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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
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650You need to have the latest EMX development environment, the full
651GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
a56dbb1c
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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
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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 666
eb447b86
IZ
667It is reported that the following archives contain enough utils to
668build perl: gnufutil.zip, gnusutil.zip, gnututil.zip, gnused.zip,
669gnupatch.zip, gnuawk.zip, gnumake.zip and ksh527rt.zip. Note that
670all these utilities are known to be available from LEO:
671
672 ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu
a56dbb1c
PP
673
674Make sure that no copies or perl are currently running. Later steps
675of the build may fail since an older version of perl.dll loaded into
676memory may be found.
677
678Also make sure that you have F</tmp> directory on the current drive,
679and F<.> directory in your C<LIBPATH>. One may try to correct the
680latter condition by
681
682 set BEGINLIBPATH .
683
684if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
685
aa689395 686Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
a56dbb1c
PP
687script in F</emx/lib> directory.
688
aa689395 689Check that you have link386 installed. It comes standard with OS/2,
a56dbb1c
PP
690but may be not installed due to customization. If typing
691
692 link386
693
694shows you do not have it, do I<Selective install>, and choose C<Link
72ea3524 695object modules> in I<Optional system utilities/More>. If you get into
aa689395 696link386, press C<Ctrl-C>.
a56dbb1c
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697
698=head2 Getting perl source
699
72ea3524 700You need to fetch the latest perl source (including developers
a56dbb1c
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701releases). With some probability it is located in
702
703 http://www.perl.com/CPAN/src/5.0
704 http://www.perl.com/CPAN/src/5.0/unsupported
705
706If not, you may need to dig in the indices to find it in the directory
707of the current maintainer.
708
72ea3524 709Quick cycle of developers release may break the OS/2 build time to
a56dbb1c
PP
710time, looking into
711
712 http://www.perl.com/CPAN/ports/os2/ilyaz/
713
714may indicate the latest release which was publicly released by the
715maintainer. Note that the release may include some additional patches
716to apply to the current source of perl.
717
718Extract it like this
719
720 tar vzxf perl5.00409.tar.gz
721
722You may see a message about errors while extracting F<Configure>. This is
723because there is a conflict with a similarly-named file F<configure>.
724
a56dbb1c
PP
725Change to the directory of extraction.
726
727=head2 Application of the patches
728
729You need to apply the patches in F<./os2/diff.*> and
730F<./os2/POSIX.mkfifo> like this:
731
732 gnupatch -p0 < os2\POSIX.mkfifo
df3ef7a9 733 gnupatch -p0 < os2\diff.configure
a56dbb1c
PP
734
735You may also need to apply the patches supplied with the binary
736distribution of perl.
737
aa689395 738Note also that the F<db.lib> and F<db.a> from the EMX distribution
a56dbb1c 739are not suitable for multi-threaded compile (note that currently perl
aa689395
PP
740is not multithread-safe, but is compiled as multithreaded for
741compatibility with XFree86-OS/2). Get a corrected one from
a56dbb1c
PP
742
743 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
744
745=head2 Hand-editing
746
747You may look into the file F<./hints/os2.sh> and correct anything
748wrong you find there. I do not expect it is needed anywhere.
615d1a09 749
a56dbb1c 750=head2 Making
615d1a09 751
a56dbb1c 752 sh Configure -des -D prefix=f:/perllib
615d1a09 753
aa689395 754C<prefix> means: where to install the resulting perl library. Giving
a56dbb1c
PP
755correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
756see L<"PERLLIB_PREFIX">.
5243f9ae 757
a56dbb1c 758I<Ignore the message about missing C<ln>, and about C<-c> option to
aa689395 759tr>. In fact if you can trace where the latter spurious warning
a56dbb1c 760comes from, please inform me.
615d1a09 761
a56dbb1c 762Now
5243f9ae 763
a56dbb1c 764 make
5243f9ae 765
a56dbb1c
PP
766At some moment the built may die, reporting a I<version mismatch> or
767I<unable to run F<perl>>. This means that most of the build has been
768finished, and it is the time to move the constructed F<perl.dll> to
aa689395
PP
769some I<absolute> location in LIBPATH. After this is done the build
770should finish without a lot of fuss. I<One can avoid the interruption
771if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
772probably this is not needed anymore, since F<miniperl.exe> is linked
773statically now.>
615d1a09 774
a56dbb1c
PP
775Warnings which are safe to ignore: I<mkfifo() redefined> inside
776F<POSIX.c>.
