perl perlfunc
586 view perl less
587 view perl ExtUtils::MakeMaker
588
589(currently the last two may hit a wrong location, but this may improve
aa689395 590soon). Under Win* see L<"SYNOPSIS">.
a56dbb1c
PP
591
592If you want to build the docs yourself, and have I<OS/2 toolkit>, run
593
594 pod2ipf > perl.ipf
595
596in F</perllib/lib/pod> directory, then
597
598 ipfc /inf perl.ipf
599
600(Expect a lot of errors during the both steps.) Now move it on your
601BOOKSHELF path.
602
603=head2 Plain text
604
605If you have perl documentation in the source form, perl utilities
aa689395 606installed, and GNU groff installed, you may use
a56dbb1c
PP
607
608 perldoc perlfunc
609 perldoc less
610 perldoc ExtUtils::MakeMaker
611
72ea3524 612to access the perl documentation in the text form (note that you may get
a56dbb1c
PP
613better results using perl manpages).
614
615Alternately, try running pod2text on F<.pod> files.
616
617=head2 Manpages
618
aa689395 619If you have man installed on your system, and you installed perl
a56dbb1c 620manpages, use something like this:
5243f9ae 621
5243f9ae
PP
622 man perlfunc
623 man 3 less
624 man ExtUtils.MakeMaker
5243f9ae 625
a56dbb1c
PP
626to access documentation for different components of Perl. Start with
627
628 man perl
629
630Note that dot (F<.>) is used as a package separator for documentation
631for packages, and as usual, sometimes you need to give the section - C<3>
632above - to avoid shadowing by the I<less(1) manpage>.
633
634Make sure that the directory B<above> the directory with manpages is
635on our C<MANPATH>, like this
636
637 set MANPATH=c:/man;f:/perllib/man
638
aa689395 639=head2 HTML
a56dbb1c
PP
640
641If you have some WWW browser available, installed the Perl
642documentation in the source form, and Perl utilities, you can build
aa689395 643HTML docs. Cd to directory with F<.pod> files, and do like this
a56dbb1c
PP
644
645 cd f:/perllib/lib/pod
5243f9ae 646 pod2html
5243f9ae 647
a56dbb1c
PP
648After this you can direct your browser the file F<perl.html> in this
649directory, and go ahead with reading docs, like this:
5243f9ae 650
a56dbb1c 651 explore file:///f:/perllib/lib/pod/perl.html
5243f9ae 652
aa689395 653Alternatively you may be able to get these docs prebuilt from CPAN.
5243f9ae 654
aa689395 655=head2 GNU C<info> files
bb14ff96 656
aa689395 657Users of Emacs would appreciate it very much, especially with
a56dbb1c
PP
658C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
659or, alternately, prebuilt info pages.
615d1a09 660
a56dbb1c
PP
661=head2 F<.PDF> files
662
663for C<Acrobat> are available on CPAN (for slightly old version of
664perl).
665
666=head2 C<LaTeX> docs
667
668can be constructed using C<pod2latex>.
669
670=head1 BUILD
671
672Here we discuss how to build Perl under OS/2. There is an alternative
673(but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
674
675=head2 Prerequisites
676
aa689395
PP
677You need to have the latest EMX development environment, the full
678GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
a56dbb1c
PP
679earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
680check use
681
682 find --version
683 sort --version
684
685). You need the latest version of F<pdksh> installed as F<sh.exe>.
686
687Possible locations to get this from are
688
d7678ab8 689 ftp://hobbes.nmsu.edu/os2/unix/
a56dbb1c
PP
690 ftp://ftp.cdrom.com/pub/os2/unix/
691 ftp://ftp.cdrom.com/pub/os2/dev32/
d7678ab8 692 ftp://ftp.cdrom.com/pub/os2/emx09c/
a56dbb1c 693
eb447b86
IZ
694It is reported that the following archives contain enough utils to
695build perl: gnufutil.zip, gnusutil.zip, gnututil.zip, gnused.zip,
696gnupatch.zip, gnuawk.zip, gnumake.zip and ksh527rt.zip. Note that
697all these utilities are known to be available from LEO:
698
699 ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu
a56dbb1c
PP
700
701Make sure that no copies or perl are currently running. Later steps
702of the build may fail since an older version of perl.dll loaded into
703memory may be found.
