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1 If you read this file _as_is_, just ignore the funny characters you 2 see. It is written in the POD format (see perlpod manpage) which is 3 specially designed to be readable as is. 4 5 =head1 NAME 6 7 perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT. 8 9 =head1 SYNOPSIS 10 11 One can read this document in the following formats: 12 13 man perlos2 14 view perl perlos2 15 explorer perlos2.html 16 info perlos2 17 18 to list some (not all may be available simultaneously), or it may 19 be read I<as is>: either as F<README.os2>, or F<pod/perlos2.pod>. 20 21 To read the F<.INF> version of documentation (B<very> recommended) 22 outside of OS/2, one needs an IBM's reader (may be available on IBM 23 ftp sites (?) (URL anyone?)) or shipped with PC DOS 7.0 and IBM's 24 Visual Age C++ 3.5. 25 26 A 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 30 in F<?:\JUST_ADD\view.exe>. This gives one an access to EMX's 31 F<.INF> docs as well (text form is available in F</emx/doc> in 32 EMX's distribution). There is also a different viewer named xview. 33 34 Note that if you have F<lynx.exe> or F<netscape.exe> installed, you can follow WWW links 35 from this document in F<.INF> format. If you have EMX docs installed 36 correctly, you can follow library links (you need to have C<view emxbook> 37 working by setting C<EMXBOOK> environment variable as it is described 38 in EMX docs). 39 40 =cut 41 42 Contents (This may be a little bit obsolete) 43 44 perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT. 45 46 NAME 47 SYNOPSIS 48 DESCRIPTION 49 - Target 50 - Other OSes 51 - Prerequisites 52 - Starting Perl programs under OS/2 (and DOS and...) 53 - Starting OS/2 (and DOS) programs under Perl 54 Frequently asked questions 55 - "It does not work" 56 - I cannot run external programs 57 - I cannot embed perl into my program, or use perl.dll from my 58 - `` and pipe-open do not work under DOS. 59 - Cannot start find.exe "pattern" file 60 INSTALLATION 61 - Automatic binary installation 62 - Manual binary installation 63 - Warning 64 Accessing documentation 65 - OS/2 .INF file 66 - Plain text 67 - Manpages 68 - HTML 69 - GNU info files 70 - PDF files 71 - LaTeX docs 72 BUILD 73 - The short story 74 - Prerequisites 75 - Getting perl source 76 - Application of the patches 77 - Hand-editing 78 - Making 79 - Testing 80 - Installing the built perl 81 - a.out-style build 82 Build FAQ 83 - Some / became \ in pdksh. 84 - 'errno' - unresolved external 85 - Problems with tr or sed 86 - Some problem (forget which ;-) 87 - Library ... not found 88 - Segfault in make 89 - op/sprintf test failure 90 Specific (mis)features of OS/2 port 91 - setpriority, getpriority 92 - system() 93 - extproc on the first line 94 - Additional modules: 95 - Prebuilt methods: 96 - Prebuilt variables: 97 - Misfeatures 98 - Modifications 99 - Identifying DLLs 100 - Centralized management of resources 101 Perl flavors 102 - perl.exe 103 - perl_.exe 104 - perl__.exe 105 - perl___.exe 106 - Why strange names? 107 - Why dynamic linking? 108 - Why chimera build? 109 ENVIRONMENT 110 - PERLLIB_PREFIX 111 - PERL_BADLANG 112 - PERL_BADFREE 113 - PERL_SH_DIR 114 - USE_PERL_FLOCK 115 - TMP or TEMP 116 Evolution 117 - Text-mode filehandles 118 - Priorities 119 - DLL name mangling: pre 5.6.2 120 - DLL name mangling: 5.6.2 and beyond 121 - DLL forwarder generation 122 - Threading 123 - Calls to external programs 124 - Memory allocation 125 - Threads 126 BUGS 127 AUTHOR 128 SEE ALSO 129 130 =head1 DESCRIPTION 131 132 =head2 Target 133 134 The target is to make OS/2 one of the best supported platform for 135 using/building/developing Perl and I<Perl applications>, as well as 136 make Perl the best language to use under OS/2. The secondary target is 137 to try to make this work under DOS and Win* as well (but not B<too> hard). 138 139 The current state is quite close to this target. Known limitations: 140 141 =over 5 142 143 =item * 144 145 Some *nix programs use fork() a lot; with the mostly useful flavors of 146 perl for OS/2 (there are several built simultaneously) this is 147 supported; but some flavors do not support this (e.g., when Perl is 148 called from inside REXX). Using fork() after 149 I<use>ing dynamically loading extensions would not work with I<very> old 150 versions of EMX. 151 152 =item * 153 154 You need a separate perl executable F<perl__.exe> (see L<perl__.exe>) 155 if you want to use PM code in your application (as Perl/Tk or OpenGL 156 Perl modules do) without having a text-mode window present. 157 158 While using the standard F<perl.exe> from a text-mode window is possible 159 too, I have seen cases when this causes degradation of the system stability. 160 Using F<perl__.exe> avoids such a degradation. 161 162 =item * 163 164 There is no simple way to access WPS objects. The only way I know 165 is via C<OS2::REXX> and C<SOM> extensions (see L<OS2::REXX>, L<Som>). 166 However, we do not have access to 167 convenience methods of Object-REXX. (Is it possible at all? I know 168 of no Object-REXX API.) The C<SOM> extension (currently in alpha-text) 169 may eventually remove this shortcoming; however, due to the fact that 170 DII is not supported by the C<SOM> module, using C<SOM> is not as 171 convenient as one would like it. 172 173 =back 174 175 Please keep this list up-to-date by informing me about other items. 