615d1a09 777
a56dbb1c
PP
778=head2 Testing
779
780Now run
781
782 make test
783
72ea3524 784Some tests (4..6) should fail. Some perl invocations should end in a
a56dbb1c
PP
785segfault (system error C<SYS3175>). To get finer error reports,
786
787 cd t
aa689395 788 perl harness
a56dbb1c
PP
789
790The report you get may look like
791
792 Failed Test Status Wstat Total Fail Failed List of failed
793 ---------------------------------------------------------------
794 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
795 lib/io_pipe.t 3 768 6 ?? % ??
796 lib/io_sock.t 3 768 5 ?? % ??
797 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
72ea3524 798 Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
a56dbb1c
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799
800Note that using `make test' target two more tests may fail: C<op/exec:1>
aa689395 801because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
55497cff
PP
802that the buffers are not flushed on C<_exit> (this is a bug in the test
803which assumes that tty output is buffered).
a56dbb1c 804
aa689395 805I submitted a patch to EMX which makes it possible to fork() with EMX
72ea3524
IZ
806dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
807that soon the number of failing tests may decrease yet more.
808
df3ef7a9
IZ
809However, the test F<lib/io_udp.t> is disabled, since it never terminates, I
810do not know why. Comments/fixes welcome.
72ea3524 811
a56dbb1c
PP
812The reasons for failed tests are:
813
814=over 8
815
816=item F<io/fs.t>
817
818Checks I<file system> operations. Tests:
819
820=over 10
821
822=item 2-5, 7-11
823
824Check C<link()> and C<inode count> - nonesuch under OS/2.
825
826=item 18
827
828Checks C<atime> and C<mtime> of C<stat()> - I could not understand this test.
829
830=item 25
831
832Checks C<truncate()> on a filehandle just opened for write - I do not
833know why this should or should not work.
834
835=back
836
837=item F<lib/io_pipe.t>
838
aa689395 839Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
a56dbb1c
PP
840dynamic extension loaded - unsupported now.
841
842=item F<lib/io_sock.t>
843
aa689395 844Checks C<IO::Socket> module. Some feature of EMX - test fork()s
a56dbb1c
PP
845with dynamic extension loaded - unsupported now.
846
847=item F<op/stat.t>
848
849Checks C<stat()>. Tests:
850
851=over 4
852
853=item 3
854
855Checks C<inode count> - nonesuch under OS/2.
856
857=item 4
858
859Checks C<mtime> and C<ctime> of C<stat()> - I could not understand this test.
860
861=item 20
862
863Checks C<-x> - determined by the file extension only under OS/2.
864
865=item 35
866
867Needs F</usr/bin>.
868
869=item 39
870
871Checks C<-t> of F</dev/null>. Should not fail!
872
873=back
874
875=back
876
877In addition to errors, you should get a lot of warnings.
878
879=over 4
880
881=item A lot of `bad free'
882
883in databases related to Berkeley DB. This is a confirmed bug of
884DB. You may disable this warnings, see L<"PERL_BADFREE">.
885
886=item Process terminated by SIGTERM/SIGINT
887
888This is a standard message issued by OS/2 applications. *nix
889applications die in silence. It is considered a feature. One can
890easily disable this by appropriate sighandlers.
891
892However the test engine bleeds these message to screen in unexpected
893moments. Two messages of this kind I<should> be present during
894testing.
895
896=item F<*/sh.exe>: ln: not found
897
898=item C<ls>: /dev: No such file or directory
899
900The last two should be self-explanatory. The test suite discovers that
901the system it runs on is not I<that much> *nixish.
902
903=back
615d1a09
PP
904
905A lot of `bad free'... in databases, bug in DB confirmed on other
5243f9ae 906platforms. You may disable it by setting PERL_BADFREE environment variable
a56dbb1c 907to 1.
