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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.
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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
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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
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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
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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
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40=cut
41
42Contents
43
df3ef7a9 44 perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.
a56dbb1c 45
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46 NAME
47 SYNOPSIS
48 DESCRIPTION
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49 - Target
50 - Other OSes
51 - Prerequisites
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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
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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
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60 - Automatic binary installation
61 - Manual binary installation
62 - Warning
df3ef7a9 63 Accessing documentation
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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
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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
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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
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88 - setpriority, getpriority
89 - system()
aa689395 90 - extproc on the first line
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91 - Additional modules:
92 - Prebuilt methods:
93 - Misfeatures
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94 - Modifications
95 Perl flavors
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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
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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
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112 - Threading
113 - Calls to external programs
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114 - Memory allocation
115 AUTHOR
116 SEE ALSO
117
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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
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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).
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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
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145convenience methods of Object-REXX. (Is it possible at all? I know
146of no Object-REXX API.)
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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
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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,
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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.
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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
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177fact RSX is required if there is no VCPI present. Note the
178RSX requires DPMI.
a56dbb1c 179
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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
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185 ftp://ftp.cdrom.com/pub/os2/emx09c/
186 ftp://hobbes.nmsu.edu/os2/unix/emx09c/
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187
188The runtime component should have the name F<emxrt.zip>.
189
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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
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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
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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
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214
215Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
216
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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
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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
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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
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243
244=back
245
aa689395 246=head2 Starting Perl programs under OS/2 (and DOS and...)
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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
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259the following at the start of your perl script:
260
aa689395 261 extproc perl -S -my_opts
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262
263rename your program to F<foo.cmd>, and start it by typing
264
265 foo arg1 arg2 arg3
266
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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
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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>).
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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>:
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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
aa689395 293=head2 Starting OS/2 (and DOS) programs under Perl
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294
295This is what system() (see L<perlfunc/system>), C<``> (see
296L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
297are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
298do).
299
300Note however that to use some of these operators you need to have a
aa689395 301sh-syntax shell installed (see L<"Pdksh">,
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302L<"Frequently asked questions">), and perl should be able to find it
303(see L<"PERL_SH_DIR">).
304
305The only cases when the shell is not used is the multi-argument
306system() (see L<perlfunc/system>)/exec() (see L<perlfunc/exec>), and
307one-argument version thereof without redirection and shell
308meta-characters.
309
310=head1 Frequently asked questions
311
72ea3524 312=head2 I cannot run external programs
a56dbb1c 313
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314=over 4
315
316=item
317
a56dbb1c 318Did you run your programs with C<-w> switch? See
aa689395 319L<Starting OS/2 (and DOS) programs under Perl>.
a56dbb1c 320
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321=item
322
323Do you try to run I<internal> shell commands, like C<`copy a b`>
324(internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
72ea3524 325need to specify your shell explicitly, like C<`cmd /c copy a b`>,
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326since Perl cannot deduce which commands are internal to your shell.
327
328=back
329
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330=head2 I cannot embed perl into my program, or use F<perl.dll> from my
331program.
332
333=over 4
334
aa689395 335=item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
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336
337If not, you need to build a stand-alone DLL for perl. Contact me, I
338did it once. Sockets would not work, as a lot of other stuff.
339
aa689395 340=item Did you use L<ExtUtils::Embed>?
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341
342I had reports it does not work. Somebody would need to fix it.
343
344=back
345
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346=head2 C<``> and pipe-C<open> do not work under DOS.
347
72ea3524 348This may a variant of just L<"I cannot run external programs">, or a
aa689395 349deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
72ea3524 350for these commands to work, and you may need a port of F<sh.exe> which
55497cff 351understands command arguments. One of such ports is listed in
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352L<"Prerequisites"> under RSX. Do not forget to set variable
353C<L<"PERL_SH_DIR">> as well.
354
355DPMI is required for RSX.
356
357=head2 Cannot start C<find.exe "pattern" file>
55497cff 358
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359Use one of
360
361 system 'cmd', '/c', 'find "pattern" file';
362 `cmd /c 'find "pattern" file'`
363
364This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
365C<perl.exe>, but this is a price to pay if you want to use
366non-conforming program. In fact F<find.exe> cannot be started at all
367using C library API only. Otherwise the following command-lines were
368equivalent:
369
370 find "pattern" file
371 find pattern file
55497cff 372
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373=head1 INSTALLATION
374
375=head2 Automatic binary installation
376
72ea3524 377The most convenient way of installing perl is via perl installer
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378F<install.exe>. Just follow the instructions, and 99% of the
379installation blues would go away.
380
381Note however, that you need to have F<unzip.exe> on your path, and
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382EMX environment I<running>. The latter means that if you just
383installed EMX, and made all the needed changes to F<Config.sys>,
384you may need to reboot in between. Check EMX runtime by running
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385
386 emxrev
387
388A folder is created on your desktop which contains some useful
389objects.
390
391B<Things not taken care of by automatic binary installation:>
392
393=over 15
394
395=item C<PERL_BADLANG>
396
397may be needed if you change your codepage I<after> perl installation,
aa689395 398and the new value is not supported by EMX. See L<"PERL_BADLANG">.
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399
400=item C<PERL_BADFREE>
401
402see L<"PERL_BADFREE">.