176 177 =head2 Other OSes 178 179 Since OS/2 port of perl uses a remarkable EMX environment, it can 180 run (and build extensions, and - possibly - be built itself) under any 181 environment which can run EMX. The current list is DOS, 182 DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors, 183 only one works, see L<"perl_.exe">. 184 185 Note that not all features of Perl are available under these 186 environments. This depends on the features the I<extender> - most 187 probably RSX - decided to implement. 188 189 Cf. L<Prerequisites>. 190 191 =head2 Prerequisites 192 193 =over 6 194 195 =item EMX 196 197 EMX runtime is required (may be substituted by RSX). Note that 198 it is possible to make F<perl_.exe> to run under DOS without any 199 external support by binding F<emx.exe>/F<rsx.exe> to it, see L<emxbind>. Note 200 that under DOS for best results one should use RSX runtime, which 201 has much more functions working (like C<fork>, C<popen> and so on). In 202 fact RSX is required if there is no VCPI present. Note the 203 RSX requires DPMI. Many implementations of DPMI are known to be very 204 buggy, beware! 205 206 Only the latest runtime is supported, currently C<0.9d fix 03>. Perl may run 207 under earlier versions of EMX, but this is not tested. 208 209 One can get different parts of EMX from, say 210 211 http://www.leo.org/pub/comp/os/os2/leo/gnu/emx+gcc/ 212 http://powerusersbbs.com/pub/os2/dev/ [EMX+GCC Development] 213 http://hobbes.nmsu.edu/pub/os2/dev/emx/v0.9d/ 214 215 The runtime component should have the name F<emxrt.zip>. 216 217 B<NOTE>. When using F<emx.exe>/F<rsx.exe>, it is enough to have them on your path. One 218 does not need to specify them explicitly (though this 219 220 emx perl_.exe -de 0 221 222 will work as well.) 223 224 =item RSX 225 226 To run Perl on DPMI platforms one needs RSX runtime. This is 227 needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see 228 L<"Other OSes">). RSX would not work with VCPI 229 only, as EMX would, it requires DMPI. 230 231 Having RSX and the latest F<sh.exe> one gets a fully functional 232 B<*nix>-ish environment under DOS, say, C<fork>, C<``> and 233 pipe-C<open> work. In fact, MakeMaker works (for static build), so one 234 can have Perl development environment under DOS. 235 236 One can get RSX from, say 237 238 ftp://ftp.cdrom.com/pub/os2/emx09c/contrib 239 ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc 240 ftp://ftp.leo.org/pub/comp/os/os2/leo/devtools/emx+gcc/contrib 241 242 Contact the author on C<rainer@mathematik.uni-bielefeld.de>. 243 244 The latest F<sh.exe> with DOS hooks is available in 245 246 http://www.ilyaz.org/software/os2/ 247 248 as F<sh_dos.zip> or under similar names starting with C<sh>, C<pdksh> etc. 249 250 =item HPFS 251 252 Perl does not care about file systems, but the perl library contains 253 many files with long names, so to install it intact one needs a file 254 system which supports long file names. 255 256 Note that if you do not plan to build the perl itself, it may be 257 possible to fool EMX to truncate file names. This is not supported, 258 read EMX docs to see how to do it. 259 260 =item pdksh 261 262 To start external programs with complicated command lines (like with 263 pipes in between, and/or quoting of arguments), Perl uses an external 264 shell. With EMX port such shell should be named F<sh.exe>, and located 265 either in the wired-in-during-compile locations (usually F<F:/bin>), 266 or in configurable location (see L<"PERL_SH_DIR">). 267 268 For best results use EMX pdksh. The standard binary (5.2.14 or later) runs 269 under DOS (with L<RSX>) as well, see 270 271 http://www.ilyaz.org/software/os2/ 272 273 =back 274 275 =head2 Starting Perl programs under OS/2 (and DOS and...) 276 277 Start your Perl program F<foo.pl> with arguments C<arg1 arg2 arg3> the 278 same way as on any other platform, by 279 280 perl foo.pl arg1 arg2 arg3 281 282 If you want to specify perl options C<-my_opts> to the perl itself (as 283 opposed to your program), use 284 285 perl -my_opts foo.pl arg1 arg2 arg3 286 287 Alternately, if you use OS/2-ish shell, like CMD or 4os2, put 288 the following at the start of your perl script: 289 290 extproc perl -S -my_opts 291 292 rename your program to F<foo.cmd>, and start it by typing 293 294 foo arg1 arg2 arg3 295 296 Note that because of stupid OS/2 limitations the full path of the perl 297 script is not available when you use C<extproc>, thus you are forced to 298 use C<-S> perl switch, and your script should be on the C<PATH>. As a plus 299 side, if you know a full path to your script, you may still start it 300 with 301 302 perl ../../blah/foo.cmd arg1 arg2 arg3 303 304 (note that the argument C<-my_opts> is taken care of by the C<extproc> line 305 in your script, see L<C<extproc> on the first line>). 306 307 To understand what the above I<magic> does, read perl docs about C<-S> 308 switch - see L<perlrun>, and cmdref about C<extproc>: 309 310 view perl perlrun 311 man perlrun 312 view cmdref extproc 313 help extproc 314 315 or whatever method you prefer. 316 317 There are also endless possibilities to use I<executable extensions> of 318 4os2, I<associations> of WPS and so on... However, if you use 319 *nixish shell (like F<sh.exe> supplied in the binary distribution), 320 you need to follow the syntax specified in L<perlrun/"Switches">. 321 322 Note that B<-S> switch supports scripts with additional extensions 323 F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well. 324 325 =head2 Starting OS/2 (and DOS) programs under Perl 326 327 This is what system() (see L<perlfunc/system>), C<``> (see 328 L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>) 329 are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you 330 do). 