704
705Also make sure that you have F</tmp> directory on the current drive,
706and F<.> directory in your C<LIBPATH>. One may try to correct the
707latter condition by
708
709 set BEGINLIBPATH .
710
711if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
712
aa689395 713Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
a56dbb1c
PP
714script in F</emx/lib> directory.
715
aa689395 716Check that you have link386 installed. It comes standard with OS/2,
a56dbb1c
PP
717but may be not installed due to customization. If typing
718
719 link386
720
721shows you do not have it, do I<Selective install>, and choose C<Link
72ea3524 722object modules> in I<Optional system utilities/More>. If you get into
aa689395 723link386, press C<Ctrl-C>.
a56dbb1c
PP
724
725=head2 Getting perl source
726
72ea3524 727You need to fetch the latest perl source (including developers
a56dbb1c
PP
728releases). With some probability it is located in
729
730 http://www.perl.com/CPAN/src/5.0
731 http://www.perl.com/CPAN/src/5.0/unsupported
732
733If not, you may need to dig in the indices to find it in the directory
734of the current maintainer.
735
72ea3524 736Quick cycle of developers release may break the OS/2 build time to
a56dbb1c
PP
737time, looking into
738
739 http://www.perl.com/CPAN/ports/os2/ilyaz/
740
741may indicate the latest release which was publicly released by the
742maintainer. Note that the release may include some additional patches
743to apply to the current source of perl.
744
745Extract it like this
746
747 tar vzxf perl5.00409.tar.gz
748
749You may see a message about errors while extracting F<Configure>. This is
750because there is a conflict with a similarly-named file F<configure>.
751
a56dbb1c
PP
752Change to the directory of extraction.
753
754=head2 Application of the patches
755
756You need to apply the patches in F<./os2/diff.*> and
757F<./os2/POSIX.mkfifo> like this:
758
759 gnupatch -p0 < os2\POSIX.mkfifo
df3ef7a9 760 gnupatch -p0 < os2\diff.configure
a56dbb1c
PP
761
762You may also need to apply the patches supplied with the binary
763distribution of perl.
764
aa689395 765Note also that the F<db.lib> and F<db.a> from the EMX distribution
a56dbb1c 766are not suitable for multi-threaded compile (note that currently perl
aa689395
PP
767is not multithread-safe, but is compiled as multithreaded for
768compatibility with XFree86-OS/2). Get a corrected one from
a56dbb1c
PP
769
770 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
771
772=head2 Hand-editing
773
774You may look into the file F<./hints/os2.sh> and correct anything
775wrong you find there. I do not expect it is needed anywhere.
615d1a09 776
a56dbb1c 777=head2 Making
615d1a09 778
a56dbb1c 779 sh Configure -des -D prefix=f:/perllib
615d1a09 780
aa689395 781C<prefix> means: where to install the resulting perl library. Giving
a56dbb1c
PP
782correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
783see L<"PERLLIB_PREFIX">.
5243f9ae 784
a56dbb1c 785I<Ignore the message about missing C<ln>, and about C<-c> option to
aa689395 786tr>. In fact if you can trace where the latter spurious warning
a56dbb1c 787comes from, please inform me.
615d1a09 788
a56dbb1c 789Now
5243f9ae 790
a56dbb1c 791 make
5243f9ae 792
a56dbb1c
PP
793At some moment the built may die, reporting a I<version mismatch> or
794I<unable to run F<perl>>. This means that most of the build has been
795finished, and it is the time to move the constructed F<perl.dll> to
aa689395
PP
796some I<absolute> location in LIBPATH. After this is done the build
797should finish without a lot of fuss. I<One can avoid the interruption
798if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
799probably this is not needed anymore, since F<miniperl.exe> is linked
800statically now.>
615d1a09 801
a56dbb1c
PP
802Warnings which are safe to ignore: I<mkfifo() redefined> inside
803F<POSIX.c>.
615d1a09 804
a56dbb1c
PP
805=head2 Testing
806
491527d0
GS
807If you haven't yet moved perl.dll onto LIBPATH, do it now(alternatively, if
808you have a previous perl installation you'd rather not disrupt until this one
809is installed, copy perl.dll to the t directory).