403
404=item F<Config.pm>
405
406This file resides somewhere deep in the location you installed your
407perl library, find it out by
408
409 perl -MConfig -le "print $INC{'Config.pm'}"
410
411While most important values in this file I<are> updated by the binary
412installer, some of them may need to be hand-edited. I know no such
413data, please keep me informed if you find one.
414
415=back
416
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417B<NOTE>. Because of a typo the binary installer of 5.00305
418would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
419remove this variable and put C<L<PERL_SH_DIR>> instead.
420
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421=head2 Manual binary installation
422
72ea3524 423As of version 5.00305, OS/2 perl binary distribution comes split
a56dbb1c 424into 11 components. Unfortunately, to enable configurable binary
aa689395 425installation, the file paths in the zip files are not absolute, but
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426relative to some directory.
427
428Note that the extraction with the stored paths is still necessary
aa689395 429(default with unzip, specify C<-d> to pkunzip). However, you
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430need to know where to extract the files. You need also to manually
431change entries in F<Config.sys> to reflect where did you put the
72ea3524 432files. Note that if you have some primitive unzipper (like
aa689395 433pkunzip), you may get a lot of warnings/errors during
72ea3524 434unzipping. Upgrade to C<(w)unzip>.
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435
436Below is the sample of what to do to reproduce the configuration on my
437machine:
438
439=over 3
440
441=item Perl VIO and PM executables (dynamically linked)
442
443 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
444 unzip perl_exc.zip *.dll -d f:/emx.add/dll
445
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446(have the directories with C<*.exe> on PATH, and C<*.dll> on
447LIBPATH);
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448
449=item Perl_ VIO executable (statically linked)
450
451 unzip perl_aou.zip -d f:/emx.add/bin
452
aa689395 453(have the directory on PATH);
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454
455=item Executables for Perl utilities
456
457 unzip perl_utl.zip -d f:/emx.add/bin
458
aa689395 459(have the directory on PATH);
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460
461=item Main Perl library
462
463 unzip perl_mlb.zip -d f:/perllib/lib
464
465If this directory is preserved, you do not need to change
466anything. However, for perl to find it if it is changed, you need to
467C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
468
469=item Additional Perl modules
470
471 unzip perl_ste.zip -d f:/perllib/lib/site_perl
472
473If you do not change this directory, do nothing. Otherwise put this
474directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
475variable. Do not use C<PERL5LIB> unless you have it set already. See
476L<perl/"ENVIRONMENT">.
477
478=item Tools to compile Perl modules
479
480 unzip perl_blb.zip -d f:/perllib/lib
481
482If this directory is preserved, you do not need to change
483anything. However, for perl to find it if it is changed, you need to
484C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
485
486=item Manpages for Perl and utilities
487
488 unzip perl_man.zip -d f:/perllib/man
489
490This directory should better be on C<MANPATH>. You need to have a
aa689395 491working man to access these files.
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492
493=item Manpages for Perl modules
494
495 unzip perl_mam.zip -d f:/perllib/man
496
497This directory should better be on C<MANPATH>. You need to have a
aa689395 498working man to access these files.
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499
500=item Source for Perl documentation
501
502 unzip perl_pod.zip -d f:/perllib/lib
503
504This is used by by C<perldoc> program (see L<perldoc>), and may be used to
aa689395 505generate HTML documentation usable by WWW browsers, and
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506documentation in zillions of other formats: C<info>, C<LaTeX>,
507C<Acrobat>, C<FrameMaker> and so on.
508
aa689395 509=item Perl manual in F<.INF> format
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510
511 unzip perl_inf.zip -d d:/os2/book
512
513This directory should better be on C<BOOKSHELF>.
514
515=item Pdksh
516
517 unzip perl_sh.zip -d f:/bin
518
72ea3524 519This is used by perl to run external commands which explicitly
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520require shell, like the commands using I<redirection> and I<shell
521metacharacters>. It is also used instead of explicit F</bin/sh>.
522
523Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
524the above location.
525
aa689395 526B<Note.> It may be possible to use some other sh-compatible shell
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527(I<not tested>).
528
529=back
530
531After you installed the components you needed and updated the
532F<Config.sys> correspondingly, you need to hand-edit
533F<Config.pm>. This file resides somewhere deep in the location you
534installed your perl library, find it out by
535
536 perl -MConfig -le "print $INC{'Config.pm'}"
537
538You need to correct all the entries which look like file paths (they
539currently start with C<f:/>).
540
541=head2 B<Warning>
542
543The automatic and manual perl installation leave precompiled paths
544inside perl executables. While these paths are overwriteable (see
545L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
546binary editing of paths inside the executables/DLLs.
547
548=head1 Accessing documentation
549
550Depending on how you built/installed perl you may have (otherwise
551identical) Perl documentation in the following formats:
552
553=head2 OS/2 F<.INF> file
554
aa689395 555Most probably the most convenient form. Under OS/2 view it as
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556
557 view perl
558 view perl perlfunc
559 view perl less
560 view perl ExtUtils::MakeMaker
561
562(currently the last two may hit a wrong location, but this may improve
aa689395 563soon). Under Win* see L<"SYNOPSIS">.
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564
565If you want to build the docs yourself, and have I<OS/2 toolkit>, run
566
567 pod2ipf > perl.ipf
568
569in F</perllib/lib/pod> directory, then
570
571 ipfc /inf perl.ipf
572
573(Expect a lot of errors during the both steps.) Now move it on your
574BOOKSHELF path.
