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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
df3ef7a9 114 - Memory allocation
ec40c0cd 115 - Threads
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116 AUTHOR
117 SEE ALSO
abe67105 118
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119=head1 DESCRIPTION
120
121=head2 Target
122
123The target is to make OS/2 the best supported platform for
72ea3524 124using/building/developing Perl and I<Perl applications>, as well as
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125make Perl the best language to use under OS/2. The secondary target is
126to try to make this work under DOS and Win* as well (but not B<too> hard).
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127
128The current state is quite close to this target. Known limitations:
129
130=over 5
131
132=item *
133
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134Some *nix programs use fork() a lot; with the mostly useful flavors of perl
135for OS/2 (there are several built simultaneously) this is supported;
136some flavors do not. Using fork() after I<use>ing dynamically loading
137extensions would not work with very old versions of EMX.
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138
139=item *
140
141You need a separate perl executable F<perl__.exe> (see L<perl__.exe>)
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142if you want to use PM code in your application (as Perl/Tk or OpenGL
143Perl modules do) without having a text-mode window present.
144
145While using the standard F<perl.exe> from a text-mode window is possible
146too, I have seen cases when this causes degradation of the system stability.
147Using F<perl__.exe> avoids such a degradation.
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148
149=item *
150
aa689395 151There is no simple way to access WPS objects. The only way I know
a56dbb1c 152is via C<OS2::REXX> extension (see L<OS2::REXX>), and we do not have access to
aa689395 153convenience methods of Object-REXX. (Is it possible at all? I know
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154of no Object-REXX API.) The C<SOM> extension (currently in alpha-text)
155may eventually remove this shortcoming.
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156
157=back
158
159Please keep this list up-to-date by informing me about other items.
160
161=head2 Other OSes
162
aa689395 163Since OS/2 port of perl uses a remarkable EMX environment, it can
3998488b 164run (and build extensions, and - possibly - be built itself) under any
a56dbb1c 165environment which can run EMX. The current list is DOS,
72ea3524 166DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors,
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167only one works, see L<"perl_.exe">.
168
169Note that not all features of Perl are available under these
170environments. This depends on the features the I<extender> - most
aa689395 171probably RSX - decided to implement.
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172
173Cf. L<Prerequisites>.
174
175=head2 Prerequisites
176
177=over 6
178
aa689395 179=item EMX
a56dbb1c 180
aa689395 181EMX runtime is required (may be substituted by RSX). Note that
55497cff 182it is possible to make F<perl_.exe> to run under DOS without any
72ea3524 183external support by binding F<emx.exe>/F<rsx.exe> to it, see L<emxbind>. Note
aa689395 184that under DOS for best results one should use RSX runtime, which
55497cff 185has much more functions working (like C<fork>, C<popen> and so on). In
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186fact RSX is required if there is no VCPI present. Note the
187RSX requires DPMI.
a56dbb1c 188
884335e8 189Only the latest runtime is supported, currently C<0.9d fix 03>. Perl may run
aa689395 190under earlier versions of EMX, but this is not tested.
a56dbb1c 191
aa689395 192One can get different parts of EMX from, say
a56dbb1c 193
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194 http://www.leo.org/pub/comp/os/os2/leo/gnu/emx+gcc/
195 http://powerusersbbs.com/pub/os2/dev/ [EMX+GCC Development]
196 http://hobbes.nmsu.edu/pub/os2/dev/emx/v0.9d/
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197
198The runtime component should have the name F<emxrt.zip>.
199
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200B<NOTE>. It is enough to have F<emx.exe>/F<rsx.exe> on your path. One
201does not need to specify them explicitly (though this
202
203 emx perl_.exe -de 0
204
205will work as well.)
206
aa689395 207=item RSX
a56dbb1c 208
aa689395 209To run Perl on DPMI platforms one needs RSX runtime. This is
72ea3524 210needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see
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211L<"Other OSes">). RSX would not work with VCPI
212only, as EMX would, it requires DMPI.
55497cff 213
aa689395 214Having RSX and the latest F<sh.exe> one gets a fully functional
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215B<*nix>-ish environment under DOS, say, C<fork>, C<``> and
216pipe-C<open> work. In fact, MakeMaker works (for static build), so one
217can have Perl development environment under DOS.
a56dbb1c 218
aa689395 219One can get RSX from, say
a56dbb1c 220
d7678ab8 221 ftp://ftp.cdrom.com/pub/os2/emx09c/contrib
a56dbb1c 222 ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc
d7678ab8 223 ftp://ftp.leo.org/pub/comp/os/os2/leo/devtools/emx+gcc/contrib
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224
225Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
226
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227The latest F<sh.exe> with DOS hooks is available in
228
229 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/
55497cff 230
3998488b 231as F<sh_dos.zip> or under similar names starting with C<sh>, C<pdksh> etc.
55497cff 232
aa689395 233=item HPFS
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234
235Perl does not care about file systems, but to install the whole perl
236library intact one needs a file system which supports long file names.
237
238Note that if you do not plan to build the perl itself, it may be
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239possible to fool EMX to truncate file names. This is not supported,
240read EMX docs to see how to do it.
241
242=item pdksh
243
244To start external programs with complicated command lines (like with
245pipes in between, and/or quoting of arguments), Perl uses an external
3998488b 246shell. With EMX port such shell should be named F<sh.exe>, and located
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247either in the wired-in-during-compile locations (usually F<F:/bin>),
248or in configurable location (see L<"PERL_SH_DIR">).
249
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250For best results use EMX pdksh. The standard binary (5.2.14 or later) runs
251under DOS (with L<RSX>) as well, see
aa689395 252
3998488b 253 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/
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254
255=back
256
aa689395 257=head2 Starting Perl programs under OS/2 (and DOS and...)
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258
259Start your Perl program F<foo.pl> with arguments C<arg1 arg2 arg3> the
260same way as on any other platform, by
261
262 perl foo.pl arg1 arg2 arg3
263
264If you want to specify perl options C<-my_opts> to the perl itself (as
265opposed to to your program), use
266
267 perl -my_opts foo.pl arg1 arg2 arg3
268
aa689395 269Alternately, if you use OS/2-ish shell, like CMD or 4os2, put
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270the following at the start of your perl script:
271
aa689395 272 extproc perl -S -my_opts
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273
274rename your program to F<foo.cmd>, and start it by typing
275
276 foo arg1 arg2 arg3
277
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278Note that because of stupid OS/2 limitations the full path of the perl
279script is not available when you use C<extproc>, thus you are forced to
3998488b 280use C<-S> perl switch, and your script should be on the C<PATH>. As a plus
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281side, if you know a full path to your script, you may still start it
282with
283
aa689395 284 perl ../../blah/foo.cmd arg1 arg2 arg3
a56dbb1c 285
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286(note that the argument C<-my_opts> is taken care of by the C<extproc> line
287in your script, see L<C<extproc> on the first line>).
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288
289To understand what the above I<magic> does, read perl docs about C<-S>
aa689395 290switch - see L<perlrun>, and cmdref about C<extproc>:
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291
292 view perl perlrun
293 man perlrun
294 view cmdref extproc
295 help extproc
296
297or whatever method you prefer.
298
72ea3524 299There are also endless possibilities to use I<executable extensions> of
aa689395 3004os2, I<associations> of WPS and so on... However, if you use
a56dbb1c 301*nixish shell (like F<sh.exe> supplied in the binary distribution),
72ea3524 302you need to follow the syntax specified in L<perlrun/"Switches">.
a56dbb1c 303
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304Note that B<-S> switch enables a search with additional extensions
305F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well.
306
aa689395 307=head2 Starting OS/2 (and DOS) programs under Perl
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308
309This is what system() (see L<perlfunc/system>), C<``> (see
310L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
311are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
312do).
313
314Note however that to use some of these operators you need to have a
aa689395 315sh-syntax shell installed (see L<"Pdksh">,
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316L<"Frequently asked questions">), and perl should be able to find it
317(see L<"PERL_SH_DIR">).
318
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319The cases when the shell is used are:
320
321=over
322
323=item 1
324
325One-argument system() (see L<perlfunc/system>), exec() (see L<perlfunc/exec>)
326with redirection or shell meta-characters;
327
328=item 2
329
330Pipe-open (see L<perlfunc/open>) with the command which contains redirection
331or shell meta-characters;
332
333=item 3
334
335Backticks C<``> (see L<perlop/"I/O Operators">) with the command which contains
336redirection or shell meta-characters;
337
338=item 4
339
340If the executable called by system()/exec()/pipe-open()/C<``> is a script
341with the "magic" C<#!> line or C<extproc> line which specifies shell;
342
343=item 5
344
345If the executable called by system()/exec()/pipe-open()/C<``> is a script
346without "magic" line, and C<$ENV{EXECSHELL}> is set to shell;
347
348=item 6
349
350If the executable called by system()/exec()/pipe-open()/C<``> is not
351found;
352
353=item 7
354
355For globbing (see L<perlfunc/glob>, L<perlop/"I/O Operators">).