331 332 Note however that to use some of these operators you need to have a 333 sh-syntax shell installed (see L<"Pdksh">, 334 L<"Frequently asked questions">), and perl should be able to find it 335 (see L<"PERL_SH_DIR">). 336 337 The cases when the shell is used are: 338 339 =over 340 341 =item 1 342 343 One-argument system() (see L<perlfunc/system>), exec() (see L<perlfunc/exec>) 344 with redirection or shell meta-characters; 345 346 =item 2 347 348 Pipe-open (see L<perlfunc/open>) with the command which contains redirection 349 or shell meta-characters; 350 351 =item 3 352 353 Backticks C<``> (see L<perlop/"I/O Operators">) with the command which contains 354 redirection or shell meta-characters; 355 356 =item 4 357 358 If the executable called by system()/exec()/pipe-open()/C<``> is a script 359 with the "magic" C<#!> line or C<extproc> line which specifies shell; 360 361 =item 5 362 363 If the executable called by system()/exec()/pipe-open()/C<``> is a script 364 without "magic" line, and C<$ENV{EXECSHELL}> is set to shell; 365 366 =item 6 367 368 If the executable called by system()/exec()/pipe-open()/C<``> is not 369 found (is not this remark obsolete?); 370 371 =item 7 372 373 For globbing (see L<perlfunc/glob>, L<perlop/"I/O Operators">) 374 (obsolete? Perl uses builtin globbing nowadays...). 375 376 =back 377 378 For the sake of speed for a common case, in the above algorithms 379 backslashes in the command name are not considered as shell metacharacters. 380 381 Perl starts scripts which begin with cookies 382 C<extproc> or C<#!> directly, without an intervention of shell. Perl uses the 383 same algorithm to find the executable as F<pdksh>: if the path 384 on C<#!> line does not work, and contains C</>, then the directory 385 part of the executable is ignored, and the executable 386 is searched in F<.> and on C<PATH>. To find arguments for these scripts 387 Perl uses a different algorithm than F<pdksh>: up to 3 arguments are 388 recognized, and trailing whitespace is stripped. 389 390 If a script 391 does not contain such a cooky, then to avoid calling F<sh.exe>, Perl uses 392 the same algorithm as F<pdksh>: if C<$ENV{EXECSHELL}> is set, the 393 script is given as the first argument to this command, if not set, then 394 C<$ENV{COMSPEC} /c> is used (or a hardwired guess if C<$ENV{COMSPEC}> is 395 not set). 396 397 When starting scripts directly, Perl uses exactly the same algorithm as for 398 the search of script given by B<-S> command-line option: it will look in 399 the current directory, then on components of C<$ENV{PATH}> using the 400 following order of appended extensions: no extension, F<.cmd>, F<.btm>, 401 F<.bat>, F<.pl>. 402 403 Note that Perl will start to look for scripts only if OS/2 cannot start the 404 specified application, thus C<system 'blah'> will not look for a script if 405 there is an executable file F<blah.exe> I<anywhere> on C<PATH>. In 406 other words, C<PATH> is essentially searched twice: once by the OS for 407 an executable, then by Perl for scripts. 408 409 Note also that executable files on OS/2 can have an arbitrary extension, 410 but F<.exe> will be automatically appended if no dot is present in the name. 411 The workaround is as simple as that: since F<blah.> and F<blah> denote the 412 same file (at list on FAT and HPFS file systems), to start an executable residing in file F<n:/bin/blah> (no 413 extension) give an argument C<n:/bin/blah.> (dot appended) to system(). 414 415 Perl will start PM programs from VIO (=text-mode) Perl process in a 416 separate PM session; 417 the opposite is not true: when you start a non-PM program from a PM 418 Perl process, Perl would not run it in a separate session. If a separate 419 session is desired, either ensure 420 that shell will be used, as in C<system 'cmd /c myprog'>, or start it using 421 optional arguments to system() documented in C<OS2::Process> module. This 422 is considered to be a feature. 423 424 =head1 Frequently asked questions 425 426 =head2 "It does not work" 427 428 Perl binary distributions come with a F<testperl.cmd> script which tries 429 to detect common problems with misconfigured installations. There is a 430 pretty large chance it will discover which step of the installation you 431 managed to goof. C<;-)> 432 433 =head2 I cannot run external programs 434 435 =over 4 436 437 =item * 438 439 Did you run your programs with C<-w> switch? See 440 L<Starting OS/2 (and DOS) programs under Perl>. 441 442 =item * 443 444 Do you try to run I<internal> shell commands, like C<`copy a b`> 445 (internal for F<cmd.exe>), or C<`glob a*b`> (internal for ksh)? You 446 need to specify your shell explicitly, like C<`cmd /c copy a b`>, 447 since Perl cannot deduce which commands are internal to your shell. 448 449 =back 450 451 =head2 I cannot embed perl into my program, or use F<perl.dll> from my 452 program. 453 454 =over 4 455 456 =item Is your program EMX-compiled with C<-Zmt -Zcrtdll>? 457 458 Well, nowadays Perl DLL should be usable from a differently compiled 459 program too... If you can run Perl code from REXX scripts (see 460 L<OS2::REXX>), then there are some other aspect of interaction which 461 are overlooked by the current hackish code to support 462 differently-compiled principal programs. 463 464 If everything else fails, you need to build a stand-alone DLL for 465 perl. Contact me, I did it once. Sockets would not work, as a lot of 466 other stuff. 467 468 =item Did you use L<ExtUtils::Embed>? 