575
576=head2 Plain text
577
578If you have perl documentation in the source form, perl utilities
aa689395 579installed, and GNU groff installed, you may use
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580
581 perldoc perlfunc
582 perldoc less
583 perldoc ExtUtils::MakeMaker
584
72ea3524 585to access the perl documentation in the text form (note that you may get
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586better results using perl manpages).
587
588Alternately, try running pod2text on F<.pod> files.
589
590=head2 Manpages
591
aa689395 592If you have man installed on your system, and you installed perl
a56dbb1c 593manpages, use something like this:
5243f9ae 594
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595 man perlfunc
596 man 3 less
597 man ExtUtils.MakeMaker
5243f9ae 598
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599to access documentation for different components of Perl. Start with
600
601 man perl
602
603Note that dot (F<.>) is used as a package separator for documentation
604for packages, and as usual, sometimes you need to give the section - C<3>
605above - to avoid shadowing by the I<less(1) manpage>.
606
607Make sure that the directory B<above> the directory with manpages is
608on our C<MANPATH>, like this
609
610 set MANPATH=c:/man;f:/perllib/man
611
aa689395 612=head2 HTML
a56dbb1c
PP
613
614If you have some WWW browser available, installed the Perl
615documentation in the source form, and Perl utilities, you can build
aa689395 616HTML docs. Cd to directory with F<.pod> files, and do like this
a56dbb1c
PP
617
618 cd f:/perllib/lib/pod
5243f9ae 619 pod2html
5243f9ae 620
a56dbb1c
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621After this you can direct your browser the file F<perl.html> in this
622directory, and go ahead with reading docs, like this:
5243f9ae 623
a56dbb1c 624 explore file:///f:/perllib/lib/pod/perl.html
5243f9ae 625
aa689395 626Alternatively you may be able to get these docs prebuilt from CPAN.
5243f9ae 627
aa689395 628=head2 GNU C<info> files
bb14ff96 629
aa689395 630Users of Emacs would appreciate it very much, especially with
a56dbb1c
PP
631C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
632or, alternately, prebuilt info pages.
615d1a09 633
a56dbb1c
PP
634=head2 F<.PDF> files
635
636for C<Acrobat> are available on CPAN (for slightly old version of
637perl).
638
639=head2 C<LaTeX> docs
640
641can be constructed using C<pod2latex>.
642
643=head1 BUILD
644
645Here we discuss how to build Perl under OS/2. There is an alternative
646(but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
647
648=head2 Prerequisites
649
aa689395
PP
650You need to have the latest EMX development environment, the full
651GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
a56dbb1c
PP
652earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
653check use
654
655 find --version
656 sort --version
657
658). You need the latest version of F<pdksh> installed as F<sh.exe>.
659
660Possible locations to get this from are
661
d7678ab8 662 ftp://hobbes.nmsu.edu/os2/unix/
a56dbb1c
PP
663 ftp://ftp.cdrom.com/pub/os2/unix/
664 ftp://ftp.cdrom.com/pub/os2/dev32/
d7678ab8 665 ftp://ftp.cdrom.com/pub/os2/emx09c/
a56dbb1c
PP
666
667
668Make sure that no copies or perl are currently running. Later steps
669of the build may fail since an older version of perl.dll loaded into
670memory may be found.
671
672Also make sure that you have F</tmp> directory on the current drive,
673and F<.> directory in your C<LIBPATH>. One may try to correct the
674latter condition by
675
676 set BEGINLIBPATH .
677
678if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
679
aa689395 680Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
a56dbb1c
PP
681script in F</emx/lib> directory.
682
aa689395 683Check that you have link386 installed. It comes standard with OS/2,
a56dbb1c
PP
684but may be not installed due to customization. If typing
685
686 link386
687
688shows you do not have it, do I<Selective install>, and choose C<Link
72ea3524 689object modules> in I<Optional system utilities/More>. If you get into
aa689395 690link386, press C<Ctrl-C>.
a56dbb1c
PP
691
692=head2 Getting perl source
693
72ea3524 694You need to fetch the latest perl source (including developers
a56dbb1c
PP
695releases). With some probability it is located in
696
697 http://www.perl.com/CPAN/src/5.0
698 http://www.perl.com/CPAN/src/5.0/unsupported
699
700If not, you may need to dig in the indices to find it in the directory
701of the current maintainer.
702
72ea3524 703Quick cycle of developers release may break the OS/2 build time to
a56dbb1c
PP
704time, looking into
705
706 http://www.perl.com/CPAN/ports/os2/ilyaz/
707
708may indicate the latest release which was publicly released by the
709maintainer. Note that the release may include some additional patches
710to apply to the current source of perl.
711
712Extract it like this
713
714 tar vzxf perl5.00409.tar.gz
715
716You may see a message about errors while extracting F<Configure>. This is
717because there is a conflict with a similarly-named file F<configure>.
718
a56dbb1c
PP
719Change to the directory of extraction.
720
721=head2 Application of the patches
722
723You need to apply the patches in F<./os2/diff.*> and
724F<./os2/POSIX.mkfifo> like this:
725
726 gnupatch -p0 < os2\POSIX.mkfifo
df3ef7a9 727 gnupatch -p0 < os2\diff.configure
a56dbb1c
PP
728
729You may also need to apply the patches supplied with the binary
730distribution of perl.