356
357=back
358
359For the sake of speed for a common case, in the above algorithms
360backslashes in the command name are not considered as shell metacharacters.
361
362Perl starts scripts which begin with cookies
363C<extproc> or C<#!> directly, without an intervention of shell. Perl uses the
364same algorithm to find the executable as F<pdksh>: if the path
365on C<#!> line does not work, and contains C</>, then the executable
366is searched in F<.> and on C<PATH>. To find arguments for these scripts
367Perl uses a different algorithm than F<pdksh>: up to 3 arguments are
368recognized, and trailing whitespace is stripped.
369
370If a script
371does not contain such a cooky, then to avoid calling F<sh.exe>, Perl uses
372the same algorithm as F<pdksh>: if C<$ENV{EXECSHELL}> is set, the
373script is given as the first argument to this command, if not set, then
374C<$ENV{COMSPEC} /c> is used (or a hardwired guess if C<$ENV{COMSPEC}> is
375not set).
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376
377If starting scripts directly, Perl will use exactly the same algorithm as for
378the search of script given by B<-S> command-line option: it will look in
379the current directory, then on components of C<$ENV{PATH}> using the
380following order of appended extensions: no extension, F<.cmd>, F<.btm>,
381F<.bat>, F<.pl>.
382
383Note that Perl will start to look for scripts only if OS/2 cannot start the
384specified application, thus C<system 'blah'> will not look for a script if
385there is an executable file F<blah.exe> I<anywhere> on C<PATH>.
386
387Note also that executable files on OS/2 can have an arbitrary extension,
388but F<.exe> will be automatically appended if no dot is present in the name.
389The workaround as as simple as that: since F<blah.> and F<blah> denote the
390same file, to start an executable residing in file F<n:/bin/blah> (no
3998488b 391extension) give an argument C<n:/bin/blah.> (dot appended) to system().
491527d0 392
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393Perl will correctly start PM programs from VIO (=text-mode) Perl process;
394the opposite is not true: when you start a non-PM program from a PM
395Perl process, it would not run it in a separate session. If a separate
396session is desired, either ensure
397that shell will be used, as in C<system 'cmd /c myprog'>, or start it using
491527d0 398optional arguments to system() documented in C<OS2::Process> module. This
3998488b 399is considered to be a feature.
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400
401=head1 Frequently asked questions
402
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403=head2 "It does not work"
404
405Perl binary distributions come with a F<testperl.cmd> script which tries
406to detect common problems with misconfigured installations. There is a
407pretty large chance it will discover which step of the installation you
408managed to goof. C<;-)>
409
72ea3524 410=head2 I cannot run external programs
a56dbb1c 411
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412=over 4
413
13a2d996 414=item *
55497cff 415
a56dbb1c 416Did you run your programs with C<-w> switch? See
aa689395 417L<Starting OS/2 (and DOS) programs under Perl>.
a56dbb1c 418
13a2d996 419=item *
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420
421Do you try to run I<internal> shell commands, like C<`copy a b`>
422(internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You
72ea3524 423need to specify your shell explicitly, like C<`cmd /c copy a b`>,
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424since Perl cannot deduce which commands are internal to your shell.
425
426=back
427
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428=head2 I cannot embed perl into my program, or use F<perl.dll> from my
429program.
430
431=over 4
432
aa689395 433=item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
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434
435If not, you need to build a stand-alone DLL for perl. Contact me, I
436did it once. Sockets would not work, as a lot of other stuff.
437
aa689395 438=item Did you use L<ExtUtils::Embed>?
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439
440I had reports it does not work. Somebody would need to fix it.
441
442=back
443
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444=head2 C<``> and pipe-C<open> do not work under DOS.
445
72ea3524 446This may a variant of just L<"I cannot run external programs">, or a
aa689395 447deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
72ea3524 448for these commands to work, and you may need a port of F<sh.exe> which
55497cff 449understands command arguments. One of such ports is listed in
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450L<"Prerequisites"> under RSX. Do not forget to set variable
451C<L<"PERL_SH_DIR">> as well.
452
453DPMI is required for RSX.
454
455=head2 Cannot start C<find.exe "pattern" file>
55497cff 456
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457Use one of
458
459 system 'cmd', '/c', 'find "pattern" file';
460 `cmd /c 'find "pattern" file'`
461
462This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
463C<perl.exe>, but this is a price to pay if you want to use
464non-conforming program. In fact F<find.exe> cannot be started at all
3998488b 465using C library API only. Otherwise the following command-lines would be
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466equivalent:
467
468 find "pattern" file
469 find pattern file
55497cff 470
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471=head1 INSTALLATION
472
473=head2 Automatic binary installation
474
3998488b 475The most convenient way of installing a binary distribution of perl is via perl installer
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476F<install.exe>. Just follow the instructions, and 99% of the
477installation blues would go away.
478
479Note however, that you need to have F<unzip.exe> on your path, and
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480EMX environment I<running>. The latter means that if you just
481installed EMX, and made all the needed changes to F<Config.sys>,
482you may need to reboot in between. Check EMX runtime by running
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483
484 emxrev
485
486A folder is created on your desktop which contains some useful
487objects.
488
489B<Things not taken care of by automatic binary installation:>
490
491=over 15
492
493=item C<PERL_BADLANG>
494
495may be needed if you change your codepage I<after> perl installation,
aa689395 496and the new value is not supported by EMX. See L<"PERL_BADLANG">.
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497
498=item C<PERL_BADFREE>
499
500see L<"PERL_BADFREE">.
501
502=item F<Config.pm>
503
504This file resides somewhere deep in the location you installed your
505perl library, find it out by
506
507 perl -MConfig -le "print $INC{'Config.pm'}"
508
509While most important values in this file I<are> updated by the binary
510installer, some of them may need to be hand-edited. I know no such
511data, please keep me informed if you find one.
512
513=back
514
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515B<NOTE>. Because of a typo the binary installer of 5.00305
516would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
517remove this variable and put C<L<PERL_SH_DIR>> instead.
518
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519=head2 Manual binary installation
520
72ea3524 521As of version 5.00305, OS/2 perl binary distribution comes split
a56dbb1c 522into 11 components. Unfortunately, to enable configurable binary
aa689395 523installation, the file paths in the zip files are not absolute, but
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524relative to some directory.
525
526Note that the extraction with the stored paths is still necessary
aa689395 527(default with unzip, specify C<-d> to pkunzip). However, you
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528need to know where to extract the files. You need also to manually
529change entries in F<Config.sys> to reflect where did you put the
72ea3524 530files. Note that if you have some primitive unzipper (like
aa689395 531pkunzip), you may get a lot of warnings/errors during
72ea3524 532unzipping. Upgrade to C<(w)unzip>.
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533
534Below is the sample of what to do to reproduce the configuration on my
535machine:
536
537=over 3
538
539=item Perl VIO and PM executables (dynamically linked)
540
541 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
542 unzip perl_exc.zip *.dll -d f:/emx.add/dll
543
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544(have the directories with C<*.exe> on PATH, and C<*.dll> on
545LIBPATH);
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546
547=item Perl_ VIO executable (statically linked)
548
549 unzip perl_aou.zip -d f:/emx.add/bin
550
aa689395 551(have the directory on PATH);
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552
553=item Executables for Perl utilities
554
555 unzip perl_utl.zip -d f:/emx.add/bin
556
aa689395 557(have the directory on PATH);
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558
559=item Main Perl library
560
561 unzip perl_mlb.zip -d f:/perllib/lib
562
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563If this directory is exactly the same as the prefix which was compiled
564into F<perl.exe>, you do not need to change
565anything. However, for perl to find the library if you use a different
566path, you need to
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567C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
568
569=item Additional Perl modules
570
3998488b 571 unzip perl_ste.zip -d f:/perllib/lib/site_perl/5.8.3/
a56dbb1c 572
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573Same remark as above applies. Additionally, if this directory is not
574one of directories on @INC (and @INC is influenced by C<PERLLIB_PREFIX>), you
575need to put this
a56dbb1c
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576directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
577variable. Do not use C<PERL5LIB> unless you have it set already. See
3998488b 578L<perl/"ENVIRONMENT">.
a56dbb1c
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579
580=item Tools to compile Perl modules
581
582 unzip perl_blb.zip -d f:/perllib/lib
583
3998488b 584Same remark as for F<perl_ste.zip>.
a56dbb1c
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585
586=item Manpages for Perl and utilities
587
588 unzip perl_man.zip -d f:/perllib/man
589
590This directory should better be on C<MANPATH>. You need to have a
aa689395 591working man to access these files.
a56dbb1c
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592
593=item Manpages for Perl modules
594
595 unzip perl_mam.zip -d f:/perllib/man
596
597This directory should better be on C<MANPATH>. You need to have a
aa689395 598working man to access these files.
a56dbb1c
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599
600=item Source for Perl documentation
601
602 unzip perl_pod.zip -d f:/perllib/lib
603
3998488b 604This is used by the C<perldoc> program (see L<perldoc>), and may be used to
aa689395 605generate HTML documentation usable by WWW browsers, and
a56dbb1c
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606documentation in zillions of other formats: C<info>, C<LaTeX>,
607C<Acrobat>, C<FrameMaker> and so on.