469 470 Some time ago I had reports it does not work. Nowadays it is checked 471 in the Perl test suite, so grep F<./t> subdirectory of the build tree 472 (as well as F<*.t> files in the F<./lib> subdirectory) to find how it 473 should be done "correctly". 474 475 =back 476 477 =head2 C<``> and pipe-C<open> do not work under DOS. 478 479 This may a variant of just L<"I cannot run external programs">, or a 480 deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">) 481 for these commands to work, and you may need a port of F<sh.exe> which 482 understands command arguments. One of such ports is listed in 483 L<"Prerequisites"> under RSX. Do not forget to set variable 484 C<L<"PERL_SH_DIR">> as well. 485 486 DPMI is required for RSX. 487 488 =head2 Cannot start C<find.exe "pattern" file> 489 490 The whole idea of the "standard C API to start applications" is that 491 the forms C<foo> and C<"foo"> of program arguments are completely 492 interchangable. F<find> breaks this paradigm; 493 494 find "pattern" file 495 find pattern file 496 497 are not equivalent; F<find> cannot be started directly using the above 498 API. One needs a way to surround the doublequotes in some other 499 quoting construction, necessarily having an extra non-Unixish shell in 500 between. 501 502 Use one of 503 504 system 'cmd', '/c', 'find "pattern" file'; 505 `cmd /c 'find "pattern" file'` 506 507 This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via 508 C<perl.exe>, but this is a price to pay if you want to use 509 non-conforming program. 510 511 =head1 INSTALLATION 512 513 =head2 Automatic binary installation 514 515 The most convenient way of installing a binary distribution of perl is via perl installer 516 F<install.exe>. Just follow the instructions, and 99% of the 517 installation blues would go away. 518 519 Note however, that you need to have F<unzip.exe> on your path, and 520 EMX environment I<running>. The latter means that if you just 521 installed EMX, and made all the needed changes to F<Config.sys>, 522 you may need to reboot in between. Check EMX runtime by running 523 524 emxrev 525 526 Binary installer also creates a folder on your desktop with some useful 527 objects. If you need to change some aspects of the work of the binary 528 installer, feel free to edit the file F<Perl.pkg>. This may be useful 529 e.g., if you need to run the installer many times and do not want to 530 make many interactive changes in the GUI. 531 532 B<Things not taken care of by automatic binary installation:> 533 534 =over 15 535 536 =item C<PERL_BADLANG> 537 538 may be needed if you change your codepage I<after> perl installation, 539 and the new value is not supported by EMX. See L<"PERL_BADLANG">. 540 541 =item C<PERL_BADFREE> 542 543 see L<"PERL_BADFREE">. 544 545 =item F<Config.pm> 546 547 This file resides somewhere deep in the location you installed your 548 perl library, find it out by 549 550 perl -MConfig -le "print $INC{'Config.pm'}" 551 552 While most important values in this file I<are> updated by the binary 553 installer, some of them may need to be hand-edited. I know no such 554 data, please keep me informed if you find one. Moreover, manual 555 changes to the installed version may need to be accompanied by an edit 556 of this file. 557 558 =back 559 560 B<NOTE>. Because of a typo the binary installer of 5.00305 561 would install a variable C<PERL_SHPATH> into F<Config.sys>. Please 562 remove this variable and put C<L<PERL_SH_DIR>> instead. 563 564 =head2 Manual binary installation 565 566 As of version 5.00305, OS/2 perl binary distribution comes split 567 into 11 components. Unfortunately, to enable configurable binary 568 installation, the file paths in the zip files are not absolute, but 569 relative to some directory. 570 571 Note that the extraction with the stored paths is still necessary 572 (default with unzip, specify C<-d> to pkunzip). However, you 573 need to know where to extract the files. You need also to manually 574 change entries in F<Config.sys> to reflect where did you put the 575 files. Note that if you have some primitive unzipper (like 576 C<pkunzip>), you may get a lot of warnings/errors during 577 unzipping. Upgrade to C<(w)unzip>. 578 579 Below is the sample of what to do to reproduce the configuration on my 580 machine. In F<VIEW.EXE> you can press C<Ctrl-Insert> now, and 581 cut-and-paste from the resulting file - created in the directory you 582 started F<VIEW.EXE> from. 583 584 For each component, we mention environment variables related to each 585 installation directory. Either choose directories to match your 586 values of the variables, or create/append-to variables to take into 587 account the directories. 588 589 =over 3 590 591 =item Perl VIO and PM executables (dynamically linked) 592 593 unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin 594 unzip perl_exc.zip *.dll -d f:/emx.add/dll 595 596 (have the directories with C<*.exe> on PATH, and C<*.dll> on 597 LIBPATH); 598 599 =item Perl_ VIO executable (statically linked) 600 601 unzip perl_aou.zip -d f:/emx.add/bin 602 603 (have the directory on PATH); 604 605 =item Executables for Perl utilities 606 607 unzip perl_utl.zip -d f:/emx.add/bin 608 609 (have the directory on PATH); 610 611 =item Main Perl library 612 613 unzip perl_mlb.zip -d f:/perllib/lib 614 615 If this directory is exactly the same as the prefix which was compiled 616 into F<perl.exe>, you do not need to change 617 anything. However, for perl to find the library if you use a different 618 path, you need to 619 C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">. 