810
a56dbb1c
PP
811Now run
812
813 make test
814
72ea3524 815Some tests (4..6) should fail. Some perl invocations should end in a
a56dbb1c
PP
816segfault (system error C<SYS3175>). To get finer error reports,
817
818 cd t
aa689395 819 perl harness
a56dbb1c
PP
820
821The report you get may look like
822
823 Failed Test Status Wstat Total Fail Failed List of failed
824 ---------------------------------------------------------------
825 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
826 lib/io_pipe.t 3 768 6 ?? % ??
827 lib/io_sock.t 3 768 5 ?? % ??
828 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
72ea3524 829 Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
a56dbb1c
PP
830
831Note that using `make test' target two more tests may fail: C<op/exec:1>
aa689395 832because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
55497cff
PP
833that the buffers are not flushed on C<_exit> (this is a bug in the test
834which assumes that tty output is buffered).
a56dbb1c 835
aa689395 836I submitted a patch to EMX which makes it possible to fork() with EMX
72ea3524
IZ
837dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
838that soon the number of failing tests may decrease yet more.
839
df3ef7a9
IZ
840However, the test F<lib/io_udp.t> is disabled, since it never terminates, I
841do not know why. Comments/fixes welcome.
72ea3524 842
a56dbb1c
PP
843The reasons for failed tests are:
844
845=over 8
846
847=item F<io/fs.t>
848
849Checks I<file system> operations. Tests:
850
851=over 10
852
853=item 2-5, 7-11
854
855Check C<link()> and C<inode count> - nonesuch under OS/2.
856
857=item 18
858
859Checks C<atime> and C<mtime> of C<stat()> - I could not understand this test.
860
861=item 25
862
863Checks C<truncate()> on a filehandle just opened for write - I do not
864know why this should or should not work.
865
866=back
867
868=item F<lib/io_pipe.t>
869
aa689395 870Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
a56dbb1c
PP
871dynamic extension loaded - unsupported now.
872
873=item F<lib/io_sock.t>
874
aa689395 875Checks C<IO::Socket> module. Some feature of EMX - test fork()s
a56dbb1c
PP
876with dynamic extension loaded - unsupported now.
877
878=item F<op/stat.t>
879
880Checks C<stat()>. Tests:
881
882=over 4
883
884=item 3
885
886Checks C<inode count> - nonesuch under OS/2.
887
888=item 4
889
890Checks C<mtime> and C<ctime> of C<stat()> - I could not understand this test.
891
892=item 20
893
894Checks C<-x> - determined by the file extension only under OS/2.
895
896=item 35
897
898Needs F</usr/bin>.
899
900=item 39
901
902Checks C<-t> of F</dev/null>. Should not fail!
903
904=back
905
906=back
907
908In addition to errors, you should get a lot of warnings.
909
910=over 4
911
912=item A lot of `bad free'
913
914in databases related to Berkeley DB. This is a confirmed bug of
915DB. You may disable this warnings, see L<"PERL_BADFREE">.
916
917=item Process terminated by SIGTERM/SIGINT
918
919This is a standard message issued by OS/2 applications. *nix
920applications die in silence. It is considered a feature. One can
921easily disable this by appropriate sighandlers.
922
923However the test engine bleeds these message to screen in unexpected
924moments. Two messages of this kind I<should> be present during
925testing.
926
927=item F<*/sh.exe>: ln: not found
928
929=item C<ls>: /dev: No such file or directory
930
931The last two should be self-explanatory. The test suite discovers that
932the system it runs on is not I<that much> *nixish.
933
934=back
615d1a09
PP
935
936A lot of `bad free'... in databases, bug in DB confirmed on other
5243f9ae 937platforms. You may disable it by setting PERL_BADFREE environment variable
a56dbb1c 938to 1.
615d1a09 939
a56dbb1c 940=head2 Installing the built perl
615d1a09 941
491527d0
GS
942If you haven't yet moved perl.dll onto LIBPATH, do it now.
943
a56dbb1c 944Run
615d1a09 945
a56dbb1c 946 make install
615d1a09 947
a56dbb1c
PP
948It would put the generated files into needed locations. Manually put
949F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
aa689395 950PATH, F<perl.dll> to a location on your LIBPATH.
615d1a09 951
a56dbb1c 952Run
615d1a09 953
a56dbb1c 954 make cmdscripts INSTALLCMDDIR=d:/ir/on/path
615d1a09 955
a56dbb1c 956to convert perl utilities to F<.cmd> files and put them on
aa689395 957PATH. You need to put F<.EXE>-utilities on path manually. They are
a56dbb1c
PP
958installed in C<$prefix/bin>, here C<$prefix> is what you gave to
959F<Configure>, see L<Making>.