608
aa689395 609=item Perl manual in F<.INF> format
a56dbb1c
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610
611 unzip perl_inf.zip -d d:/os2/book
612
613This directory should better be on C<BOOKSHELF>.
614
615=item Pdksh
616
617 unzip perl_sh.zip -d f:/bin
618
72ea3524 619This is used by perl to run external commands which explicitly
a56dbb1c
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620require shell, like the commands using I<redirection> and I<shell
621metacharacters>. It is also used instead of explicit F</bin/sh>.
622
623Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
624the above location.
625
aa689395 626B<Note.> It may be possible to use some other sh-compatible shell
3998488b 627(file globbing - if done via shell - may break).
a56dbb1c
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628
629=back
630
631After you installed the components you needed and updated the
632F<Config.sys> correspondingly, you need to hand-edit
633F<Config.pm>. This file resides somewhere deep in the location you
634installed your perl library, find it out by
635
636 perl -MConfig -le "print $INC{'Config.pm'}"
637
638You need to correct all the entries which look like file paths (they
639currently start with C<f:/>).
640
641=head2 B<Warning>
642
643The automatic and manual perl installation leave precompiled paths
644inside perl executables. While these paths are overwriteable (see
645L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
646binary editing of paths inside the executables/DLLs.
647
648=head1 Accessing documentation
649
650Depending on how you built/installed perl you may have (otherwise
651identical) Perl documentation in the following formats:
652
653=head2 OS/2 F<.INF> file
654
aa689395 655Most probably the most convenient form. Under OS/2 view it as
a56dbb1c
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656
657 view perl
658 view perl perlfunc
659 view perl less
660 view perl ExtUtils::MakeMaker
661
662(currently the last two may hit a wrong location, but this may improve
aa689395 663soon). Under Win* see L<"SYNOPSIS">.
a56dbb1c
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664
665If you want to build the docs yourself, and have I<OS/2 toolkit>, run
666
667 pod2ipf > perl.ipf
668
669in F</perllib/lib/pod> directory, then
670
671 ipfc /inf perl.ipf
672
673(Expect a lot of errors during the both steps.) Now move it on your
674BOOKSHELF path.
675
676=head2 Plain text
677
678If you have perl documentation in the source form, perl utilities
aa689395 679installed, and GNU groff installed, you may use
a56dbb1c
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680
681 perldoc perlfunc
682 perldoc less
683 perldoc ExtUtils::MakeMaker
684
72ea3524 685to access the perl documentation in the text form (note that you may get
a56dbb1c
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686better results using perl manpages).
687
688Alternately, try running pod2text on F<.pod> files.
689
690=head2 Manpages
691
aa689395 692If you have man installed on your system, and you installed perl
a56dbb1c 693manpages, use something like this:
5243f9ae 694
5243f9ae
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695 man perlfunc
696 man 3 less
697 man ExtUtils.MakeMaker
5243f9ae 698
a56dbb1c
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699to access documentation for different components of Perl. Start with
700
701 man perl
702
703Note that dot (F<.>) is used as a package separator for documentation
704for packages, and as usual, sometimes you need to give the section - C<3>
705above - to avoid shadowing by the I<less(1) manpage>.
706
707Make sure that the directory B<above> the directory with manpages is
708on our C<MANPATH>, like this
709
710 set MANPATH=c:/man;f:/perllib/man
711
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712for Perl manpages in C<f:/perllib/man/man1/> etc.
713
aa689395 714=head2 HTML
a56dbb1c
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715
716If you have some WWW browser available, installed the Perl
717documentation in the source form, and Perl utilities, you can build
aa689395 718HTML docs. Cd to directory with F<.pod> files, and do like this
a56dbb1c
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719
720 cd f:/perllib/lib/pod
5243f9ae 721 pod2html
5243f9ae 722
a56dbb1c
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723After this you can direct your browser the file F<perl.html> in this
724directory, and go ahead with reading docs, like this:
5243f9ae 725
a56dbb1c 726 explore file:///f:/perllib/lib/pod/perl.html
5243f9ae 727
aa689395 728Alternatively you may be able to get these docs prebuilt from CPAN.
5243f9ae 729
aa689395 730=head2 GNU C<info> files
bb14ff96 731
aa689395 732Users of Emacs would appreciate it very much, especially with
a56dbb1c
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733C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
734or, alternately, prebuilt info pages.
615d1a09 735
a56dbb1c
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736=head2 F<.PDF> files
737
738for C<Acrobat> are available on CPAN (for slightly old version of
739perl).
740
741=head2 C<LaTeX> docs
742
743can be constructed using C<pod2latex>.
744
745=head1 BUILD
746
747Here we discuss how to build Perl under OS/2. There is an alternative
b3b6085d 748(but maybe older) view on http://www.shadow.net/~troc/os2perl.html
a56dbb1c 749
3998488b
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750=head2 The short story
751
752Assume that you are a seasoned porter, so are sure that all the necessary
753tools are already present on your system, and you know how to get the Perl
754source distribution. Untar it, change to the extract directory, and
755
756 gnupatch -p0 < os2\diff.configure
757 sh Configure -des -D prefix=f:/perllib
758 make
759 make test
760 make install
761 make aout_test
762 make aout_install
763
764This puts the executables in f:/perllib/bin. Manually move them to the
765C<PATH>, manually move the built F<perl*.dll> to C<LIBPATH> (here F<*> is
766a not-very-meaningful hex checksum), and run
767
768 make installcmd INSTALLCMDDIR=d:/ir/on/path
769
770What follows is a detailed guide through these steps.
771
a56dbb1c
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772=head2 Prerequisites
773
aa689395
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774You need to have the latest EMX development environment, the full
775GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
a56dbb1c
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776earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
777check use
778
779 find --version
780 sort --version
781
782). You need the latest version of F<pdksh> installed as F<sh.exe>.
783
2c2e0e8c
IZ
784Check that you have B<BSD> libraries and headers installed, and -
785optionally - Berkeley DB headers and libraries, and crypt.
786
a56dbb1c
PP
787Possible locations to get this from are
788
d7678ab8 789 ftp://hobbes.nmsu.edu/os2/unix/
a56dbb1c
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790 ftp://ftp.cdrom.com/pub/os2/unix/
791 ftp://ftp.cdrom.com/pub/os2/dev32/
d7678ab8 792 ftp://ftp.cdrom.com/pub/os2/emx09c/
a56dbb1c 793
eb447b86 794It is reported that the following archives contain enough utils to
3998488b
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795build perl: F<gnufutil.zip>, F<gnusutil.zip>, F<gnututil.zip>, F<gnused.zip>,
796F<gnupatch.zip>, F<gnuawk.zip>, F<gnumake.zip>, F<bsddev.zip> and
797F<ksh527rt.zip> (or a later version). Note that all these utilities are
798known to be available from LEO:
eb447b86
IZ
799
800 ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu
a56dbb1c 801
3998488b
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802If you have I<exactly the same version of Perl> installed already,
803make sure that no copies or perl are currently running. Later steps
804of the build may fail since an older version of F<perl.dll> loaded into
a56dbb1c
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805memory may be found.
806
807Also make sure that you have F</tmp> directory on the current drive,
808and F<.> directory in your C<LIBPATH>. One may try to correct the
809latter condition by
810
811 set BEGINLIBPATH .
812
813if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
814
aa689395 815Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
a56dbb1c
PP
816script in F</emx/lib> directory.
817
aa689395 818Check that you have link386 installed. It comes standard with OS/2,
a56dbb1c
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819but may be not installed due to customization. If typing
820
821 link386
822
823shows you do not have it, do I<Selective install>, and choose C<Link
72ea3524 824object modules> in I<Optional system utilities/More>. If you get into
3998488b 825link386 prompts, press C<Ctrl-C> to exit.
a56dbb1c
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826
827=head2 Getting perl source
828
72ea3524 829You need to fetch the latest perl source (including developers
a56dbb1c
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830releases). With some probability it is located in
831
832 http://www.perl.com/CPAN/src/5.0
833 http://www.perl.com/CPAN/src/5.0/unsupported
834
835If not, you may need to dig in the indices to find it in the directory
836of the current maintainer.
837
72ea3524 838Quick cycle of developers release may break the OS/2 build time to
a56dbb1c
PP
839time, looking into
840
841 http://www.perl.com/CPAN/ports/os2/ilyaz/
842
843may indicate the latest release which was publicly released by the
844maintainer. Note that the release may include some additional patches
845to apply to the current source of perl.