731
aa689395 732Note also that the F<db.lib> and F<db.a> from the EMX distribution
a56dbb1c 733are not suitable for multi-threaded compile (note that currently perl
aa689395
PP
734is not multithread-safe, but is compiled as multithreaded for
735compatibility with XFree86-OS/2). Get a corrected one from
a56dbb1c
PP
736
737 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
738
739=head2 Hand-editing
740
741You may look into the file F<./hints/os2.sh> and correct anything
742wrong you find there. I do not expect it is needed anywhere.
615d1a09 743
a56dbb1c 744=head2 Making
615d1a09 745
a56dbb1c 746 sh Configure -des -D prefix=f:/perllib
615d1a09 747
aa689395 748C<prefix> means: where to install the resulting perl library. Giving
a56dbb1c
PP
749correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
750see L<"PERLLIB_PREFIX">.
5243f9ae 751
a56dbb1c 752I<Ignore the message about missing C<ln>, and about C<-c> option to
aa689395 753tr>. In fact if you can trace where the latter spurious warning
a56dbb1c 754comes from, please inform me.
615d1a09 755
a56dbb1c 756Now
5243f9ae 757
a56dbb1c 758 make
5243f9ae 759
a56dbb1c
PP
760At some moment the built may die, reporting a I<version mismatch> or
761I<unable to run F<perl>>. This means that most of the build has been
762finished, and it is the time to move the constructed F<perl.dll> to
aa689395
PP
763some I<absolute> location in LIBPATH. After this is done the build
764should finish without a lot of fuss. I<One can avoid the interruption
765if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
766probably this is not needed anymore, since F<miniperl.exe> is linked
767statically now.>
615d1a09 768
a56dbb1c
PP
769Warnings which are safe to ignore: I<mkfifo() redefined> inside
770F<POSIX.c>.
615d1a09 771
a56dbb1c
PP
772=head2 Testing
773
774Now run
775
776 make test
777
72ea3524 778Some tests (4..6) should fail. Some perl invocations should end in a
a56dbb1c
PP
779segfault (system error C<SYS3175>). To get finer error reports,
780
781 cd t
aa689395 782 perl harness
a56dbb1c
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783
784The report you get may look like
785
786 Failed Test Status Wstat Total Fail Failed List of failed
787 ---------------------------------------------------------------
788 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
789 lib/io_pipe.t 3 768 6 ?? % ??
790 lib/io_sock.t 3 768 5 ?? % ??
791 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
72ea3524 792 Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
a56dbb1c
PP
793
794Note that using `make test' target two more tests may fail: C<op/exec:1>
aa689395 795because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
55497cff
PP
796that the buffers are not flushed on C<_exit> (this is a bug in the test
797which assumes that tty output is buffered).
a56dbb1c 798
aa689395 799I submitted a patch to EMX which makes it possible to fork() with EMX
72ea3524
IZ
800dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
801that soon the number of failing tests may decrease yet more.
802
df3ef7a9
IZ
803However, the test F<lib/io_udp.t> is disabled, since it never terminates, I
804do not know why. Comments/fixes welcome.
72ea3524 805
a56dbb1c
PP
806The reasons for failed tests are:
807
808=over 8
809
810=item F<io/fs.t>
811
812Checks I<file system> operations. Tests:
813
814=over 10
815
816=item 2-5, 7-11
817
818Check C<link()> and C<inode count> - nonesuch under OS/2.
819
820=item 18
821
822Checks C<atime> and C<mtime> of C<stat()> - I could not understand this test.
823
824=item 25
825
826Checks C<truncate()> on a filehandle just opened for write - I do not
827know why this should or should not work.
828
829=back
830
831=item F<lib/io_pipe.t>
832
aa689395 833Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
a56dbb1c
PP
834dynamic extension loaded - unsupported now.
835
836=item F<lib/io_sock.t>
837
aa689395 838Checks C<IO::Socket> module. Some feature of EMX - test fork()s
a56dbb1c
PP
839with dynamic extension loaded - unsupported now.
840
841=item F<op/stat.t>
842
843Checks C<stat()>. Tests:
844
845=over 4
846
847=item 3
848
849Checks C<inode count> - nonesuch under OS/2.
850
851=item 4
852
853Checks C<mtime> and C<ctime> of C<stat()> - I could not understand this test.
854
855=item 20
856
857Checks C<-x> - determined by the file extension only under OS/2.
858
859=item 35
860
861Needs F</usr/bin>.
862
863=item 39
864
865Checks C<-t> of F</dev/null>. Should not fail!
866
867=back
868
869=back
870
871In addition to errors, you should get a lot of warnings.
872
873=over 4
874
875=item A lot of `bad free'
876
877in databases related to Berkeley DB. This is a confirmed bug of
878DB. You may disable this warnings, see L<"PERL_BADFREE">.
879
880=item Process terminated by SIGTERM/SIGINT
881
882This is a standard message issued by OS/2 applications. *nix
883applications die in silence. It is considered a feature. One can
884easily disable this by appropriate sighandlers.
885
886However the test engine bleeds these message to screen in unexpected
887moments. Two messages of this kind I<should> be present during
888testing.