615d1a09 908
a56dbb1c 909=head2 Installing the built perl
615d1a09 910
a56dbb1c 911Run
615d1a09 912
a56dbb1c 913 make install
615d1a09 914
a56dbb1c
PP
915It would put the generated files into needed locations. Manually put
916F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
aa689395 917PATH, F<perl.dll> to a location on your LIBPATH.
615d1a09 918
a56dbb1c 919Run
615d1a09 920
a56dbb1c 921 make cmdscripts INSTALLCMDDIR=d:/ir/on/path
615d1a09 922
a56dbb1c 923to convert perl utilities to F<.cmd> files and put them on
aa689395 924PATH. You need to put F<.EXE>-utilities on path manually. They are
a56dbb1c
PP
925installed in C<$prefix/bin>, here C<$prefix> is what you gave to
926F<Configure>, see L<Making>.
927
928=head2 C<a.out>-style build
929
930Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
931
932 make perl_
933
934test and install by
935
936 make aout_test
937 make aout_install
938
aa689395 939Manually put F<perl_.exe> to a location on your PATH.
a56dbb1c
PP
940
941Since C<perl_> has the extensions prebuilt, it does not suffer from
72ea3524 942the I<dynamic extensions + fork()> syndrome, thus the failing tests
a56dbb1c
PP
943look like
944
945 Failed Test Status Wstat Total Fail Failed List of failed
946 ---------------------------------------------------------------
947 io/fs.t 26 11 42.31% 2-5, 7-11, 18, 25
948 op/stat.t 56 5 8.93% 3-4, 20, 35, 39
949 Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
950
951B<Note.> The build process for C<perl_> I<does not know> about all the
952dependencies, so you should make sure that anything is up-to-date,
953say, by doing
954
955 make perl.dll
956
957first.
958
959=head1 Build FAQ
960
961=head2 Some C</> became C<\> in pdksh.
962
963You have a very old pdksh. See L<Prerequisites>.
964
965=head2 C<'errno'> - unresolved external
966
967You do not have MT-safe F<db.lib>. See L<Prerequisites>.
968
aa689395 969=head2 Problems with tr
a56dbb1c 970
aa689395 971reported with very old version of tr.
a56dbb1c
PP
972
973=head2 Some problem (forget which ;-)
974
aa689395 975You have an older version of F<perl.dll> on your LIBPATH, which
a56dbb1c
PP
976broke the build of extensions.
977
978=head2 Library ... not found
979
980You did not run C<omflibs>. See L<Prerequisites>.
981
982=head2 Segfault in make
983
aa689395 984You use an old version of GNU make. See L<Prerequisites>.
a56dbb1c
PP
985
986=head1 Specific (mis)features of OS/2 port
987
988=head2 C<setpriority>, C<getpriority>
989
990Note that these functions are compatible with *nix, not with the older
991ports of '94 - 95. The priorities are absolute, go from 32 to -95,
72ea3524 992lower is quicker. 0 is the default priority.
a56dbb1c
PP
993
994=head2 C<system()>
995
996Multi-argument form of C<system()> allows an additional numeric
997argument. The meaning of this argument is described in
998L<OS2::Process>.
999
aa689395
PP
1000=head2 C<extproc> on the first line
1001
1002If the first chars of a script are C<"extproc ">, this line is treated
1003as C<#!>-line, thus all the switches on this line are processed (twice
1004if script was started via cmd.exe).
1005
a56dbb1c 1006=head2 Additional modules:
615d1a09 1007
a56dbb1c
PP
1008L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. This
1009modules provide access to additional numeric argument for C<system>,
1010to DLLs having functions with REXX signature and to REXX runtime, to
1011OS/2 databases in the F<.INI> format, and to Extended Attributes.
615d1a09 1012
72ea3524 1013Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
a56dbb1c 1014C<OS2::FTP>, are included into my ftp directory, mirrored on CPAN.
615d1a09 1015
a56dbb1c 1016=head2 Prebuilt methods:
615d1a09 1017
a56dbb1c 1018=over 4
615d1a09 1019
a56dbb1c 1020=item C<File::Copy::syscopy>
615d1a09 1021
d7678ab8 1022used by C<File::Copy::copy>, see L<File::Copy>.
615d1a09 1023
a56dbb1c 1024=item C<DynaLoader::mod2fname>
615d1a09 1025
72ea3524 1026used by C<DynaLoader> for DLL name mangling.