846
847Extract it like this
848
849 tar vzxf perl5.00409.tar.gz
850
851You may see a message about errors while extracting F<Configure>. This is
852because there is a conflict with a similarly-named file F<configure>.
853
a56dbb1c
PP
854Change to the directory of extraction.
855
856=head2 Application of the patches
857
10fb174d 858You need to apply the patches in F<./os2/diff.*> like this:
a56dbb1c 859
df3ef7a9 860 gnupatch -p0 < os2\diff.configure
a56dbb1c
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861
862You may also need to apply the patches supplied with the binary
863distribution of perl.
864
aa689395 865Note also that the F<db.lib> and F<db.a> from the EMX distribution
3998488b
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866are not suitable for multi-threaded compile (even single-threaded
867flavor of Perl uses multi-threaded C RTL, for
aa689395 868compatibility with XFree86-OS/2). Get a corrected one from
a56dbb1c
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869
870 ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
871
872=head2 Hand-editing
873
874You may look into the file F<./hints/os2.sh> and correct anything
875wrong you find there. I do not expect it is needed anywhere.
615d1a09 876
a56dbb1c 877=head2 Making
615d1a09 878
a56dbb1c 879 sh Configure -des -D prefix=f:/perllib
615d1a09 880
aa689395 881C<prefix> means: where to install the resulting perl library. Giving
a56dbb1c
PP
882correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
883see L<"PERLLIB_PREFIX">.
5243f9ae 884
a56dbb1c 885I<Ignore the message about missing C<ln>, and about C<-c> option to
3998488b
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886tr>. The latter is most probably already fixed, if you see it and can trace
887where the latter spurious warning comes from, please inform me.
615d1a09 888
a56dbb1c 889Now
5243f9ae 890
a56dbb1c 891 make
5243f9ae 892
a56dbb1c 893At some moment the built may die, reporting a I<version mismatch> or
3998488b
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894I<unable to run F<perl>>. This means that you do not have F<.> in
895your LIBPATH, so F<perl.exe> cannot find the needed F<perl67B2.dll> (treat
896these hex digits as line noise). After this is fixed the build
897should finish without a lot of fuss.
615d1a09 898
a56dbb1c
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899=head2 Testing
900
901Now run
902
903 make test
904
3998488b 905All tests should succeed (with some of them skipped).
a56dbb1c 906
ec40c0cd 907Some tests may generate extra messages similar to
a56dbb1c 908
ec40c0cd 909=over 4
a56dbb1c 910
ec40c0cd 911=item A lot of C<bad free>
a56dbb1c 912
3998488b
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913in database tests related to Berkeley DB. I<This should be fixed already.>
914If it persists, you may disable this warnings, see L<"PERL_BADFREE">.
72ea3524 915
ec40c0cd 916=item Process terminated by SIGTERM/SIGINT
72ea3524 917
ec40c0cd 918This is a standard message issued by OS/2 applications. *nix
3998488b 919applications die in silence. It is considered to be a feature. One can
ec40c0cd 920easily disable this by appropriate sighandlers.
a56dbb1c 921
ec40c0cd
IZ
922However the test engine bleeds these message to screen in unexpected
923moments. Two messages of this kind I<should> be present during
924testing.
a56dbb1c 925
ec40c0cd 926=back
a56dbb1c 927
ec40c0cd
IZ
928To get finer test reports, call
929
930 perl t/harness
931
932The report with F<io/pipe.t> failing may look like this:
a56dbb1c 933
ec40c0cd
IZ
934 Failed Test Status Wstat Total Fail Failed List of failed
935 ------------------------------------------------------------
936 io/pipe.t 12 1 8.33% 9
937 7 tests skipped, plus 56 subtests skipped.
938 Failed 1/195 test scripts, 99.49% okay. 1/6542 subtests failed, 99.98% okay.
939
940The reasons for most important skipped tests are:
941
942=over 8
a56dbb1c 943
ec40c0cd 944=item F<op/fs.t>
a56dbb1c 945
a7665c5e
GS
946=over 4
947
a56dbb1c
PP
948=item 18
949
ec40c0cd
IZ
950Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS
951provides only 2sec time granularity (for compatibility with FAT?).
a56dbb1c
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952
953=item 25
954
955Checks C<truncate()> on a filehandle just opened for write - I do not
956know why this should or should not work.
957
958=back
959
a56dbb1c
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960=item F<op/stat.t>
961
962Checks C<stat()>. Tests:
963
964=over 4
965
a56dbb1c
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966=item 4
967
ec40c0cd
IZ
968Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS
969provides only 2sec time granularity (for compatibility with FAT?).
a56dbb1c
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970
971=back
972
a56dbb1c 973=back
615d1a09 974
a56dbb1c 975=head2 Installing the built perl
615d1a09 976
491527d0
GS
977If you haven't yet moved perl.dll onto LIBPATH, do it now.
978
a56dbb1c 979Run
615d1a09 980
a56dbb1c 981 make install
615d1a09 982
a56dbb1c
PP
983It would put the generated files into needed locations. Manually put
984F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
aa689395 985PATH, F<perl.dll> to a location on your LIBPATH.
615d1a09 986
a56dbb1c 987Run
615d1a09 988
3998488b 989 make installcmd INSTALLCMDDIR=d:/ir/on/path
615d1a09 990
a56dbb1c 991to convert perl utilities to F<.cmd> files and put them on
aa689395 992PATH. You need to put F<.EXE>-utilities on path manually. They are
a56dbb1c
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993installed in C<$prefix/bin>, here C<$prefix> is what you gave to
994F<Configure>, see L<Making>.
995
996=head2 C<a.out>-style build
997
998Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
999
1000 make perl_
1001
1002test and install by
1003
1004 make aout_test
1005 make aout_install
1006
aa689395 1007Manually put F<perl_.exe> to a location on your PATH.
a56dbb1c 1008
a56dbb1c
PP
1009B<Note.> The build process for C<perl_> I<does not know> about all the
1010dependencies, so you should make sure that anything is up-to-date,
1011say, by doing
1012
3998488b 1013 make perl_dll
a56dbb1c
PP
1014
1015first.
1016
1017=head1 Build FAQ
1018
1019=head2 Some C</> became C<\> in pdksh.
1020
1021You have a very old pdksh. See L<Prerequisites>.
1022
1023=head2 C<'errno'> - unresolved external
1024
1025You do not have MT-safe F<db.lib>. See L<Prerequisites>.
1026
2c2e0e8c 1027=head2 Problems with tr or sed
a56dbb1c 1028
2c2e0e8c 1029reported with very old version of tr and sed.
a56dbb1c
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1030
1031=head2 Some problem (forget which ;-)
1032
aa689395 1033You have an older version of F<perl.dll> on your LIBPATH, which
a56dbb1c
PP
1034broke the build of extensions.
1035
1036=head2 Library ... not found
1037
1038You did not run C<omflibs>. See L<Prerequisites>.
1039
1040=head2 Segfault in make
1041
aa689395 1042You use an old version of GNU make. See L<Prerequisites>.
a56dbb1c 1043
884335e8
YST
1044=head2 op/sprintf test failure
1045
1046This can result from a bug in emx sprintf which was fixed in 0.9d fix 03.
1047
a56dbb1c
PP
1048=head1 Specific (mis)features of OS/2 port
1049
1050=head2 C<setpriority>, C<getpriority>
1051
1052Note that these functions are compatible with *nix, not with the older
1053ports of '94 - 95. The priorities are absolute, go from 32 to -95,
72ea3524 1054lower is quicker. 0 is the default priority.
a56dbb1c 1055
3998488b
JH
1056B<WARNING>. Calling C<getpriority> on a non-existing process can lock the
1057system before Warp3 fixpak22.
1058
a56dbb1c
PP
1059=head2 C<system()>
1060
1061Multi-argument form of C<system()> allows an additional numeric
1062argument. The meaning of this argument is described in
1063L<OS2::Process>.
1064
3998488b
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1065When finding a program to run, Perl first asks the OS to look for executables
1066on C<PATH>. If not found, it looks for a script with possible extensions
1067added in this order: no extension, F<.cmd>, F<.btm>,
1068F<.bat>, F<.pl>. If found, Perl checks the start of the file for magic
1069strings C<"#!"> and C<"extproc ">. If found, Perl uses the rest of the
1070first line as the beginning of the command line to run this script. The
1071only mangling done to the first line is extraction of arguments (currently
1072up to 3), and ignoring of the path-part of the "interpreter" name if it can't
1073be found using the full path.