889
890=item F<*/sh.exe>: ln: not found
891
892=item C<ls>: /dev: No such file or directory
893
894The last two should be self-explanatory. The test suite discovers that
895the system it runs on is not I<that much> *nixish.
896
897=back
615d1a09
PP
898
899A lot of `bad free'... in databases, bug in DB confirmed on other
5243f9ae 900platforms. You may disable it by setting PERL_BADFREE environment variable
a56dbb1c 901to 1.
615d1a09 902
a56dbb1c 903=head2 Installing the built perl
615d1a09 904
a56dbb1c 905Run
615d1a09 906
a56dbb1c 907 make install
615d1a09 908
a56dbb1c
PP
909It would put the generated files into needed locations. Manually put
910F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
aa689395 911PATH, F<perl.dll> to a location on your LIBPATH.
615d1a09 912
a56dbb1c 913Run
615d1a09 914
a56dbb1c 915 make cmdscripts INSTALLCMDDIR=d:/ir/on/path
615d1a09 916
a56dbb1c 917to convert perl utilities to F<.cmd> files and put them on
aa689395 918PATH. You need to put F<.EXE>-utilities on path manually. They are
a56dbb1c
PP
919installed in C<$prefix/bin>, here C<$prefix> is what you gave to
920F<Configure>, see L<Making>.
921
922=head2 C<a.out>-style build
923
924Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
925
926 make perl_
927
928test and install by
929
930 make aout_test
931 make aout_install
932
aa689395 933Manually put F<perl_.exe> to a location on your PATH.
a56dbb1c
PP
934
935Since C<perl_> has the extensions prebuilt, it does not suffer from
72ea3524 936the I<dynamic extensions + fork()> syndrome, thus the failing tests
a56dbb1c
PP
937look like
938
939 Failed Test Status Wstat Total Fail Failed List of failed
940 ---------------------------------------------------------------
941 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
942 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
943 Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
944
945B<Note.> The build process for C<perl_> I<does not know> about all the
946dependencies, so you should make sure that anything is up-to-date,
947say, by doing
948
949 make perl.dll
950
951first.
952
953=head1 Build FAQ
954
955=head2 Some C</> became C<\> in pdksh.
956
957You have a very old pdksh. See L<Prerequisites>.
958
959=head2 C<'errno'> - unresolved external
960
961You do not have MT-safe F<db.lib>. See L<Prerequisites>.
962
aa689395 963=head2 Problems with tr
a56dbb1c 964
aa689395 965reported with very old version of tr.
a56dbb1c
PP
966
967=head2 Some problem (forget which ;-)
968
aa689395 969You have an older version of F<perl.dll> on your LIBPATH, which
a56dbb1c
PP
970broke the build of extensions.
971
972=head2 Library ... not found
973
974You did not run C<omflibs>. See L<Prerequisites>.
975
976=head2 Segfault in make
977
aa689395 978You use an old version of GNU make. See L<Prerequisites>.
a56dbb1c
PP
979
980=head1 Specific (mis)features of OS/2 port
981
982=head2 C<setpriority>, C<getpriority>
983
984Note that these functions are compatible with *nix, not with the older
985ports of '94 - 95. The priorities are absolute, go from 32 to -95,
72ea3524 986lower is quicker. 0 is the default priority.
a56dbb1c
PP
987
988=head2 C<system()>
989
990Multi-argument form of C<system()> allows an additional numeric
991argument. The meaning of this argument is described in
992L<OS2::Process>.
993
aa689395
PP
994=head2 C<extproc> on the first line
995
996If the first chars of a script are C<"extproc ">, this line is treated
997as C<#!>-line, thus all the switches on this line are processed (twice
998if script was started via cmd.exe).
999
a56dbb1c 1000=head2 Additional modules:
615d1a09 1001
a56dbb1c
PP
1002L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. This
1003modules provide access to additional numeric argument for C<system>,
1004to DLLs having functions with REXX signature and to REXX runtime, to
1005OS/2 databases in the F<.INI> format, and to Extended Attributes.
615d1a09 1006
72ea3524 1007Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
a56dbb1c 1008C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
615d1a09 1009
a56dbb1c 1010=head2 Prebuilt methods:
615d1a09 1011
a56dbb1c 1012=over 4
615d1a09 1013
a56dbb1c 1014=item C<File::Copy::syscopy>
615d1a09 1015
d7678ab8 1016used by C<File::Copy::copy>, see L<File::Copy>.
615d1a09 1017
a56dbb1c 1018=item C<DynaLoader::mod2fname>
615d1a09 1019
72ea3524 1020used by C<DynaLoader> for DLL name mangling.
615d1a09 1021
a56dbb1c 1022=item C<Cwd::current_drive()>
615d1a09 1023
a56dbb1c 1024Self explanatory.
615d1a09 1025
a56dbb1c 1026=item C<Cwd::sys_chdir(name)>
615d1a09 1027
a56dbb1c 1028leaves drive as it is.
615d1a09 1029
a56dbb1c 1030=item C<Cwd::change_drive(name)>
615d1a09 1031
615d1a09 1032
a56dbb1c 1033=item C<Cwd::sys_is_absolute(name)>
615d1a09 1034
a56dbb1c 1035means has drive letter and is_rooted.
615d1a09 1036
a56dbb1c 1037=item C<Cwd::sys_is_rooted(name)>
615d1a09 1038
a56dbb1c 1039means has leading C<[/\\]> (maybe after a drive-letter:).