620 621 =item Additional Perl modules 622 623 unzip perl_ste.zip -d f:/perllib/lib/site_perl/5.8.3/ 624 625 Same remark as above applies. Additionally, if this directory is not 626 one of directories on @INC (and @INC is influenced by C<PERLLIB_PREFIX>), you 627 need to put this 628 directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB> 629 variable. Do not use C<PERL5LIB> unless you have it set already. See 630 L<perl/"ENVIRONMENT">. 631 632 B<[Check whether this extraction directory is still applicable with 633 the new directory structure layout!]> 634 635 =item Tools to compile Perl modules 636 637 unzip perl_blb.zip -d f:/perllib/lib 638 639 Same remark as for F<perl_ste.zip>. 640 641 =item Manpages for Perl and utilities 642 643 unzip perl_man.zip -d f:/perllib/man 644 645 This directory should better be on C<MANPATH>. You need to have a 646 working F<man> to access these files. 647 648 =item Manpages for Perl modules 649 650 unzip perl_mam.zip -d f:/perllib/man 651 652 This directory should better be on C<MANPATH>. You need to have a 653 working man to access these files. 654 655 =item Source for Perl documentation 656 657 unzip perl_pod.zip -d f:/perllib/lib 658 659 This is used by the C<perldoc> program (see L<perldoc>), and may be used to 660 generate HTML documentation usable by WWW browsers, and 661 documentation in zillions of other formats: C<info>, C<LaTeX>, 662 C<Acrobat>, C<FrameMaker> and so on. [Use programs such as 663 F<pod2latex> etc.] 664 665 =item Perl manual in F<.INF> format 666 667 unzip perl_inf.zip -d d:/os2/book 668 669 This directory should better be on C<BOOKSHELF>. 670 671 =item Pdksh 672 673 unzip perl_sh.zip -d f:/bin 674 675 This is used by perl to run external commands which explicitly 676 require shell, like the commands using I<redirection> and I<shell 677 metacharacters>. It is also used instead of explicit F</bin/sh>. 678 679 Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from 680 the above location. 681 682 B<Note.> It may be possible to use some other sh-compatible shell (untested). 683 684 =back 685 686 After you installed the components you needed and updated the 687 F<Config.sys> correspondingly, you need to hand-edit 688 F<Config.pm>. This file resides somewhere deep in the location you 689 installed your perl library, find it out by 690 691 perl -MConfig -le "print $INC{'Config.pm'}" 692 693 You need to correct all the entries which look like file paths (they 694 currently start with C<f:/>). 695 696 =head2 B<Warning> 697 698 The automatic and manual perl installation leave precompiled paths 699 inside perl executables. While these paths are overwriteable (see 700 L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), some people may prefer 701 binary editing of paths inside the executables/DLLs. 702 703 =head1 Accessing documentation 704 705 Depending on how you built/installed perl you may have (otherwise 706 identical) Perl documentation in the following formats: 707 708 =head2 OS/2 F<.INF> file 709 710 Most probably the most convenient form. Under OS/2 view it as 711 712 view perl 713 view perl perlfunc 714 view perl less 715 view perl ExtUtils::MakeMaker 716 717 (currently the last two may hit a wrong location, but this may improve 718 soon). Under Win* see L<"SYNOPSIS">. 719 720 If you want to build the docs yourself, and have I<OS/2 toolkit>, run 721 722 pod2ipf > perl.ipf 723 724 in F</perllib/lib/pod> directory, then 725 726 ipfc /inf perl.ipf 727 728 (Expect a lot of errors during the both steps.) Now move it on your 729 BOOKSHELF path. 730 731 =head2 Plain text 732 733 If you have perl documentation in the source form, perl utilities 734 installed, and GNU groff installed, you may use 735 736 perldoc perlfunc 737 perldoc less 738 perldoc ExtUtils::MakeMaker 739 740 to access the perl documentation in the text form (note that you may get 741 better results using perl manpages). 742 743 Alternately, try running pod2text on F<.pod> files. 744 745 =head2 Manpages 746 747 If you have F<man> installed on your system, and you installed perl 748 manpages, use something like this: 749 750 man perlfunc 751 man 3 less 752 man ExtUtils.MakeMaker 753 754 to access documentation for different components of Perl. Start with 755 756 man perl 757 758 Note that dot (F<.>) is used as a package separator for documentation 759 for packages, and as usual, sometimes you need to give the section - C<3> 760 above - to avoid shadowing by the I<less(1) manpage>. 761 762 Make sure that the directory B<above> the directory with manpages is 763 on our C<MANPATH>, like this 764 765 set MANPATH=c:/man;f:/perllib/man 766 767 for Perl manpages in C<f:/perllib/man/man1/> etc. 768 769 =head2 HTML 770 771 If you have some WWW browser available, installed the Perl 772 documentation in the source form, and Perl utilities, you can build 773 HTML docs. Cd to directory with F<.pod> files, and do like this 774 775 cd f:/perllib/lib/pod 776 pod2html 777 778 After this you can direct your browser the file F<perl.html> in this 779 directory, and go ahead with reading docs, like this: 780 781 explore file:///f:/perllib/lib/pod/perl.html 782 783 Alternatively you may be able to get these docs prebuilt from CPAN. 784 785 =head2 GNU C<info> files 786 787 Users of Emacs would appreciate it very much, especially with 788 C<CPerl> mode loaded. You need to get latest C<pod2texi> from C<CPAN>, 789 or, alternately, the prebuilt info pages. 