1074
1075E.g., C<system 'foo', 'bar', 'baz'> may lead Perl to finding
1076F<C:/emx/bin/foo.cmd> with the first line being
1077
1078 extproc /bin/bash -x -c
1079
1080If F</bin/bash> is not found, and appending of executable extensions to
1081F</bin/bash> does not help either, then Perl looks for an executable F<bash> on
1082C<PATH>. If found in F<C:/emx.add/bin/bash.exe>, then the above system() is
1083translated to
1084
1085 system qw(C:/emx.add/bin/bash.exe -x -c C:/emx/bin/foo.cmd bar baz)
1086
1087One additional translation is performed: instead of F</bin/sh> Perl uses
1088the hardwired-or-customized shell (see C<L<"PERL_SH_DIR">>).
1089
1090The above search for "interpreter" is recursive: if F<bash> executable is not
1091found, but F<bash.btm> is found, Perl will investigate its first line etc.
1092The only hardwired limit on the recursion depth is implicit: there is a limit
10934 on the number of additional arguments inserted before the actual arguments
1094given to system(). In particular, if no additional arguments are specified
1095on the "magic" first lines, then the limit on the depth is 4.
1096
1097If Perl finds that the found executable is of different type than the
1098current session, it will start the new process in a separate session of
1099necessary type. Call via C<OS2::Process> to disable this magic.
1100
aa689395
PP
1101=head2 C<extproc> on the first line
1102
3998488b 1103If the first chars of a Perl script are C<"extproc ">, this line is treated
aa689395 1104as C<#!>-line, thus all the switches on this line are processed (twice
3998488b 1105if script was started via cmd.exe). See L<perlrun/DESCRIPTION>.
aa689395 1106
a56dbb1c 1107=head2 Additional modules:
615d1a09 1108
3998488b 1109L<OS2::Process>, L<OS2::DLL>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. These
2c2e0e8c 1110modules provide access to additional numeric argument for C<system>
3998488b
JH
1111and to the information about the running process,
1112to DLLs having functions with REXX signature and to the REXX runtime, to
a56dbb1c 1113OS/2 databases in the F<.INI> format, and to Extended Attributes.
615d1a09 1114
72ea3524 1115Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
3998488b 1116C<OS2::FTP>, are included into C<ILYAZ> directory, mirrored on CPAN.
615d1a09 1117
a56dbb1c 1118=head2 Prebuilt methods:
615d1a09 1119
a56dbb1c 1120=over 4
615d1a09 1121
a56dbb1c 1122=item C<File::Copy::syscopy>
615d1a09 1123
d7678ab8 1124used by C<File::Copy::copy>, see L<File::Copy>.
615d1a09 1125
a56dbb1c 1126=item C<DynaLoader::mod2fname>
615d1a09 1127
72ea3524 1128used by C<DynaLoader> for DLL name mangling.
615d1a09 1129
a56dbb1c 1130=item C<Cwd::current_drive()>
615d1a09 1131
a56dbb1c 1132Self explanatory.
615d1a09 1133
a56dbb1c 1134=item C<Cwd::sys_chdir(name)>
615d1a09 1135
a56dbb1c 1136leaves drive as it is.
615d1a09 1137
a56dbb1c 1138=item C<Cwd::change_drive(name)>
615d1a09 1139
3998488b 1140chanes the "current" drive.
615d1a09 1141
a56dbb1c 1142=item C<Cwd::sys_is_absolute(name)>
615d1a09 1143
a56dbb1c 1144means has drive letter and is_rooted.
615d1a09 1145
a56dbb1c 1146=item C<Cwd::sys_is_rooted(name)>
615d1a09 1147
a56dbb1c 1148means has leading C<[/\\]> (maybe after a drive-letter:).
615d1a09 1149
a56dbb1c 1150=item C<Cwd::sys_is_relative(name)>
615d1a09 1151
a56dbb1c 1152means changes with current dir.
615d1a09 1153
a56dbb1c 1154=item C<Cwd::sys_cwd(name)>
615d1a09 1155
aa689395 1156Interface to cwd from EMX. Used by C<Cwd::cwd>.
615d1a09 1157
a56dbb1c 1158=item C<Cwd::sys_abspath(name, dir)>
615d1a09 1159
a56dbb1c
PP
1160Really really odious function to implement. Returns absolute name of
1161file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the
1162current dir.
615d1a09 1163
6d0f518e 1164=item C<Cwd::extLibpath([type])>
615d1a09 1165
a56dbb1c
PP
1166Get current value of extended library search path. If C<type> is
1167present and I<true>, works with END_LIBPATH, otherwise with
1168C<BEGIN_LIBPATH>.
615d1a09 1169
a56dbb1c 1170=item C<Cwd::extLibpath_set( path [, type ] )>
615d1a09 1171
a56dbb1c
PP
1172Set current value of extended library search path. If C<type> is
1173present and I<true>, works with END_LIBPATH, otherwise with
1174C<BEGIN_LIBPATH>.
615d1a09 1175
3998488b
JH
1176=item C<OS2::Error(do_harderror,do_exception)>
1177
1178Returns C<undef> if it was not called yet, otherwise bit 1 is
1179set if on the previous call do_harderror was enabled, bit
11802 is set if if on previous call do_exception was enabled.
1181
1182This function enables/disables error popups associated with
1183hardware errors (Disk not ready etc.) and software exceptions.
1184
1185I know of no way to find out the state of popups I<before> the first call
1186to this function.
1187
1188=item C<OS2::Errors2Drive(drive)>
1189
1190Returns C<undef> if it was not called yet, otherwise return false if errors
1191were not requested to be written to a hard drive, or the drive letter if
1192this was requested.
1193
1194This function may redirect error popups associated with hardware errors
1195(Disk not ready etc.) and software exceptions to the file POPUPLOG.OS2 at
1196the root directory of the specified drive. Overrides OS2::Error() specified
1197by individual programs. Given argument undef will disable redirection.
1198
1199Has global effect, persists after the application exits.
1200
1201I know of no way to find out the state of redirection of popups to the disk
1202I<before> the first call to this function.
1203
1204=item OS2::SysInfo()
1205
1206Returns a hash with system information. The keys of the hash are
1207
1208 MAX_PATH_LENGTH, MAX_TEXT_SESSIONS, MAX_PM_SESSIONS,
1209 MAX_VDM_SESSIONS, BOOT_DRIVE, DYN_PRI_VARIATION,
1210 MAX_WAIT, MIN_SLICE, MAX_SLICE, PAGE_SIZE,
1211 VERSION_MAJOR, VERSION_MINOR, VERSION_REVISION,
1212 MS_COUNT, TIME_LOW, TIME_HIGH, TOTPHYSMEM, TOTRESMEM,
1213 TOTAVAILMEM, MAXPRMEM, MAXSHMEM, TIMER_INTERVAL,
1214 MAX_COMP_LENGTH, FOREGROUND_FS_SESSION,
1215 FOREGROUND_PROCESS
1216
1217=item OS2::BootDrive()
1218
1219Returns a letter without colon.
1220
1221=item C<OS2::MorphPM(serve)>, C<OS2::UnMorphPM(serve)>
1222
1223Transforms the current application into a PM application and back.
1224The argument true means that a real message loop is going to be served.
1225OS2::MorphPM() returns the PM message queue handle as an integer.
1226
1227See L<"Centralized management of resources"> for additional details.
1228
1229=item C<OS2::Serve_Messages(force)>
1230
1231Fake on-demand retrieval of outstanding PM messages. If C<force> is false,
1232will not dispatch messages if a real message loop is known to
1233be present. Returns number of messages retrieved.
1234
1235Dies with "QUITing..." if WM_QUIT message is obtained.
1236
1237=item C<OS2::Process_Messages(force [, cnt])>
1238
1239Retrieval of PM messages until window creation/destruction.
1240If C<force> is false, will not dispatch messages if a real message loop
1241is known to be present.
1242
1243Returns change in number of windows. If C<cnt> is given,
1244it is incremented by the number of messages retrieved.
1245
1246Dies with "QUITing..." if WM_QUIT message is obtained.
1247
1248=item C<OS2::_control87(new,mask)>
1249
1250the same as L<_control87(3)> of EMX. Takes integers as arguments, returns
1251the previous coprocessor control word as an integer. Only bits in C<new> which
1252are present in C<mask> are changed in the control word.
1253
1254=item OS2::get_control87()
1255
1256gets the coprocessor control word as an integer.
1257
1258=item C<OS2::set_control87_em(new=MCW_EM,mask=MCW_EM)>
1259
1260The variant of OS2::_control87() with default values good for
1261handling exception mask: if no C<mask>, uses exception mask part of C<new>
1262only. If no C<new>, disables all the floating point exceptions.
1263
1264See L<"Misfeatures"> for details.
1265
a56dbb1c 1266=back
615d1a09 1267
a56dbb1c
PP
1268(Note that some of these may be moved to different libraries -
1269eventually).
615d1a09 1270
615d1a09 1271
3998488b
JH
1272=head2 Prebuilt variables:
1273
1274=over 4
1275
1276=item $OS2::emx_rev
1277
1278same as _emx_rev of EMX, a string similar to C<0.9c>.