615d1a09 1040
a56dbb1c 1041=item C<Cwd::sys_is_relative(name)>
615d1a09 1042
a56dbb1c 1043means changes with current dir.
615d1a09 1044
a56dbb1c 1045=item C<Cwd::sys_cwd(name)>
615d1a09 1046
aa689395 1047Interface to cwd from EMX. Used by C<Cwd::cwd>.
615d1a09 1048
a56dbb1c 1049=item C<Cwd::sys_abspath(name, dir)>
615d1a09 1050
a56dbb1c
PP
1051Really really odious function to implement. Returns absolute name of
1052file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1053current dir.
615d1a09 1054
a56dbb1c 1055=item C<Cwd::extLibpath([type])
615d1a09 1056
a56dbb1c
PP
1057Get current value of extended library search path. If C<type> is
1058present and I<true>, works with END_LIBPATH, otherwise with
1059C<BEGIN_LIBPATH>.
615d1a09 1060
a56dbb1c 1061=item C<Cwd::extLibpath_set( path [, type ] )>
615d1a09 1062
a56dbb1c
PP
1063Set current value of extended library search path. If C<type> is
1064present and I<true>, works with END_LIBPATH, otherwise with
1065C<BEGIN_LIBPATH>.
615d1a09 1066
a56dbb1c 1067=back
615d1a09 1068
a56dbb1c
PP
1069(Note that some of these may be moved to different libraries -
1070eventually).
615d1a09 1071
615d1a09 1072
a56dbb1c 1073=head2 Misfeatures
615d1a09 1074
a56dbb1c 1075=over 4
615d1a09 1076
a56dbb1c 1077=item
615d1a09 1078
d7678ab8 1079Since L<flock(3)> is present in EMX, but is not functional, the same is
55497cff
PP
1080true for perl. Here is the list of things which may be "broken" on
1081EMX (from EMX docs):
1082
d7678ab8
CS
1083=over
1084
1085=item *
1086
1087The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not
1088implemented.
1089
1090=item *
1091
1092L<sock_init(3)> is not required and not implemented.
1093
1094=item *
1095
1096L<flock(3)> is not yet implemented (dummy function).
1097
1098=item *
1099
1100L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1101
1102=item *
1103
1104L<waitpid(3)>:
1105
55497cff
PP
1106 WUNTRACED
1107 Not implemented.
1108 waitpid() is not implemented for negative values of PID.
1109
d7678ab8
CS
1110=back
1111
55497cff 1112Note that C<kill -9> does not work with the current version of EMX.
615d1a09 1113
a56dbb1c 1114=item
615d1a09 1115
72ea3524 1116Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
a56dbb1c 1117of F<sh.exe> plague perl as well.
615d1a09 1118
a56dbb1c 1119In particular, uppercase letters do not work in C<[...]>-patterns with
aa689395 1120the current pdksh.
615d1a09 1121
a56dbb1c 1122=back
615d1a09 1123
55497cff
PP
1124=head2 Modifications
1125
1126Perl modifies some standard C library calls in the following ways:
1127
1128=over 9
1129
1130=item C<popen>
1131
72ea3524 1132C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
55497cff
PP
1133
1134=item C<tmpnam>
1135
1136is created using C<TMP> or C<TEMP> environment variable, via
1137C<tempnam>.
1138
1139=item C<tmpfile>
1140
72ea3524 1141If the current directory is not writable, file is created using modified
55497cff
PP
1142C<tmpnam>, so there may be a race condition.
1143
1144=item C<ctermid>
1145
1146a dummy implementation.
1147
1148=item C<stat>
1149
1150C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1151
1152=back
1153
a56dbb1c 1154=head1 Perl flavors
615d1a09 1155
72ea3524 1156Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
aa689395 1157same basket (though EMX environment tries hard to overcome this
a56dbb1c
PP
1158limitations, so the situation may somehow improve). There are 4
1159executables for Perl provided by the distribution:
615d1a09 1160
a56dbb1c 1161=head2 F<perl.exe>
615d1a09 1162
a56dbb1c
PP
1163The main workhorse. This is a chimera executable: it is compiled as an
1164C<a.out>-style executable, but is linked with C<omf>-style dynamic
aa689395
PP
1165library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1166VIO application.
a56dbb1c
PP
1167
1168It can load perl dynamic extensions, and it can fork(). Unfortunately,
aa689395
PP
1169with the current version of EMX it cannot fork() with dynamic
1170extensions loaded (may be fixed by patches to EMX).
a56dbb1c
PP
1171
1172B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1173
1174=head2 F<perl_.exe>
1175
1176This is a statically linked C<a.out>-style executable. It can fork(),
1177but cannot load dynamic Perl extensions. The supplied executable has a
1178lot of extensions prebuilt, thus there are situations when it can
1179perform tasks not possible using F<perl.exe>, like fork()ing when
aa689395 1180having some standard extension loaded. This executable is a VIO
a56dbb1c
PP
1181application.
1182
1183B<Note.> A better behaviour could be obtained from C<perl.exe> if it
1184were statically linked with standard I<Perl extensions>, but
aa689395 1185dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
a56dbb1c
PP
1186be able to fork() with standard extensions, I<and> would be able to
1187dynamically load arbitrary extensions. Some changes to Makefiles and
1188hint files should be necessary to achieve this.