790 791 =head2 F<PDF> files 792 793 for C<Acrobat> are available on CPAN (may be for slightly older version of 794 perl). 795 796 =head2 C<LaTeX> docs 797 798 can be constructed using C<pod2latex>. 799 800 =head1 BUILD 801 802 Here we discuss how to build Perl under OS/2. There is an alternative 803 (but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>. 804 805 =head2 The short story 806 807 Assume that you are a seasoned porter, so are sure that all the necessary 808 tools are already present on your system, and you know how to get the Perl 809 source distribution. Untar it, change to the extract directory, and 810 811 gnupatch -p0 < os2\diff.configure 812 sh Configure -des -D prefix=f:/perllib 813 make 814 make test 815 make install 816 make aout_test 817 make aout_install 818 819 This puts the executables in f:/perllib/bin. Manually move them to the 820 C<PATH>, manually move the built F<perl*.dll> to C<LIBPATH> (here for 821 Perl DLL F<*> is a not-very-meaningful hex checksum), and run 822 823 make installcmd INSTALLCMDDIR=d:/ir/on/path 824 825 Assuming that the C<man>-files were put on an appropriate location, 826 this completes the installation of minimal Perl system. (The binary 827 distribution contains also a lot of additional modules, and the 828 documentation in INF format.) 829 830 What follows is a detailed guide through these steps. 831 832 =head2 Prerequisites 833 834 You need to have the latest EMX development environment, the full 835 GNU tool suite (gawk renamed to awk, and GNU F<find.exe> 836 earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to 837 check use 838 839 find --version 840 sort --version 841 842 ). You need the latest version of F<pdksh> installed as F<sh.exe>. 843 844 Check that you have B<BSD> libraries and headers installed, and - 845 optionally - Berkeley DB headers and libraries, and crypt. 846 847 Possible locations to get the files: 848 849 ftp://hobbes.nmsu.edu/os2/unix/ 850 ftp://ftp.cdrom.com/pub/os2/unix/ 851 ftp://ftp.cdrom.com/pub/os2/dev32/ 852 ftp://ftp.cdrom.com/pub/os2/emx09c/ 853 854 It is reported that the following archives contain enough utils to 855 build perl: F<gnufutil.zip>, F<gnusutil.zip>, F<gnututil.zip>, F<gnused.zip>, 856 F<gnupatch.zip>, F<gnuawk.zip>, F<gnumake.zip>, F<gnugrep.zip>, F<bsddev.zip> and 857 F<ksh527rt.zip> (or a later version). Note that all these utilities are 858 known to be available from LEO: 859 860 ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu 861 862 Note also that the F<db.lib> and F<db.a> from the EMX distribution 863 are not suitable for multi-threaded compile (even single-threaded 864 flavor of Perl uses multi-threaded C RTL, for 865 compatibility with XFree86-OS/2). Get a corrected one from 866 867 http://www.ilyaz.org/software/os2/db_mt.zip 868 869 If you have I<exactly the same version of Perl> installed already, 870 make sure that no copies or perl are currently running. Later steps 871 of the build may fail since an older version of F<perl.dll> loaded into 872 memory may be found. Running C<make test> becomes meaningless, since 873 the test are checking a previous build of perl (this situation is detected 874 and reported by F<lib/os2_base.t> test). Do not forget to unset 875 C<PERL_EMXLOAD_SEC> in environment. 876 877 Also make sure that you have F</tmp> directory on the current drive, 878 and F<.> directory in your C<LIBPATH>. One may try to correct the 879 latter condition by 880 881 set BEGINLIBPATH .\. 882 883 if you use something like F<CMD.EXE> or latest versions of 884 F<4os2.exe>. (Setting BEGINLIBPATH to just C<.> is ignored by the 885 OS/2 kernel.) 886 887 Make sure your gcc is good for C<-Zomf> linking: run C<omflibs> 888 script in F</emx/lib> directory. 889 890 Check that you have link386 installed. It comes standard with OS/2, 891 but may be not installed due to customization. If typing 892 893 link386 894 895 shows you do not have it, do I<Selective install>, and choose C<Link 896 object modules> in I<Optional system utilities/More>. If you get into 897 link386 prompts, press C<Ctrl-C> to exit. 898 899 =head2 Getting perl source 900 901 You need to fetch the latest perl source (including developers 902 releases). With some probability it is located in 903 904 http://www.cpan.org/src/5.0 905 http://www.cpan.org/src/5.0/unsupported 906 907 If not, you may need to dig in the indices to find it in the directory 908 of the current maintainer. 909 910 Quick cycle of developers release may break the OS/2 build time to 911 time, looking into 912 913 http://www.cpan.org/ports/os2/ 914 915 may indicate the latest release which was publicly released by the 916 maintainer. Note that the release may include some additional patches 917 to apply to the current source of perl. 918 919 Extract it like this 920 921 tar vzxf perl5.00409.tar.gz 922 923 You may see a message about errors while extracting F<Configure>. This is 924 because there is a conflict with a similarly-named file F<configure>. 925 926 Change to the directory of extraction. 927 928 =head2 Application of the patches 929 930 You need to apply the patches in F<./os2/diff.*> like this: 931 932 gnupatch -p0 < os2\diff.configure 933 934 You may also need to apply the patches supplied with the binary 935 distribution of perl. It also makes sense to look on the 936 perl5-porters mailing list for the latest OS/2-related patches (see 937 L<http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/>). Such 938 patches usually contain strings C</os2/> and C<patch>, so it makes 939 sense looking for these strings. 