1279
1280=item $OS2::emx_env
1281
1282same as _emx_env of EMX, a number similar to 0x8001.
1283
1284=item $OS2::os_ver
1285
1286a number C<OS_MAJOR + 0.001 * OS_MINOR>.
1287
1288=back
1289
a56dbb1c 1290=head2 Misfeatures
615d1a09 1291
a56dbb1c 1292=over 4
615d1a09 1293
13a2d996 1294=item *
615d1a09 1295
367f3c24
IZ
1296Since L<flock(3)> is present in EMX, but is not functional, it is
1297emulated by perl. To disable the emulations, set environment variable
1298C<USE_PERL_FLOCK=0>.
1299
13a2d996 1300=item *
367f3c24
IZ
1301
1302Here is the list of things which may be "broken" on
55497cff
PP
1303EMX (from EMX docs):
1304
13a2d996 1305=over 4
d7678ab8
CS
1306
1307=item *
1308
1309The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not
1310implemented.
1311
1312=item *
1313
1314L<sock_init(3)> is not required and not implemented.
1315
1316=item *
1317
367f3c24 1318L<flock(3)> is not yet implemented (dummy function). (Perl has a workaround.)
d7678ab8
CS
1319
1320=item *
1321
1322L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented.
1323
1324=item *
1325
1326L<waitpid(3)>:
1327
55497cff
PP
1328 WUNTRACED
1329 Not implemented.
1330 waitpid() is not implemented for negative values of PID.
1331
d7678ab8
CS
1332=back
1333
55497cff 1334Note that C<kill -9> does not work with the current version of EMX.
615d1a09 1335
13a2d996 1336=item *
615d1a09 1337
72ea3524 1338Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
a56dbb1c 1339of F<sh.exe> plague perl as well.
615d1a09 1340
a56dbb1c 1341In particular, uppercase letters do not work in C<[...]>-patterns with
aa689395 1342the current pdksh.
615d1a09 1343
3998488b
JH
1344=item *
1345
1346Unix-domain sockets on OS/2 live in a pseudo-file-system C</sockets/...>.
1347To avoid a failure to create a socket with a name of a different form,
1348C<"/socket/"> is prepended to the socket name (unless it starts with this
1349already).
1350
1351This may lead to problems later in case the socket is accessed via the
1352"usual" file-system calls using the "initial" name.
1353
1354=item *
1355
1356Apparently, IBM used a compiler (for some period of time around '95?) which
1357changes FP mask right and left. This is not I<that> bad for IBM's
1358programs, but the same compiler was used for DLLs which are used with
1359general-purpose applications. When these DLLs are used, the state of
1360floating-point flags in the application is not predictable.
1361
1362What is much worse, some DLLs change the floating point flags when in
1363_DLLInitTerm() (e.g., F<TCP32IP>). This means that even if you do not I<call>
1364any function in the DLL, just the act of loading this DLL will reset your
1365flags. What is worse, the same compiler was used to compile some HOOK DLLs.
1366Given that HOOK dlls are executed in the context of I<all> the applications
1367in the system, this means a complete unpredictablity of floating point
1368flags on systems using such HOOK DLLs. E.g., F<GAMESRVR.DLL> of B<DIVE>
1369origin changes the floating point flags on each write to the TTY of a VIO
1370(windowed text-mode) applications.
1371
1372Some other (not completely debugged) situations when FP flags change include
1373some video drivers (?), and some operations related to creation of the windows.
1374People who code B<OpenGL> may have more experience on this.
1375
1376Perl is generally used in the situation when all the floating-point
1377exceptions are ignored, as is the default under EMX. If they are not ignored,
1378some benign Perl programs would get a C<SIGFPE> and would die a horrible death.
1379
1380To circumvent this, Perl uses two hacks. They help against I<one> type of
1381damage only: FP flags changed when loading a DLL.
1382
1383One of the hacks is to disable floating point exceptions on startup (as
1384is the default with EMX). This helps only with compile-time-linked DLLs
1385changing the flags before main() had a chance to be called.
1386
1387The other hack is to restore FP flags after a call to dlopen(). This helps
1388against similar damage done by DLLs _DLLInitTerm() at runtime. Currently
1389no way to switch these hacks off is provided.
1390
a56dbb1c 1391=back
615d1a09 1392
55497cff
PP
1393=head2 Modifications
1394
1395Perl modifies some standard C library calls in the following ways:
1396
1397=over 9
1398
1399=item C<popen>
1400
72ea3524 1401C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">.
55497cff
PP
1402
1403=item C<tmpnam>
1404
1405is created using C<TMP> or C<TEMP> environment variable, via
1406C<tempnam>.
1407
1408=item C<tmpfile>
1409
72ea3524 1410If the current directory is not writable, file is created using modified
55497cff
PP
1411C<tmpnam>, so there may be a race condition.
1412
1413=item C<ctermid>
1414
1415a dummy implementation.
1416
1417=item C<stat>
1418
1419C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
1420
3998488b
JH
1421=item C<mkdir>, C<rmdir>
1422
1423these EMX functions do not work if the path contains a trailing C</>.
1424Perl contains a workaround for this.
1425
367f3c24
IZ
1426=item C<flock>
1427
1428Since L<flock(3)> is present in EMX, but is not functional, it is
1429emulated by perl. To disable the emulations, set environment variable
1430C<USE_PERL_FLOCK=0>.
1431
55497cff
PP
1432=back
1433
3998488b
JH
1434=head2 Identifying DLLs
1435
1436All the DLLs built with the current versions of Perl have ID strings
1437identifying the name of the extension, its version, and the version
1438of Perl required for this DLL. Run C<bldlevel DLL-name> to find this
1439info.
1440
1441=head2 Centralized management of resources
1442
1443Since to call certain OS/2 API one needs to have a correctly initialized
1444C<Win> subsystem, OS/2-specific extensions may require getting C<HAB>s and
1445C<HMQ>s. If an extension would do it on its own, another extension could
1446fail to initialize.
1447
1448Perl provides a centralized management of these resources:
1449
1450=over
1451
1452=item C<HAB>
1453
1454To get the HAB, the extension should call C<hab = perl_hab_GET()> in C. After
1455this call is performed, C<hab> may be accessed as C<Perl_hab>. There is
1456no need to release the HAB after it is used.
1457
1458If by some reasons F<perl.h> cannot be included, use
1459
1460 extern int Perl_hab_GET(void);
1461
1462instead.
1463
1464=item C<HMQ>
1465
1466There are two cases:
1467
1468=over
1469
1470=item *
1471
1472the extension needs an C<HMQ> only because some API will not work otherwise.
1473Use C<serve = 0> below.
1474
1475=item *
1476
1477the extension needs an C<HMQ> since it wants to engage in a PM event loop.
1478Use C<serve = 1> below.
1479
1480=back
1481
1482To get an C<HMQ>, the extension should call C<hmq = perl_hmq_GET(serve)> in C.
1483After this call is performed, C<hmq> may be accessed as C<Perl_hmq>.
1484
1485To signal to Perl that HMQ is not needed any more, call
1486C<perl_hmq_UNSET(serve)>. Perl process will automatically morph/unmorph itself
1487into/from a PM process if HMQ is needed/not-needed. Perl will automatically
1488enable/disable C<WM_QUIT> message during shutdown if the message queue is
1489served/not-served.
1490
1491B<NOTE>. If during a shutdown there is a message queue which did not disable
1492WM_QUIT, and which did not process the received WM_QUIT message, the
1493shutdown will be automatically cancelled. Do not call C<perl_hmq_GET(1)>
1494unless you are going to process messages on an orderly basis.
1495
1496=back
1497
a56dbb1c 1498=head1 Perl flavors
615d1a09 1499
72ea3524 1500Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
aa689395 1501same basket (though EMX environment tries hard to overcome this
a56dbb1c
PP
1502limitations, so the situation may somehow improve). There are 4
1503executables for Perl provided by the distribution:
615d1a09 1504
a56dbb1c 1505=head2 F<perl.exe>
615d1a09 1506
a56dbb1c
PP
1507The main workhorse. This is a chimera executable: it is compiled as an
1508C<a.out>-style executable, but is linked with C<omf>-style dynamic
aa689395
PP
1509library F<perl.dll>, and with dynamic CRT DLL. This executable is a
1510VIO application.
a56dbb1c 1511
3998488b 1512It can load perl dynamic extensions, and it can fork().
a56dbb1c
PP
1513
1514B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
1515
1516=head2 F<perl_.exe>
1517
3998488b
JH
1518This is a statically linked C<a.out>-style executable. It cannot
1519load dynamic Perl extensions. The executable supplied in binary
1520distributions has a lot of extensions prebuilt, thus the above restriction is
1521important only if you use custom-built extensions. This executable is a VIO
a56dbb1c
PP
1522application.