960
961=head2 C<a.out>-style build
962
963Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
964
965 make perl_
966
967test and install by
968
969 make aout_test
970 make aout_install
971
aa689395 972Manually put F<perl_.exe> to a location on your PATH.
a56dbb1c
PP
973
974Since C<perl_> has the extensions prebuilt, it does not suffer from
72ea3524 975the I<dynamic extensions + fork()> syndrome, thus the failing tests
a56dbb1c
PP
976look like
977
978 Failed Test Status Wstat Total Fail Failed List of failed
979 ---------------------------------------------------------------
980 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
981 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
982 Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
983
984B<Note.> The build process for C<perl_> I<does not know> about all the
985dependencies, so you should make sure that anything is up-to-date,
986say, by doing
987
988 make perl.dll
989
990first.
991
992=head1 Build FAQ
993
994=head2 Some C</> became C<\> in pdksh.
995
996You have a very old pdksh. See L<Prerequisites>.
997
998=head2 C<'errno'> - unresolved external
999
1000You do not have MT-safe F<db.lib>. See L<Prerequisites>.
1001
aa689395 1002=head2 Problems with tr
a56dbb1c 1003
aa689395 1004reported with very old version of tr.
a56dbb1c
PP
1005
1006=head2 Some problem (forget which ;-)
1007
aa689395 1008You have an older version of F<perl.dll> on your LIBPATH, which
a56dbb1c
PP
1009broke the build of extensions.
1010
1011=head2 Library ... not found
1012
1013You did not run C<omflibs>. See L<Prerequisites>.
1014
1015=head2 Segfault in make
1016
aa689395 1017You use an old version of GNU make. See L<Prerequisites>.
a56dbb1c
PP
1018
1019=head1 Specific (mis)features of OS/2 port
1020
1021=head2 C<setpriority>, C<getpriority>
1022
1023Note that these functions are compatible with *nix, not with the older
1024ports of '94 - 95. The priorities are absolute, go from 32 to -95,
72ea3524 1025lower is quicker. 0 is the default priority.
a56dbb1c
PP
1026
1027=head2 C<system()>
1028
1029Multi-argument form of C<system()> allows an additional numeric
1030argument. The meaning of this argument is described in
1031L<OS2::Process>.
1032
aa689395
PP
1033=head2 C<extproc> on the first line
1034
1035If the first chars of a script are C<"extproc ">, this line is treated
1036as C<#!>-line, thus all the switches on this line are processed (twice
1037if script was started via cmd.exe).
1038
a56dbb1c 1039=head2 Additional modules:
615d1a09 1040
a56dbb1c
PP
1041L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. This
1042modules provide access to additional numeric argument for C<system>,
1043to DLLs having functions with REXX signature and to REXX runtime, to
1044OS/2 databases in the F<.INI> format, and to Extended Attributes.
615d1a09 1045
72ea3524 1046Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
a56dbb1c 1047C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
615d1a09 1048
a56dbb1c 1049=head2 Prebuilt methods:
615d1a09 1050
a56dbb1c 1051=over 4
615d1a09 1052
a56dbb1c 1053=item C<File::Copy::syscopy>
615d1a09 1054
d7678ab8 1055used by C<File::Copy::copy>, see L<File::Copy>.
615d1a09 1056
a56dbb1c 1057=item C<DynaLoader::mod2fname>
615d1a09 1058
72ea3524 1059used by C<DynaLoader> for DLL name mangling.
615d1a09 1060
a56dbb1c 1061=item C<Cwd::current_drive()>
615d1a09 1062
a56dbb1c 1063Self explanatory.
615d1a09 1064
a56dbb1c 1065=item C<Cwd::sys_chdir(name)>
615d1a09 1066
a56dbb1c 1067leaves drive as it is.
615d1a09 1068
a56dbb1c 1069=item C<Cwd::change_drive(name)>
615d1a09 1070
615d1a09 1071
a56dbb1c 1072=item C<Cwd::sys_is_absolute(name)>
615d1a09 1073
a56dbb1c 1074means has drive letter and is_rooted.
615d1a09 1075
a56dbb1c 1076=item C<Cwd::sys_is_rooted(name)>
615d1a09 1077
a56dbb1c 1078means has leading C<[/\\]> (maybe after a drive-letter:).