940 941 =head2 Hand-editing 942 943 You may look into the file F<./hints/os2.sh> and correct anything 944 wrong you find there. I do not expect it is needed anywhere. 945 946 =head2 Making 947 948 sh Configure -des -D prefix=f:/perllib 949 950 C<prefix> means: where to install the resulting perl library. Giving 951 correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>, 952 see L<"PERLLIB_PREFIX">. 953 954 I<Ignore the message about missing C<ln>, and about C<-c> option to 955 tr>. The latter is most probably already fixed, if you see it and can trace 956 where the latter spurious warning comes from, please inform me. 957 958 Now 959 960 make 961 962 At some moment the built may die, reporting a I<version mismatch> or 963 I<unable to run F<perl>>. This means that you do not have F<.> in 964 your LIBPATH, so F<perl.exe> cannot find the needed F<perl67B2.dll> (treat 965 these hex digits as line noise). After this is fixed the build 966 should finish without a lot of fuss. 967 968 =head2 Testing 969 970 Now run 971 972 make test 973 974 All tests should succeed (with some of them skipped). If you have the 975 same version of Perl installed, it is crucial that you have C<.> early 976 in your LIBPATH (or in BEGINLIBPATH), otherwise your tests will most 977 probably test the wrong version of Perl. 978 979 Some tests may generate extra messages similar to 980 981 =over 4 982 983 =item A lot of C<bad free> 984 985 in database tests related to Berkeley DB. I<This should be fixed already.> 986 If it persists, you may disable this warnings, see L<"PERL_BADFREE">. 987 988 =item Process terminated by SIGTERM/SIGINT 989 990 This is a standard message issued by OS/2 applications. *nix 991 applications die in silence. It is considered to be a feature. One can 992 easily disable this by appropriate sighandlers. 993 994 However the test engine bleeds these message to screen in unexpected 995 moments. Two messages of this kind I<should> be present during 996 testing. 997 998 =back 999 1000 To get finer test reports, call 1001 1002 perl t/harness 1003 1004 The report with F<io/pipe.t> failing may look like this: 1005 1006 Failed Test Status Wstat Total Fail Failed List of failed 1007 ------------------------------------------------------------ 1008 io/pipe.t 12 1 8.33% 9 1009 7 tests skipped, plus 56 subtests skipped. 1010 Failed 1/195 test scripts, 99.49% okay. 1/6542 subtests failed, 99.98% okay. 1011 1012 The reasons for most important skipped tests are: 1013 1014 =over 8 1015 1016 =item F<op/fs.t> 1017 1018 =over 4 1019 1020 =item 18 1021 1022 Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS 1023 provides only 2sec time granularity (for compatibility with FAT?). 1024 1025 =item 25 1026 1027 Checks C<truncate()> on a filehandle just opened for write - I do not 1028 know why this should or should not work. 1029 1030 =back 1031 1032 =item F<op/stat.t> 1033 1034 Checks C<stat()>. Tests: 1035 1036 =over 4 1037 1038 =item 4 1039 1040 Checks C<atime> and C<mtime> of C<stat()> - unfortunately, HPFS 1041 provides only 2sec time granularity (for compatibility with FAT?). 1042 1043 =back 1044 1045 =back 1046 1047 =head2 Installing the built perl 1048 1049 If you haven't yet moved C<perl*.dll> onto LIBPATH, do it now. 1050 1051 Run 1052 1053 make install 1054 1055 It would put the generated files into needed locations. Manually put 1056 F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your 1057 PATH, F<perl.dll> to a location on your LIBPATH. 1058 1059 Run 1060 1061 make installcmd INSTALLCMDDIR=d:/ir/on/path 1062 1063 to convert perl utilities to F<.cmd> files and put them on 1064 PATH. You need to put F<.EXE>-utilities on path manually. They are 1065 installed in C<$prefix/bin>, here C<$prefix> is what you gave to 1066 F<Configure>, see L<Making>. 1067 1068 If you use C<man>, either move the installed F<*/man/> directories to 1069 your C<MANPATH>, or modify C<MANPATH> to match the location. (One 1070 could have avoided this by providing a correct C<manpath> option to 1071 F<./Configure>, or editing F<./config.sh> between configuring and 1072 making steps.) 1073 1074 =head2 C<a.out>-style build 1075 1076 Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by 1077 1078 make perl_ 1079 1080 test and install by 1081 1082 make aout_test 1083 make aout_install 1084 1085 Manually put F<perl_.exe> to a location on your PATH. 1086 1087 B<Note.> The build process for C<perl_> I<does not know> about all the 1088 dependencies, so you should make sure that anything is up-to-date, 1089 say, by doing 1090 1091 make perl_dll 1092 1093 first. 1094 1095 =head1 Building a binary distribution 1096 1097 [This section provides a short overview only...] 1098 1099 Building should proceed differently depending on whether the version of perl 1100 you install is already present and used on your system, or is a new version 1101 not yet used. The description below assumes that the version is new, so 1102 installing its DLLs and F<.pm> files will not disrupt the operation of your 1103 system even if some intermediate steps are not yet fully working. 1104 1105 The other cases require a little bit more convoluted procedures. Below I 1106 suppose that the current version of Perl is C<5.8.2>, so the executables are 1107 named accordingly. 1108 1109 =over 1110 1111 =item 1. 1112 1113 Fully build and test the Perl distribution. Make sure that no tests are 1114 failing with C<test> and C<aout_test> targets; fix the bugs in Perl and 1115 the Perl test suite detected by these tests. Make sure that C<all_test> 1116 make target runs as clean as possible. Check that C<os2/perlrexx.cmd> 1117 runs fine. 1118 1119 =item 2. 