1523
3998488b 1524I<This is the only executable with does not require OS/2.> The
a56dbb1c 1525friends locked into C<M$> world would appreciate the fact that this
72ea3524 1526executable runs under DOS, Win0.3*, Win0.95 and WinNT with an
a56dbb1c
PP
1527appropriate extender. See L<"Other OSes">.
1528
1529=head2 F<perl__.exe>
1530
aa689395 1531This is the same executable as F<perl___.exe>, but it is a PM
a56dbb1c
PP
1532application.
1533
3998488b
JH
1534B<Note.> Usually (unless explicitly redirected during the startup)
1535STDIN, STDERR, and STDOUT of a PM
1536application are redirected to F<nul>. However, it is possible to I<see>
a56dbb1c 1537them if you start C<perl__.exe> from a PM program which emulates a
aa689395 1538console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
a56dbb1c 1539possible> to use Perl debugger (see L<perldebug>) to debug your PM
3998488b
JH
1540application (but beware of the message loop lockups - this will not
1541work if you have a message queue to serve, unless you hook the serving
1542into the getc() function of the debugger).
a56dbb1c 1543
3998488b
JH
1544Another way to see the output of a PM program is to run it as
1545
1546 pm_prog args 2>&1 | cat -
1547
1548with a shell I<different> from F<cmd.exe>, so that it does not create
1549a link between a VIO session and the session of C<pm_porg>. (Such a link
1550closes the VIO window.) E.g., this works with F<sh.exe> - or with Perl!
1551
1552 open P, 'pm_prog args 2>&1 |' or die;
1553 print while <P>;
1554
1555The flavor F<perl__.exe> is required if you want to start your program without
1556a VIO window present, but not C<detach>ed (run C<help detach> for more info).
1557Very useful for extensions which use PM, like C<Perl/Tk> or C<OpenGL>.
a56dbb1c
PP
1558
1559=head2 F<perl___.exe>
1560
1561This is an C<omf>-style executable which is dynamically linked to
aa689395 1562F<perl.dll> and CRT DLL. I know no advantages of this executable
a56dbb1c
PP
1563over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
1564that the build process is not so convoluted as with C<perl.exe>.
1565
aa689395 1566It is a VIO application.
a56dbb1c
PP
1567
1568=head2 Why strange names?
1569
1570Since Perl processes the C<#!>-line (cf.
1571L<perlrun/DESCRIPTION>, L<perlrun/Switches>,
1572L<perldiag/"Not a perl script">,
1573L<perldiag/"No Perl script found in input">), it should know when a
1574program I<is a Perl>. There is some naming convention which allows
1575Perl to distinguish correct lines from wrong ones. The above names are
72ea3524 1576almost the only names allowed by this convention which do not contain
a56dbb1c
PP
1577digits (which have absolutely different semantics).
1578
1579=head2 Why dynamic linking?
1580
1581Well, having several executables dynamically linked to the same huge
1582library has its advantages, but this would not substantiate the
3998488b
JH
1583additional work to make it compile. The reason is the complicated-to-developers
1584but very quick and convenient-to-users "hard" dynamic linking used by OS/2.
1585
1586There are two distinctive features of the dyna-linking model of OS/2:
1587all the references to external functions are resolved at the compile time;
1588there is no runtime fixup of the DLLs after they are loaded into memory.
1589The first feature is an enormous advantage over other models: it avoids
1590conflicts when several DLLs used by an application export entries with
1591the same name. In such cases "other" models of dyna-linking just choose
1592between these two entry points using some random criterion - with predictable
1593disasters as results. But it is the second feature which requires the build
1594of F<perl.dll>.
a56dbb1c 1595
72ea3524 1596The address tables of DLLs are patched only once, when they are
3998488b
JH
1597loaded. The addresses of the entry points into DLLs are guaranteed to be
1598the same for all the programs which use the same DLL. This removes the
1599runtime fixup - once DLL is loaded, its code is read-only.
a56dbb1c 1600
3998488b
JH
1601While this allows some (significant?) performance advantages, this makes life
1602much harder for developers, since the above scheme makes it impossible
1603for a DLL to be "linked" to a symbol in the F<.EXE> file. Indeed, this
1604would need a DLL to have different relocations tables for the
1605(different) executables which use this DLL.
1606
1607However, a dynamically loaded Perl extension is forced to use some symbols
1608from the perl
1609executable, e.g., to know how to find the arguments to the functions:
1610the arguments live on the perl
1611internal evaluation stack. The solution is to put the main code of
1612the interpreter into a DLL, and make the F<.EXE> file which just loads
1613this DLL into memory and supplies command-arguments. The extension DLL
1614cannot link to symbols in F<.EXE>, but it has no problem linking
1615to symbols in the F<.DLL>.
a56dbb1c 1616
72ea3524 1617This I<greatly> increases the load time for the application (as well as
3998488b
JH
1618complexity of the compilation). Since interpreter is in a DLL,
1619the C RTL is basically forced to reside in a DLL as well (otherwise
1620extensions would not be able to use CRT). There are some advantages if
1621you use different flavors of perl, such as running F<perl.exe> and
1622F<perl__.exe> simultaneously: they share the memory of F<perl.dll>.
1623
1624B<NOTE>. There is one additional effect which makes DLLs more wasteful:
1625DLLs are loaded in the shared memory region, which is a scarse resource
1626given the 512M barrier of the "standard" OS/2 virtual memory. The code of
1627F<.EXE> files is also shared by all the processes which use the particular
1628F<.EXE>, but they are "shared in the private address space of the process";
1629this is possible because the address at which different sections
1630of the F<.EXE> file are loaded is decided at compile-time, thus all the
1631processes have these sections loaded at same addresses, and no fixup
1632of internal links inside the F<.EXE> is needed.
1633
1634Since DLLs may be loaded at run time, to have the same mechanism for for DLLs
1635one needs to have the address range of I<any of the loaded> DLLs in the
1636system to be available I<in all the processes> which did not load a particular
1637DLL yet. This is why the DLLs are mapped to the shared memory region.
a56dbb1c
PP
1638
1639=head2 Why chimera build?
1640
aa689395 1641Current EMX environment does not allow DLLs compiled using Unixish
3998488b
JH
1642C<a.out> format to export symbols for data (or at least some types of
1643data). This forces C<omf>-style compile of F<perl.dll>.
a56dbb1c 1644
aa689395 1645Current EMX environment does not allow F<.EXE> files compiled in
a56dbb1c
PP
1646C<omf> format to fork(). fork() is needed for exactly three Perl
1647operations:
1648
1649=over 4
1650
3998488b 1651=item *
a56dbb1c 1652
3998488b 1653explicit fork() in the script,
a56dbb1c 1654
3998488b 1655=item *
a56dbb1c 1656
3998488b
JH
1657C<open FH, "|-">
1658
1659=item *
a56dbb1c 1660
3998488b 1661C<open FH, "-|">, in other words, opening pipes to itself.
a56dbb1c
PP
1662
1663=back
1664
3998488b
JH
1665While these operations are not questions of life and death, they are
1666needed for a lot of
1667useful scripts. This forces C<a.out>-style compile of
a56dbb1c
PP
1668F<perl.exe>.
1669
1670
1671=head1 ENVIRONMENT
1672
aa689395
PP
1673Here we list environment variables with are either OS/2- and DOS- and
1674Win*-specific, or are more important under OS/2 than under other OSes.
a56dbb1c
PP
1675
1676=head2 C<PERLLIB_PREFIX>
1677
aa689395 1678Specific for EMX port. Should have the form
a56dbb1c
PP
1679
1680 path1;path2
1681
1682or
1683
1684 path1 path2
1685
1686If the beginning of some prebuilt path matches F<path1>, it is
1687substituted with F<path2>.
1688
1689Should be used if the perl library is moved from the default
1690location in preference to C<PERL(5)LIB>, since this would not leave wrong
3998488b 1691entries in @INC. For example, if the compiled version of perl looks for @INC
eb447b86
IZ
1692in F<f:/perllib/lib>, and you want to install the library in
1693F<h:/opt/gnu>, do
1694
1695 set PERLLIB_PREFIX=f:/perllib/lib;h:/opt/gnu
a56dbb1c 1696
3998488b
JH
1697This will cause Perl with the prebuilt @INC of
1698
1699 f:/perllib/lib/5.00553/os2
1700 f:/perllib/lib/5.00553
1701 f:/perllib/lib/site_perl/5.00553/os2
1702 f:/perllib/lib/site_perl/5.00553
1703 .
1704
1705to use the following @INC:
1706
1707 h:/opt/gnu/5.00553/os2
1708 h:/opt/gnu/5.00553
1709 h:/opt/gnu/site_perl/5.00553/os2
1710 h:/opt/gnu/site_perl/5.00553
1711 .
1712
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1713=head2 C<PERL_BADLANG>
1714
3998488b 1715If 0, perl ignores setlocale() failing. May be useful with some
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1716strange I<locale>s.