615d1a09 1027
a56dbb1c 1028=item C<Cwd::current_drive()>
615d1a09 1029
a56dbb1c 1030Self explanatory.
615d1a09 1031
a56dbb1c 1032=item C<Cwd::sys_chdir(name)>
615d1a09 1033
a56dbb1c 1034leaves drive as it is.
615d1a09 1035
a56dbb1c 1036=item C<Cwd::change_drive(name)>
615d1a09 1037
615d1a09 1038
a56dbb1c 1039=item C<Cwd::sys_is_absolute(name)>
615d1a09 1040
a56dbb1c 1041means has drive letter and is_rooted.
615d1a09 1042
a56dbb1c 1043=item C<Cwd::sys_is_rooted(name)>
615d1a09 1044
a56dbb1c 1045means has leading C<[/\\]> (maybe after a drive-letter:).
615d1a09 1046
a56dbb1c 1047=item C<Cwd::sys_is_relative(name)>
615d1a09 1048
a56dbb1c 1049means changes with current dir.
615d1a09 1050
a56dbb1c 1051=item C<Cwd::sys_cwd(name)>
615d1a09 1052
aa689395 1053Interface to cwd from EMX. Used by C<Cwd::cwd>.
615d1a09 1054
a56dbb1c 1055=item C<Cwd::sys_abspath(name, dir)>
615d1a09 1056
a56dbb1c
PP
1057Really really odious function to implement. Returns absolute name of
1058file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1059current dir.
615d1a09 1060
a56dbb1c 1061=item C<Cwd::extLibpath([type])
615d1a09 1062
a56dbb1c
PP
1063Get 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=item C<Cwd::extLibpath_set( path [, type ] )>
615d1a09 1068
a56dbb1c
PP
1069Set current value of extended library search path. If C<type> is
1070present and I<true>, works with END_LIBPATH, otherwise with
1071C<BEGIN_LIBPATH>.
615d1a09 1072
a56dbb1c 1073=back
615d1a09 1074
a56dbb1c
PP
1075(Note that some of these may be moved to different libraries -
1076eventually).
615d1a09 1077
615d1a09 1078
a56dbb1c 1079=head2 Misfeatures
615d1a09 1080
a56dbb1c 1081=over 4
615d1a09 1082
a56dbb1c 1083=item
615d1a09 1084
d7678ab8 1085Since L<flock(3)> is present in EMX, but is not functional, the same is
55497cff
PP
1086true for perl. Here is the list of things which may be "broken" on
1087EMX (from EMX docs):
1088
d7678ab8
CS
1089=over
1090
1091=item *
1092
1093The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not
1094implemented.
1095
1096=item *
1097
1098L<sock_init(3)> is not required and not implemented.
1099
1100=item *
1101
1102L<flock(3)> is not yet implemented (dummy function).
1103
1104=item *
1105
1106L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1107
1108=item *
1109
1110L<waitpid(3)>:
1111
55497cff
PP
1112 WUNTRACED
1113 Not implemented.
1114 waitpid() is not implemented for negative values of PID.
1115
d7678ab8
CS
1116=back
1117
55497cff 1118Note that C<kill -9> does not work with the current version of EMX.
615d1a09 1119
a56dbb1c 1120=item
615d1a09 1121
72ea3524 1122Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
a56dbb1c 1123of F<sh.exe> plague perl as well.
615d1a09 1124
a56dbb1c 1125In particular, uppercase letters do not work in C<[...]>-patterns with
aa689395 1126the current pdksh.
615d1a09 1127
a56dbb1c 1128=back
615d1a09 1129
55497cff
PP
1130=head2 Modifications
1131
1132Perl modifies some standard C library calls in the following ways:
1133
1134=over 9
1135
1136=item C<popen>
1137
72ea3524 1138C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
55497cff
PP
1139
1140=item C<tmpnam>
1141
1142is created using C<TMP> or C<TEMP> environment variable, via
1143C<tempnam>.
1144
1145=item C<tmpfile>
1146
72ea3524 1147If the current directory is not writable, file is created using modified
55497cff
PP
1148C<tmpnam>, so there may be a race condition.