615d1a09 1079
a56dbb1c 1080=item C<Cwd::sys_is_relative(name)>
615d1a09 1081
a56dbb1c 1082means changes with current dir.
615d1a09 1083
a56dbb1c 1084=item C<Cwd::sys_cwd(name)>
615d1a09 1085
aa689395 1086Interface to cwd from EMX. Used by C<Cwd::cwd>.
615d1a09 1087
a56dbb1c 1088=item C<Cwd::sys_abspath(name, dir)>
615d1a09 1089
a56dbb1c
PP
1090Really really odious function to implement. Returns absolute name of
1091file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1092current dir.
615d1a09 1093
a56dbb1c 1094=item C<Cwd::extLibpath([type])
615d1a09 1095
a56dbb1c
PP
1096Get current value of extended library search path. If C<type> is
1097present and I<true>, works with END_LIBPATH, otherwise with
1098C<BEGIN_LIBPATH>.
615d1a09 1099
a56dbb1c 1100=item C<Cwd::extLibpath_set( path [, type ] )>
615d1a09 1101
a56dbb1c
PP
1102Set current value of extended library search path. If C<type> is
1103present and I<true>, works with END_LIBPATH, otherwise with
1104C<BEGIN_LIBPATH>.
615d1a09 1105
a56dbb1c 1106=back
615d1a09 1107
a56dbb1c
PP
1108(Note that some of these may be moved to different libraries -
1109eventually).
615d1a09 1110
615d1a09 1111
a56dbb1c 1112=head2 Misfeatures
615d1a09 1113
a56dbb1c 1114=over 4
615d1a09 1115
a56dbb1c 1116=item
615d1a09 1117
367f3c24
IZ
1118Since L<flock(3)> is present in EMX, but is not functional, it is
1119emulated by perl. To disable the emulations, set environment variable
1120C<USE_PERL_FLOCK=0>.
1121
1122=item
1123
1124Here is the list of things which may be "broken" on
55497cff
PP
1125EMX (from EMX docs):
1126
d7678ab8
CS
1127=over
1128
1129=item *
1130
1131The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not
1132implemented.
1133
1134=item *
1135
1136L<sock_init(3)> is not required and not implemented.
1137
1138=item *
1139
367f3c24 1140L<flock(3)> is not yet implemented (dummy function). (Perl has a workaround.)
d7678ab8
CS
1141
1142=item *
1143
1144L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1145
1146=item *
1147
1148L<waitpid(3)>:
1149
55497cff
PP
1150 WUNTRACED
1151 Not implemented.
1152 waitpid() is not implemented for negative values of PID.
1153
d7678ab8
CS
1154=back
1155
55497cff 1156Note that C<kill -9> does not work with the current version of EMX.
615d1a09 1157
a56dbb1c 1158=item
615d1a09 1159
72ea3524 1160Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
a56dbb1c 1161of F<sh.exe> plague perl as well.
615d1a09 1162
a56dbb1c 1163In particular, uppercase letters do not work in C<[...]>-patterns with
aa689395 1164the current pdksh.
615d1a09 1165
a56dbb1c 1166=back
615d1a09 1167
55497cff
PP
1168=head2 Modifications
1169
1170Perl modifies some standard C library calls in the following ways:
1171
1172=over 9
1173
1174=item C<popen>
1175
72ea3524 1176C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
55497cff
PP
1177
1178=item C<tmpnam>
1179
1180is created using C<TMP> or C<TEMP> environment variable, via
1181C<tempnam>.
1182
1183=item C<tmpfile>
1184
72ea3524 1185If the current directory is not writable, file is created using modified
55497cff
PP
1186C<tmpnam>, so there may be a race condition.
1187
1188=item C<ctermid>
1189
1190a dummy implementation.
1191
1192=item C<stat>
1193
1194C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1195
367f3c24
IZ
1196=item C<flock>
1197
1198Since L<flock(3)> is present in EMX, but is not functional, it is
1199emulated by perl. To disable the emulations, set environment variable
1200C<USE_PERL_FLOCK=0>.