1189
1190I<This is also the only executable with does not require OS/2.> The
1191friends locked into C<M$> world would appreciate the fact that this
72ea3524 1192executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
a56dbb1c
PP
1193appropriate extender. See L<"Other OSes">.
1194
1195=head2 F<perl__.exe>
1196
aa689395 1197This is the same executable as F<perl___.exe>, but it is a PM
a56dbb1c
PP
1198application.
1199
aa689395 1200B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
a56dbb1c
PP
1201application are redirected to C<nul>. However, it is possible to see
1202them if you start C<perl__.exe> from a PM program which emulates a
aa689395 1203console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
a56dbb1c
PP
1204possible> to use Perl debugger (see L<perldebug>) to debug your PM
1205application.
1206
aa689395 1207This flavor is required if you load extensions which use PM, like
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1208the forthcoming C<Perl/Tk>.
1209
1210=head2 F<perl___.exe>
1211
1212This is an C<omf>-style executable which is dynamically linked to
aa689395 1213F<perl.dll> and CRT DLL. I know no advantages of this executable
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1214over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1215that the build process is not so convoluted as with C<perl.exe>.
1216
aa689395 1217It is a VIO application.
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1218
1219=head2 Why strange names?
1220
1221Since Perl processes the C<#!>-line (cf.
1222L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1223L<perldiag/"Not a perl script">,
1224L<perldiag/"No Perl script found in input">), it should know when a
1225program I<is a Perl>. There is some naming convention which allows
1226Perl to distinguish correct lines from wrong ones. The above names are
72ea3524 1227almost the only names allowed by this convention which do not contain
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1228digits (which have absolutely different semantics).
1229
1230=head2 Why dynamic linking?
1231
1232Well, having several executables dynamically linked to the same huge
1233library has its advantages, but this would not substantiate the
1234additional work to make it compile. The reason is stupid-but-quick
1235"hard" dynamic linking used by OS/2.
1236
72ea3524
IZ
1237The address tables of DLLs are patched only once, when they are
1238loaded. The addresses of entry points into DLLs are guaranteed to be
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1239the same for all programs which use the same DLL, which reduces the
1240amount of runtime patching - once DLL is loaded, its code is
1241read-only.
1242
1243While this allows some performance advantages, this makes life
72ea3524 1244terrible for developers, since the above scheme makes it impossible
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1245for a DLL to be resolved to a symbol in the .EXE file, since this
1246would need a DLL to have different relocations tables for the
1247executables which use it.
1248
1249However, a Perl extension is forced to use some symbols from the perl
1250executable, say to know how to find the arguments provided on the perl
1251internal evaluation stack. The solution is that the main code of
1252interpreter should be contained in a DLL, and the F<.EXE> file just loads
1253this DLL into memory and supplies command-arguments.
1254
72ea3524 1255This I<greatly> increases the load time for the application (as well as
a56dbb1c 1256the number of problems during compilation). Since interpreter is in a DLL,
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1257the CRT is basically forced to reside in a DLL as well (otherwise
1258extensions would not be able to use CRT).
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1259
1260=head2 Why chimera build?
1261
aa689395 1262Current EMX environment does not allow DLLs compiled using Unixish
a56dbb1c
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1263C<a.out> format to export symbols for data. This forces C<omf>-style
1264compile of F<perl.dll>.
1265
aa689395 1266Current EMX environment does not allow F<.EXE> files compiled in
a56dbb1c
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1267C<omf> format to fork(). fork() is needed for exactly three Perl
1268operations:
1269
1270=over 4
1271
1272=item explicit fork()
1273
1274in the script, and
1275
1276=item open FH, "|-"
1277
1278=item open FH, "-|"
1279
1280opening pipes to itself.
1281
1282=back
1283
1284While these operations are not questions of life and death, a lot of
1285useful scripts use them. This forces C<a.out>-style compile of
1286F<perl.exe>.
1287
1288
1289=head1 ENVIRONMENT
1290
aa689395
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1291Here we list environment variables with are either OS/2- and DOS- and
1292Win*-specific, or are more important under OS/2 than under other OSes.
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1293
1294=head2 C<PERLLIB_PREFIX>
1295
aa689395 1296Specific for EMX port. Should have the form
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1297
1298 path1;path2
1299
1300or
1301
1302 path1 path2
1303
1304If the beginning of some prebuilt path matches F<path1>, it is
1305substituted with F<path2>.
1306
1307Should be used if the perl library is moved from the default
1308location in preference to C<PERL(5)LIB>, since this would not leave wrong
1309entries in <@INC>.
1310
1311=head2 C<PERL_BADLANG>
1312
1313If 1, perl ignores setlocale() failing. May be useful with some
1314strange I<locale>s.
1315
1316=head2 C<PERL_BADFREE>
1317
1318If 1, perl would not warn of in case of unwarranted free(). May be
1319useful in conjunction with the module DB_File, since Berkeley DB
1320memory handling code is buggy.
1321
1322=head2 C<PERL_SH_DIR>
1323
aa689395 1324Specific for EMX port. Gives the directory part of the location for
a56dbb1c
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1325F<sh.exe>.
1326
1327=head2 C<TMP> or C<TEMP>
1328
aa689395 1329Specific for EMX port. Used as storage place for temporary files, most
a56dbb1c
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1330notably C<-e> scripts.