1149
1150=item C<ctermid>
1151
1152a dummy implementation.
1153
1154=item C<stat>
1155
1156C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1157
1158=back
1159
a56dbb1c 1160=head1 Perl flavors
615d1a09 1161
72ea3524 1162Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
aa689395 1163same basket (though EMX environment tries hard to overcome this
a56dbb1c
PP
1164limitations, so the situation may somehow improve). There are 4
1165executables for Perl provided by the distribution:
615d1a09 1166
a56dbb1c 1167=head2 F<perl.exe>
615d1a09 1168
a56dbb1c
PP
1169The main workhorse. This is a chimera executable: it is compiled as an
1170C<a.out>-style executable, but is linked with C<omf>-style dynamic
aa689395
PP
1171library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1172VIO application.
a56dbb1c
PP
1173
1174It can load perl dynamic extensions, and it can fork(). Unfortunately,
aa689395
PP
1175with the current version of EMX it cannot fork() with dynamic
1176extensions loaded (may be fixed by patches to EMX).
a56dbb1c
PP
1177
1178B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1179
1180=head2 F<perl_.exe>
1181
1182This is a statically linked C<a.out>-style executable. It can fork(),
1183but cannot load dynamic Perl extensions. The supplied executable has a
1184lot of extensions prebuilt, thus there are situations when it can
1185perform tasks not possible using F<perl.exe>, like fork()ing when
aa689395 1186having some standard extension loaded. This executable is a VIO
a56dbb1c
PP
1187application.
1188
1189B<Note.> A better behaviour could be obtained from C<perl.exe> if it
1190were statically linked with standard I<Perl extensions>, but
aa689395 1191dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
a56dbb1c
PP
1192be able to fork() with standard extensions, I<and> would be able to
1193dynamically load arbitrary extensions. Some changes to Makefiles and
1194hint files should be necessary to achieve this.
1195
1196I<This is also the only executable with does not require OS/2.> The
1197friends locked into C<M$> world would appreciate the fact that this
72ea3524 1198executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
a56dbb1c
PP
1199appropriate extender. See L<"Other OSes">.
1200
1201=head2 F<perl__.exe>
1202
aa689395 1203This is the same executable as F<perl___.exe>, but it is a PM
a56dbb1c
PP
1204application.
1205
aa689395 1206B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
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1207application are redirected to C<nul>. However, it is possible to see
1208them if you start C<perl__.exe> from a PM program which emulates a
aa689395 1209console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
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1210possible> to use Perl debugger (see L<perldebug>) to debug your PM
1211application.
1212
aa689395 1213This flavor is required if you load extensions which use PM, like
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1214the forthcoming C<Perl/Tk>.
1215
1216=head2 F<perl___.exe>
1217
1218This is an C<omf>-style executable which is dynamically linked to
aa689395 1219F<perl.dll> and CRT DLL. I know no advantages of this executable
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1220over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1221that the build process is not so convoluted as with C<perl.exe>.
1222
aa689395 1223It is a VIO application.
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1224
1225=head2 Why strange names?
1226
1227Since Perl processes the C<#!>-line (cf.
1228L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1229L<perldiag/"Not a perl script">,
1230L<perldiag/"No Perl script found in input">), it should know when a
1231program I<is a Perl>. There is some naming convention which allows
1232Perl to distinguish correct lines from wrong ones. The above names are
72ea3524 1233almost the only names allowed by this convention which do not contain
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1234digits (which have absolutely different semantics).
1235
1236=head2 Why dynamic linking?
1237
1238Well, having several executables dynamically linked to the same huge
1239library has its advantages, but this would not substantiate the
1240additional work to make it compile. The reason is stupid-but-quick
1241"hard" dynamic linking used by OS/2.
1242
72ea3524
IZ
1243The address tables of DLLs are patched only once, when they are
1244loaded. The addresses of entry points into DLLs are guaranteed to be
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1245the same for all programs which use the same DLL, which reduces the
1246amount of runtime patching - once DLL is loaded, its code is
1247read-only.
1248
1249While this allows some performance advantages, this makes life
72ea3524 1250terrible for developers, since the above scheme makes it impossible
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1251for a DLL to be resolved to a symbol in the .EXE file, since this
1252would need a DLL to have different relocations tables for the
1253executables which use it.