1201
55497cff
PP
1202=back
1203
a56dbb1c 1204=head1 Perl flavors
615d1a09 1205
72ea3524 1206Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
aa689395 1207same basket (though EMX environment tries hard to overcome this
a56dbb1c
PP
1208limitations, so the situation may somehow improve). There are 4
1209executables for Perl provided by the distribution:
615d1a09 1210
a56dbb1c 1211=head2 F<perl.exe>
615d1a09 1212
a56dbb1c
PP
1213The main workhorse. This is a chimera executable: it is compiled as an
1214C<a.out>-style executable, but is linked with C<omf>-style dynamic
aa689395
PP
1215library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1216VIO application.
a56dbb1c
PP
1217
1218It can load perl dynamic extensions, and it can fork(). Unfortunately,
aa689395
PP
1219with the current version of EMX it cannot fork() with dynamic
1220extensions loaded (may be fixed by patches to EMX).
a56dbb1c
PP
1221
1222B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1223
1224=head2 F<perl_.exe>
1225
1226This is a statically linked C<a.out>-style executable. It can fork(),
1227but cannot load dynamic Perl extensions. The supplied executable has a
1228lot of extensions prebuilt, thus there are situations when it can
1229perform tasks not possible using F<perl.exe>, like fork()ing when
aa689395 1230having some standard extension loaded. This executable is a VIO
a56dbb1c
PP
1231application.
1232
1233B<Note.> A better behaviour could be obtained from C<perl.exe> if it
1234were statically linked with standard I<Perl extensions>, but
aa689395 1235dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
a56dbb1c
PP
1236be able to fork() with standard extensions, I<and> would be able to
1237dynamically load arbitrary extensions. Some changes to Makefiles and
1238hint files should be necessary to achieve this.
1239
1240I<This is also the only executable with does not require OS/2.> The
1241friends locked into C<M$> world would appreciate the fact that this
72ea3524 1242executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
a56dbb1c
PP
1243appropriate extender. See L<"Other OSes">.
1244
1245=head2 F<perl__.exe>
1246
aa689395 1247This is the same executable as F<perl___.exe>, but it is a PM
a56dbb1c
PP
1248application.
1249
aa689395 1250B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
a56dbb1c
PP
1251application are redirected to C<nul>. However, it is possible to see
1252them if you start C<perl__.exe> from a PM program which emulates a
aa689395 1253console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
a56dbb1c
PP
1254possible> to use Perl debugger (see L<perldebug>) to debug your PM
1255application.
1256
aa689395 1257This flavor is required if you load extensions which use PM, like
a56dbb1c
PP
1258the forthcoming C<Perl/Tk>.
1259
1260=head2 F<perl___.exe>
1261
1262This is an C<omf>-style executable which is dynamically linked to
aa689395 1263F<perl.dll> and CRT DLL. I know no advantages of this executable
a56dbb1c
PP
1264over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1265that the build process is not so convoluted as with C<perl.exe>.
1266
aa689395 1267It is a VIO application.
a56dbb1c
PP
1268
1269=head2 Why strange names?
1270
1271Since Perl processes the C<#!>-line (cf.
1272L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1273L<perldiag/"Not a perl script">,
1274L<perldiag/"No Perl script found in input">), it should know when a
1275program I<is a Perl>. There is some naming convention which allows
1276Perl to distinguish correct lines from wrong ones. The above names are
72ea3524 1277almost the only names allowed by this convention which do not contain
a56dbb1c
PP
1278digits (which have absolutely different semantics).
1279
1280=head2 Why dynamic linking?
1281
1282Well, having several executables dynamically linked to the same huge
1283library has its advantages, but this would not substantiate the
1284additional work to make it compile. The reason is stupid-but-quick
1285"hard" dynamic linking used by OS/2.
1286
72ea3524
IZ
1287The address tables of DLLs are patched only once, when they are
1288loaded. The addresses of entry points into DLLs are guaranteed to be
a56dbb1c
PP
1289the same for all programs which use the same DLL, which reduces the
1290amount of runtime patching - once DLL is loaded, its code is
1291read-only.
1292
1293While this allows some performance advantages, this makes life
72ea3524 1294terrible for developers, since the above scheme makes it impossible
a56dbb1c
PP
1295for a DLL to be resolved to a symbol in the .EXE file, since this
1296would need a DLL to have different relocations tables for the
1297executables which use it.
1298
1299However, a Perl extension is forced to use some symbols from the perl
1300executable, say to know how to find the arguments provided on the perl
1301internal evaluation stack. The solution is that the main code of
1302interpreter should be contained in a DLL, and the F<.EXE> file just loads
1303this DLL into memory and supplies command-arguments.