1331
1332=head1 Evolution
1333
1334Here we list major changes which could make you by surprise.
1335
1336=head2 Priorities
1337
1338C<setpriority> and C<getpriority> are not compatible with earlier
1339ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1340
72ea3524 1341=head2 DLL name mangling
a56dbb1c
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1342
1343With the release 5.003_01 the dynamically loadable libraries
1344should be rebuilt. In particular, DLLs are now created with the names
1345which contain a checksum, thus allowing workaround for OS/2 scheme of
1346caching DLLs.
1347
1348=head2 Threading
1349
aa689395 1350As of release 5.003_01 perl is linked to multithreaded CRT
a56dbb1c
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1351DLL. Perl itself is not multithread-safe, as is not perl
1352malloc(). However, extensions may use multiple thread on their own
1353risk.
1354
aa689395 1355Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
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1356
1357=head2 Calls to external programs
1358
1359Due to a popular demand the perl external program calling has been
72ea3524 1360changed wrt Andreas Kaiser's port. I<If> perl needs to call an
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1361external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1362whatever is the override, see L<"PERL_SH_DIR">.
1363
1364Thus means that you need to get some copy of a F<sh.exe> as well (I
1365use one from pdksh). The drive F: above is set up automatically during
1366the build to a correct value on the builder machine, but is
1367overridable at runtime,
1368
1369B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1370one non-overridable shell per platform. The obvious choices for OS/2
1371are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
1372with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
aa689395
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1373100% compatibility with the scripts coming from *nix. As an added benefit
1374this works as well under DOS if you use DOS-enabled port of pdksh
1375(see L<"Prerequisites">).
a56dbb1c 1376
aa689395 1377B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
a56dbb1c
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1378via fork()/exec(), and there is I<no> functioning exec() on
1379OS/2. exec() is emulated by EMX by asyncroneous call while the caller
72ea3524 1380waits for child completion (to pretend that the C<pid> did not change). This
a56dbb1c
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1381means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1382which may lead to some resources taken from the system (even if we do
1383not count extra work needed for fork()ing).
1384
72ea3524
IZ
1385Note that this a lesser issue now when we do not spawn F<sh.exe>
1386unless needed (metachars found).
1387
1388One can always start F<cmd.exe> explicitly via
a56dbb1c
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1389
1390 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1391
72ea3524 1392If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
a56dbb1c
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1393scripts, the long-term solution proposed on p5-p is to have a directive
1394
1395 use OS2::Cmd;
1396
1397which will override system(), exec(), C<``>, and
1398C<open(,'...|')>. With current perl you may override only system(),
1399readpipe() - the explicit version of C<``>, and maybe exec(). The code
1400will substitute the one-argument call to system() by
1401C<CORE::system('cmd.exe', '/c', shift)>.
1402
1403If you have some working code for C<OS2::Cmd>, please send it to me,
1404I will include it into distribution. I have no need for such a module, so
1405cannot test it.
1406
df3ef7a9
IZ
1407=head2 Memory allocation
1408
1409Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
1410for speed, but perl is not, since its malloc is lightning-fast.
1411Unfortunately, it is also quite frivolous with memory usage as well.
1412
1413Since kitchen-top machines are usually low on memory, perl is compiled with
1414all the possible memory-saving options. This probably makes perl's
1415malloc() as greedy with memory as the neighbor's malloc(), but still
1416much quickier. Note that this is true only for a "typical" usage,
1417it is possible that the perl malloc will be worse for some very special usage.
1418
1419Combination of perl's malloc() and rigid DLL name resolution creates
1420a special problem with library functions which expect their return value to
1421be free()d by system's free(). To facilitate extensions which need to call
1422such functions, system memory-allocation functions are still available with
1423the prefix C<emx_> added. (Currently only DLL perl has this, it should
1424propagate to F<perl_.exe> shortly.)
1425
a56dbb1c
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1426=cut
1427
1428OS/2 extensions
1429~~~~~~~~~~~~~~~
72ea3524 1430I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
a56dbb1c
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1431into my ftp directory, mirrored on CPAN. I made
1432some minor changes needed to compile them by standard tools. I cannot
1433test UPM and FTP, so I will appreciate your feedback. Other extensions
1434there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1435files - and maybe some other extensions at the time you read it.
1436
1437Note that OS2 perl defines 2 pseudo-extension functions
aa689395
PP
1438OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1439L<Prebuilt methods>).
a56dbb1c
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1440
1441The -R switch of older perl is deprecated. If you need to call a REXX code
1442which needs access to variables, include the call into a REXX compartment
1443created by
1444 REXX_call {...block...};
1445
1446Two new functions are supported by REXX code,
1447 REXX_eval 'string';
1448 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1449
1450If you have some other extensions you want to share, send the code to
1451me. At least two are available: tied access to EA's, and tied access
1452to system databases.
615d1a09 1453
a56dbb1c 1454=head1 AUTHOR
615d1a09 1455
a56dbb1c 1456Ilya Zakharevich, ilya@math.ohio-state.edu
615d1a09 1457
a56dbb1c 1458=head1 SEE ALSO
615d1a09 1459
a56dbb1c 1460perl(1).
615d1a09 1461
a56dbb1c 1462=cut
615d1a09 1463