1254
1255However, a Perl extension is forced to use some symbols from the perl
1256executable, say to know how to find the arguments provided on the perl
1257internal evaluation stack. The solution is that the main code of
1258interpreter should be contained in a DLL, and the F<.EXE> file just loads
1259this DLL into memory and supplies command-arguments.
1260
72ea3524 1261This I<greatly> increases the load time for the application (as well as
a56dbb1c 1262the number of problems during compilation). Since interpreter is in a DLL,
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1263the CRT is basically forced to reside in a DLL as well (otherwise
1264extensions would not be able to use CRT).
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1265
1266=head2 Why chimera build?
1267
aa689395 1268Current EMX environment does not allow DLLs compiled using Unixish
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1269C<a.out> format to export symbols for data. This forces C<omf>-style
1270compile of F<perl.dll>.
1271
aa689395 1272Current EMX environment does not allow F<.EXE> files compiled in
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1273C<omf> format to fork(). fork() is needed for exactly three Perl
1274operations:
1275
1276=over 4
1277
1278=item explicit fork()
1279
1280in the script, and
1281
1282=item open FH, "|-"
1283
1284=item open FH, "-|"
1285
1286opening pipes to itself.
1287
1288=back
1289
1290While these operations are not questions of life and death, a lot of
1291useful scripts use them. This forces C<a.out>-style compile of
1292F<perl.exe>.
1293
1294
1295=head1 ENVIRONMENT
1296
aa689395
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1297Here we list environment variables with are either OS/2- and DOS- and
1298Win*-specific, or are more important under OS/2 than under other OSes.
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1299
1300=head2 C<PERLLIB_PREFIX>
1301
aa689395 1302Specific for EMX port. Should have the form
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1303
1304 path1;path2
1305
1306or
1307
1308 path1 path2
1309
1310If the beginning of some prebuilt path matches F<path1>, it is
1311substituted with F<path2>.
1312
1313Should be used if the perl library is moved from the default
1314location in preference to C<PERL(5)LIB>, since this would not leave wrong
eb447b86
IZ
1315entries in @INC. Say, if the compiled version of perl looks for @INC
1316in F<f:/perllib/lib>, and you want to install the library in
1317F<h:/opt/gnu>, do
1318
1319 set PERLLIB_PREFIX=f:/perllib/lib;h:/opt/gnu
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1320
1321=head2 C<PERL_BADLANG>
1322
1323If 1, perl ignores setlocale() failing. May be useful with some
1324strange I<locale>s.
1325
1326=head2 C<PERL_BADFREE>
1327
1328If 1, perl would not warn of in case of unwarranted free(). May be
1329useful in conjunction with the module DB_File, since Berkeley DB
1330memory handling code is buggy.
1331
1332=head2 C<PERL_SH_DIR>
1333
aa689395 1334Specific for EMX port. Gives the directory part of the location for
a56dbb1c
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1335F<sh.exe>.
1336
1337=head2 C<TMP> or C<TEMP>
1338
aa689395 1339Specific for EMX port. Used as storage place for temporary files, most
a56dbb1c
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1340notably C<-e> scripts.
1341
1342=head1 Evolution
1343
1344Here we list major changes which could make you by surprise.
1345
1346=head2 Priorities
1347
1348C<setpriority> and C<getpriority> are not compatible with earlier
1349ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1350
72ea3524 1351=head2 DLL name mangling
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1352
1353With the release 5.003_01 the dynamically loadable libraries
1354should be rebuilt. In particular, DLLs are now created with the names
1355which contain a checksum, thus allowing workaround for OS/2 scheme of
1356caching DLLs.
1357
1358=head2 Threading
1359
aa689395 1360As of release 5.003_01 perl is linked to multithreaded CRT
a56dbb1c
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1361DLL. Perl itself is not multithread-safe, as is not perl
1362malloc(). However, extensions may use multiple thread on their own
1363risk.
1364
aa689395 1365Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
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1366
1367=head2 Calls to external programs
1368
1369Due to a popular demand the perl external program calling has been
72ea3524 1370changed wrt Andreas Kaiser's port. I<If> perl needs to call an
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1371external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1372whatever is the override, see L<"PERL_SH_DIR">.