1304
72ea3524 1305This I<greatly> increases the load time for the application (as well as
a56dbb1c 1306the number of problems during compilation). Since interpreter is in a DLL,
aa689395
PP
1307the CRT is basically forced to reside in a DLL as well (otherwise
1308extensions would not be able to use CRT).
a56dbb1c
PP
1309
1310=head2 Why chimera build?
1311
aa689395 1312Current EMX environment does not allow DLLs compiled using Unixish
a56dbb1c
PP
1313C<a.out> format to export symbols for data. This forces C<omf>-style
1314compile of F<perl.dll>.
1315
aa689395 1316Current EMX environment does not allow F<.EXE> files compiled in
a56dbb1c
PP
1317C<omf> format to fork(). fork() is needed for exactly three Perl
1318operations:
1319
1320=over 4
1321
1322=item explicit fork()
1323
1324in the script, and
1325
1326=item open FH, "|-"
1327
1328=item open FH, "-|"
1329
1330opening pipes to itself.
1331
1332=back
1333
1334While these operations are not questions of life and death, a lot of
1335useful scripts use them. This forces C<a.out>-style compile of
1336F<perl.exe>.
1337
1338
1339=head1 ENVIRONMENT
1340
aa689395
PP
1341Here we list environment variables with are either OS/2- and DOS- and
1342Win*-specific, or are more important under OS/2 than under other OSes.
a56dbb1c
PP
1343
1344=head2 C<PERLLIB_PREFIX>
1345
aa689395 1346Specific for EMX port. Should have the form
a56dbb1c
PP
1347
1348 path1;path2
1349
1350or
1351
1352 path1 path2
1353
1354If the beginning of some prebuilt path matches F<path1>, it is
1355substituted with F<path2>.
1356
1357Should be used if the perl library is moved from the default
1358location in preference to C<PERL(5)LIB>, since this would not leave wrong
eb447b86
IZ
1359entries in @INC. Say, if the compiled version of perl looks for @INC
1360in F<f:/perllib/lib>, and you want to install the library in
1361F<h:/opt/gnu>, do
1362
1363 set PERLLIB_PREFIX=f:/perllib/lib;h:/opt/gnu
a56dbb1c
PP
1364
1365=head2 C<PERL_BADLANG>
1366
1367If 1, perl ignores setlocale() failing. May be useful with some
1368strange I<locale>s.
1369
1370=head2 C<PERL_BADFREE>
1371
1372If 1, perl would not warn of in case of unwarranted free(). May be
1373useful in conjunction with the module DB_File, since Berkeley DB
1374memory handling code is buggy.
1375
1376=head2 C<PERL_SH_DIR>
1377
aa689395 1378Specific for EMX port. Gives the directory part of the location for
a56dbb1c
PP
1379F<sh.exe>.
1380
367f3c24
IZ
1381=head2 C<USE_PERL_FLOCK>
1382
1383Specific for EMX port. Since L<flock(3)> is present in EMX, but is not
1384functional, it is emulated by perl. To disable the emulations, set
1385environment variable C<USE_PERL_FLOCK=0>.
1386
a56dbb1c
PP
1387=head2 C<TMP> or C<TEMP>
1388
aa689395 1389Specific for EMX port. Used as storage place for temporary files, most
a56dbb1c
PP
1390notably C<-e> scripts.
1391
1392=head1 Evolution
1393
1394Here we list major changes which could make you by surprise.
1395
1396=head2 Priorities
1397
1398C<setpriority> and C<getpriority> are not compatible with earlier
1399ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1400
72ea3524 1401=head2 DLL name mangling
a56dbb1c
PP
1402
1403With the release 5.003_01 the dynamically loadable libraries
1404should be rebuilt. In particular, DLLs are now created with the names
1405which contain a checksum, thus allowing workaround for OS/2 scheme of
1406caching DLLs.
1407
1408=head2 Threading
1409
aa689395 1410As of release 5.003_01 perl is linked to multithreaded CRT
a56dbb1c
PP
1411DLL. Perl itself is not multithread-safe, as is not perl
1412malloc(). However, extensions may use multiple thread on their own
1413risk.
1414
aa689395 1415Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
a56dbb1c
PP
1416
1417=head2 Calls to external programs
1418
1419Due to a popular demand the perl external program calling has been
72ea3524 1420changed wrt Andreas Kaiser's port. I<If> perl needs to call an
a56dbb1c
PP
1421external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1422whatever is the override, see L<"PERL_SH_DIR">.