1717
1718=head2 C<PERL_BADFREE>
1719
3998488b
JH
1720If 0, perl would not warn of in case of unwarranted free(). With older
1721perls this might be
1722useful in conjunction with the module DB_File, which was buggy when
1723dynamically linked and OMF-built.
1724
1725Should not be set with newer Perls, since this may hide some I<real> problems.
a56dbb1c
PP
1726
1727=head2 C<PERL_SH_DIR>
1728
aa689395 1729Specific for EMX port. Gives the directory part of the location for
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1730F<sh.exe>.
1731
367f3c24
IZ
1732=head2 C<USE_PERL_FLOCK>
1733
1734Specific for EMX port. Since L<flock(3)> is present in EMX, but is not
1735functional, it is emulated by perl. To disable the emulations, set
1736environment variable C<USE_PERL_FLOCK=0>.
1737
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PP
1738=head2 C<TMP> or C<TEMP>
1739
3998488b 1740Specific for EMX port. Used as storage place for temporary files.
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PP
1741
1742=head1 Evolution
1743
1744Here we list major changes which could make you by surprise.
1745
1746=head2 Priorities
1747
1748C<setpriority> and C<getpriority> are not compatible with earlier
1749ports by Andreas Kaiser. See C<"setpriority, getpriority">.
1750
72ea3524 1751=head2 DLL name mangling
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1752
1753With the release 5.003_01 the dynamically loadable libraries
3998488b
JH
1754should be rebuilt when a different version of Perl is compiled. In particular,
1755DLLs (including F<perl.dll>) are now created with the names
a56dbb1c
PP
1756which contain a checksum, thus allowing workaround for OS/2 scheme of
1757caching DLLs.
1758
3998488b
JH
1759It may be possible to code a simple workaround which would
1760
1761=over
1762
1763=item *
1764
1765find the old DLLs looking through the old @INC;
1766
1767=item *
1768
1769mangle the names according to the scheme of new perl and copy the DLLs to
1770these names;
1771
1772=item *
1773
1774edit the internal C<LX> tables of DLL to reflect the change of the name
1775(probably not needed for Perl extension DLLs, since the internally coded names
1776are not used for "specific" DLLs, they used only for "global" DLLs).
1777
1778=item *
1779
1780edit the internal C<IMPORT> tables and change the name of the "old"
1781F<perl????.dll> to the "new" F<perl????.dll>.
1782
1783=back
1784
a56dbb1c
PP
1785=head2 Threading
1786
3998488b
JH
1787As of release 5.003_01 perl is linked to multithreaded C RTL
1788DLL. If perl itself is not compiled multithread-enabled, so will not be perl's
a56dbb1c
PP
1789malloc(). However, extensions may use multiple thread on their own
1790risk.
1791
3998488b
JH
1792This was needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box, and
1793link with DLLs for other useful libraries, which typically are compiled
1794with C<-Zmt -Zcrtdll>.
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1795
1796=head2 Calls to external programs
1797
1798Due to a popular demand the perl external program calling has been
72ea3524 1799changed wrt Andreas Kaiser's port. I<If> perl needs to call an
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1800external program I<via shell>, the F<f:/bin/sh.exe> will be called, or
1801whatever is the override, see L<"PERL_SH_DIR">.
1802
1803Thus means that you need to get some copy of a F<sh.exe> as well (I
3998488b 1804use one from pdksh). The path F<F:/bin> above is set up automatically during
a56dbb1c
PP
1805the build to a correct value on the builder machine, but is
1806overridable at runtime,
1807
1808B<Reasons:> a consensus on C<perl5-porters> was that perl should use
1809one non-overridable shell per platform. The obvious choices for OS/2
1810are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
3998488b 1811with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. This assures almost
aa689395
PP
1812100% compatibility with the scripts coming from *nix. As an added benefit
1813this works as well under DOS if you use DOS-enabled port of pdksh
1814(see L<"Prerequisites">).
a56dbb1c 1815
aa689395 1816B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
a56dbb1c 1817via fork()/exec(), and there is I<no> functioning exec() on
3998488b 1818OS/2. exec() is emulated by EMX by an asynchronous call while the caller
72ea3524 1819waits for child completion (to pretend that the C<pid> did not change). This
a56dbb1c
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1820means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(),
1821which may lead to some resources taken from the system (even if we do
1822not count extra work needed for fork()ing).
1823
72ea3524
IZ
1824Note that this a lesser issue now when we do not spawn F<sh.exe>
1825unless needed (metachars found).
1826
1827One can always start F<cmd.exe> explicitly via
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PP
1828
1829 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ...
1830
72ea3524 1831If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your
a56dbb1c
PP
1832scripts, the long-term solution proposed on p5-p is to have a directive
1833
1834 use OS2::Cmd;
1835
1836which will override system(), exec(), C<``>, and
1837C<open(,'...|')>. With current perl you may override only system(),
1838readpipe() - the explicit version of C<``>, and maybe exec(). The code
1839will substitute the one-argument call to system() by
1840C<CORE::system('cmd.exe', '/c', shift)>.
1841
1842If you have some working code for C<OS2::Cmd>, please send it to me,
1843I will include it into distribution. I have no need for such a module, so
1844cannot test it.
1845
2c2e0e8c 1846For the details of the current situation with calling external programs,
3998488b
JH
1847see L<Starting OS/2 (and DOS) programs under Perl>. Set us mention a couple
1848of features:
2c2e0e8c 1849
13a2d996 1850=over 4
2c2e0e8c 1851
13a2d996 1852=item *
2c2e0e8c 1853
3998488b
JH
1854External scripts may be called by their basename. Perl will try the same
1855extensions as when processing B<-S> command-line switch.
1856
1857=item *
1858
1859External scripts starting with C<#!> or C<extproc > will be executed directly,
1860without calling the shell, by calling the program specified on the rest of
1861the first line.
2c2e0e8c
IZ
1862
1863=back
1864
df3ef7a9
IZ
1865=head2 Memory allocation
1866
1867Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound
ec40c0cd 1868for speed, but perl is not, since its malloc is lightning-fast.
4375e838
GS
1869Perl-memory-usage-tuned benchmarks show that Perl's malloc is 5 times quicker
1870than EMX one. I do not have convincing data about memory footprint, but
3998488b 1871a (pretty random) benchmark showed that Perl's one is 5% better.
df3ef7a9
IZ
1872
1873Combination of perl's malloc() and rigid DLL name resolution creates
1874a special problem with library functions which expect their return value to
1875be free()d by system's free(). To facilitate extensions which need to call
1876such functions, system memory-allocation functions are still available with
1877the prefix C<emx_> added. (Currently only DLL perl has this, it should
1878propagate to F<perl_.exe> shortly.)
1879
ec40c0cd
IZ
1880=head2 Threads
1881
1882One can build perl with thread support enabled by providing C<-D usethreads>
1883option to F<Configure>. Currently OS/2 support of threads is very
1884preliminary.
1885
1886Most notable problems:
1887
13a2d996 1888=over 4
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IZ
1889
1890=item C<COND_WAIT>
1891
1892may have a race condition. Needs a reimplementation (in terms of chaining
3998488b 1893waiting threads, with the linked list stored in per-thread structure?).
ec40c0cd
IZ
1894
1895=item F<os2.c>
1896
1897has a couple of static variables used in OS/2-specific functions. (Need to be
1898moved to per-thread structure, or serialized?)
1899
1900=back
1901
1902Note that these problems should not discourage experimenting, since they
1903have a low probability of affecting small programs.
1904
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PP
1905=cut
1906
1907OS/2 extensions
1908~~~~~~~~~~~~~~~
72ea3524 1909I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP,
a56dbb1c
PP
1910into my ftp directory, mirrored on CPAN. I made
1911some minor changes needed to compile them by standard tools. I cannot
1912test UPM and FTP, so I will appreciate your feedback. Other extensions
1913there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
1914files - and maybe some other extensions at the time you read it.
1915
1916Note that OS2 perl defines 2 pseudo-extension functions
aa689395
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1917OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
1918L<Prebuilt methods>).
a56dbb1c
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1919
1920The -R switch of older perl is deprecated. If you need to call a REXX code
1921which needs access to variables, include the call into a REXX compartment
1922created by
1923 REXX_call {...block...};
1924
1925Two new functions are supported by REXX code,
1926 REXX_eval 'string';
1927 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference;
1928
1929If you have some other extensions you want to share, send the code to
1930me. At least two are available: tied access to EA's, and tied access
1931to system databases.
615d1a09 1932
a56dbb1c 1933=head1 AUTHOR
615d1a09 1934
a56dbb1c 1935Ilya Zakharevich, ilya@math.ohio-state.edu
615d1a09 1936
a56dbb1c 1937=head1 SEE ALSO
615d1a09 1938
a56dbb1c 1939perl(1).
615d1a09 1940
a56dbb1c 1941=cut
615d1a09 1942