1373
1374Thus means that you need to get some copy of a F<sh.exe> as well (I
1375use one from pdksh). The drive F: above is set up automatically during
1376the build to a correct value on the builder machine, but is
1377overridable at runtime,
1378
1379B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1380one non-overridable shell per platform. The obvious choices for OS/2
1381are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
1382with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
aa689395
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1383100% compatibility with the scripts coming from *nix. As an added benefit
1384this works as well under DOS if you use DOS-enabled port of pdksh
1385(see L<"Prerequisites">).
a56dbb1c 1386
aa689395 1387B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
a56dbb1c
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1388via fork()/exec(), and there is I<no> functioning exec() on
1389OS/2. exec() is emulated by EMX by asyncroneous call while the caller
72ea3524 1390waits for child completion (to pretend that the C<pid> did not change). This
a56dbb1c
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1391means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1392which may lead to some resources taken from the system (even if we do
1393not count extra work needed for fork()ing).
1394
72ea3524
IZ
1395Note that this a lesser issue now when we do not spawn F<sh.exe>
1396unless needed (metachars found).
1397
1398One can always start F<cmd.exe> explicitly via
a56dbb1c
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1399
1400 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1401
72ea3524 1402If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
a56dbb1c
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1403scripts, the long-term solution proposed on p5-p is to have a directive
1404
1405 use OS2::Cmd;
1406
1407which will override system(), exec(), C<``>, and
1408C<open(,'...|')>. With current perl you may override only system(),
1409readpipe() - the explicit version of C<``>, and maybe exec(). The code
1410will substitute the one-argument call to system() by
1411C<CORE::system('cmd.exe', '/c', shift)>.
1412
1413If you have some working code for C<OS2::Cmd>, please send it to me,
1414I will include it into distribution. I have no need for such a module, so
1415cannot test it.
1416
df3ef7a9
IZ
1417=head2 Memory allocation
1418
1419Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
1420for speed, but perl is not, since its malloc is lightning-fast.
1421Unfortunately, it is also quite frivolous with memory usage as well.
1422
1423Since kitchen-top machines are usually low on memory, perl is compiled with
1424all the possible memory-saving options. This probably makes perl's
1425malloc() as greedy with memory as the neighbor's malloc(), but still
1426much quickier. Note that this is true only for a "typical" usage,
1427it is possible that the perl malloc will be worse for some very special usage.
1428
1429Combination of perl's malloc() and rigid DLL name resolution creates
1430a special problem with library functions which expect their return value to
1431be free()d by system's free(). To facilitate extensions which need to call
1432such functions, system memory-allocation functions are still available with
1433the prefix C<emx_> added. (Currently only DLL perl has this, it should
1434propagate to F<perl_.exe> shortly.)
1435
a56dbb1c
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1436=cut
1437
1438OS/2 extensions
1439~~~~~~~~~~~~~~~
72ea3524 1440I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
a56dbb1c
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1441into my ftp directory, mirrored on CPAN. I made
1442some minor changes needed to compile them by standard tools. I cannot
1443test UPM and FTP, so I will appreciate your feedback. Other extensions
1444there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1445files - and maybe some other extensions at the time you read it.
1446
1447Note that OS2 perl defines 2 pseudo-extension functions
aa689395
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1448OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1449L<Prebuilt methods>).
a56dbb1c
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1450
1451The -R switch of older perl is deprecated. If you need to call a REXX code
1452which needs access to variables, include the call into a REXX compartment
1453created by
1454 REXX_call {...block...};
1455
1456Two new functions are supported by REXX code,
1457 REXX_eval 'string';
1458 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1459
1460If you have some other extensions you want to share, send the code to
1461me. At least two are available: tied access to EA's, and tied access
1462to system databases.
615d1a09 1463
a56dbb1c 1464=head1 AUTHOR
615d1a09 1465
a56dbb1c 1466Ilya Zakharevich, ilya@math.ohio-state.edu
615d1a09 1467
a56dbb1c 1468=head1 SEE ALSO
615d1a09 1469
a56dbb1c 1470perl(1).
615d1a09 1471
a56dbb1c 1472=cut
615d1a09 1473