1423
1424Thus means that you need to get some copy of a F<sh.exe> as well (I
1425use one from pdksh). The drive F: above is set up automatically during
1426the build to a correct value on the builder machine, but is
1427overridable at runtime,
1428
1429B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1430one non-overridable shell per platform. The obvious choices for OS/2
1431are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
1432with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
aa689395
PP
1433100% compatibility with the scripts coming from *nix. As an added benefit
1434this works as well under DOS if you use DOS-enabled port of pdksh
1435(see L<"Prerequisites">).
a56dbb1c 1436
aa689395 1437B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
a56dbb1c
PP
1438via fork()/exec(), and there is I<no> functioning exec() on
1439OS/2. exec() is emulated by EMX by asyncroneous call while the caller
72ea3524 1440waits for child completion (to pretend that the C<pid> did not change). This
a56dbb1c
PP
1441means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1442which may lead to some resources taken from the system (even if we do
1443not count extra work needed for fork()ing).
1444
72ea3524
IZ
1445Note that this a lesser issue now when we do not spawn F<sh.exe>
1446unless needed (metachars found).
1447
1448One can always start F<cmd.exe> explicitly via
a56dbb1c
PP
1449
1450 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1451
72ea3524 1452If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
a56dbb1c
PP
1453scripts, the long-term solution proposed on p5-p is to have a directive
1454
1455 use OS2::Cmd;
1456
1457which will override system(), exec(), C<``>, and
1458C<open(,'...|')>. With current perl you may override only system(),
1459readpipe() - the explicit version of C<``>, and maybe exec(). The code
1460will substitute the one-argument call to system() by
1461C<CORE::system('cmd.exe', '/c', shift)>.
1462
1463If you have some working code for C<OS2::Cmd>, please send it to me,
1464I will include it into distribution. I have no need for such a module, so
1465cannot test it.
1466
df3ef7a9
IZ
1467=head2 Memory allocation
1468
1469Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
1470for speed, but perl is not, since its malloc is lightning-fast.
1471Unfortunately, it is also quite frivolous with memory usage as well.
1472
1473Since kitchen-top machines are usually low on memory, perl is compiled with
1474all the possible memory-saving options. This probably makes perl's
1475malloc() as greedy with memory as the neighbor's malloc(), but still
1476much quickier. Note that this is true only for a "typical" usage,
1477it is possible that the perl malloc will be worse for some very special usage.
1478
1479Combination of perl's malloc() and rigid DLL name resolution creates
1480a special problem with library functions which expect their return value to
1481be free()d by system's free(). To facilitate extensions which need to call
1482such functions, system memory-allocation functions are still available with
1483the prefix C<emx_> added. (Currently only DLL perl has this, it should
1484propagate to F<perl_.exe> shortly.)
1485
a56dbb1c
PP
1486=cut
1487
1488OS/2 extensions
1489~~~~~~~~~~~~~~~
72ea3524 1490I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
a56dbb1c
PP
1491into my ftp directory, mirrored on CPAN. I made
1492some minor changes needed to compile them by standard tools. I cannot
1493test UPM and FTP, so I will appreciate your feedback. Other extensions
1494there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1495files - and maybe some other extensions at the time you read it.
1496
1497Note that OS2 perl defines 2 pseudo-extension functions
aa689395
PP
1498OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1499L<Prebuilt methods>).
a56dbb1c
PP
1500
1501The -R switch of older perl is deprecated. If you need to call a REXX code
1502which needs access to variables, include the call into a REXX compartment
1503created by
1504 REXX_call {...block...};
1505
1506Two new functions are supported by REXX code,
1507 REXX_eval 'string';
1508 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1509
1510If you have some other extensions you want to share, send the code to
1511me. At least two are available: tied access to EA's, and tied access
1512to system databases.
615d1a09 1513
a56dbb1c 1514=head1 AUTHOR
615d1a09 1515
a56dbb1c 1516Ilya Zakharevich, ilya@math.ohio-state.edu
615d1a09 1517
a56dbb1c 1518=head1 SEE ALSO
615d1a09 1519
a56dbb1c 1520perl(1).
615d1a09 1521
a56dbb1c 1522=cut
615d1a09 1523