1120 1121 Fully install Perl, including C<installcmd> target. Copy the generated DLLs 1122 to C<LIBPATH>; copy the numbered Perl executables (as in F<perl5.8.2.exe>) 1123 to C<PATH>; copy C<perl_.exe> to C<PATH> as C<perl_5.8.2.exe>. Think whether 1124 you need backward-compatibility DLLs. In most cases you do not need to install 1125 them yet; but sometime this may simplify the following steps. 1126 1127 =item 3. 1128 1129 Make sure that C<CPAN.pm> can download files from CPAN. If not, you may need 1130 to manually install C<Net::FTP>. 1131 1132 =item 4. 1133 1134 Install the bundle C<Bundle::OS2_default> 1135 1136 perl5.8.2 -MCPAN -e "install Bundle::OS2_default" < nul |& tee 00cpan_i_1 1137 1138 This may take a couple of hours on 1GHz processor (when run the first time). 1139 And this should not be necessarily a smooth procedure. Some modules may not 1140 specify required dependencies, so one may need to repeat this procedure several 1141 times until the results stabilize. 1142 1143 perl5.8.2 -MCPAN -e "install Bundle::OS2_default" < nul |& tee 00cpan_i_2 1144 perl5.8.2 -MCPAN -e "install Bundle::OS2_default" < nul |& tee 00cpan_i_3 1145 1146 Even after they stabilize, some tests may fail. 1147 1148 Fix as many discovered bugs as possible. Document all the bugs which are not 1149 fixed, and all the failures with unknown reasons. Inspect the produced logs 1150 F<00cpan_i_1> to find suspiciously skipped tests, and other fishy events. 1151 1152 Keep in mind that I<installation> of some modules may fail too: for example, 1153 the DLLs to update may be already loaded by F<CPAN.pm>. Inspect the C<install> 1154 logs (in the example above F<00cpan_i_1> etc) for errors, and install things 1155 manually, as in 1156 1157 cd $CPANHOME/.cpan/build/Digest-MD5-2.31 1158 make install 1159 1160 Some distributions may fail some tests, but you may want to install them 1161 anyway (as above, or via C<force install> command of C<CPAN.pm> shell-mode). 1162 1163 Since this procedure may take quite a long time to complete, it makes sense 1164 to "freeze" your CPAN configuration by disabling periodic updates of the 1165 local copy of CPAN index: set C<index_expire> to some big value (I use 365), 1166 then save the settings 1167 1168 CPAN> o conf index_expire 365 1169 CPAN> o conf commit 1170 1171 Reset back to the default value C<1> when you are finished. 1172 1173 =item 5. 1174 1175 When satisfied with the results, rerun the C<installcmd> target. Now you 1176 can copy C<perl5.8.2.exe> to C<perl.exe>, and install the other OMF-build 1177 executables: C<perl__.exe> etc. They are ready to be used. 1178 1179 =item 6. 1180 1181 Change to the C<./pod> directory of the build tree, download the Perl logo 1182 F<CamelGrayBig.BMP>, and run 1183 1184 ( perl2ipf > perl.ipf ) |& tee 00ipf 1185 ipfc /INF perl.ipf |& tee 00inf 1186 1187 This produces the Perl docs online book C<perl.INF>. Install in on 1188 C<BOOKSHELF> path. 1189 1190 =item 7. 1191 1192 Now is the time to build statically linked executable F<perl_.exe> which 1193 includes newly-installed via C<Bundle::OS2_default> modules. Doing testing 1194 via C<CPAN.pm> is going to be painfully slow, since it statically links 1195 a new executable per XS extension. 1196 1197 Here is a possible workaround: create a toplevel F<Makefile.PL> in 1198 F<$CPANHOME/.cpan/build/> with contents being (compare with L<Making 1199 executables with a custom collection of statically loaded extensions>) 1200 1201 use ExtUtils::MakeMaker; 1202 WriteMakefile NAME => 'dummy'; 1203 1204 execute this as 1205 1206 perl_5.8.2.exe Makefile.PL <nul |& tee 00aout_c1 1207 make -k all test <nul |& 00aout_t1 1208 1209 Again, this procedure should not be absolutely smooth. Some C<Makefile.PL>'s 1210 in subdirectories may be buggy, and would not run as "child" scripts. The 1211 interdependency of modules can strike you; however, since non-XS modules 1212 are already installed, the prerequisites of most modules have a very good 1213 chance to be present. 1214 1215 If you discover some glitches, move directories of problematic modules to a 1216 different location; if these modules are non-XS modules, you may just ignore 1217 them - they are already installed; the remaining, XS, modules you need to 1218 install manually one by one. 1219 1220 After each such removal you need to rerun the C<Makefile.PL>/C<make> process; 1221 usually this procedure converges soon. (But be sure to convert all the 1222 necessary external C libraries from F<.lib> format to F<.a> format: run one of 1223 1224 emxaout foo.lib 1225 emximp -o foo.a foo.lib 1226 1227 whichever is appropriate.) Also, make sure that the DLLs for external 1228 libraries are usable with with executables compiled without C<-Zmtd> options. 1229 1230 When you are sure that only a few subdirectories 1231 lead to failures, you may want to add C<-j4> option to C<make> to speed up 1232 skipping subdirectories with already finished build. 1233 1234 When you are satisfied with the results of tests, install the build C libraries 1235 for extensions: 1236 1237 make install |& tee 00aout_i 1238 1239 Now you can rename the file F<./perl.exe> generated during the last phase 1240 to F<perl_5.8.2.exe>; place it on C<PATH>; if there is an inter-dependency 1241 between some XS modules, you may need to repeat the C<test>/C<install> loop 1242 with this new executable and some excluded modules - until the procedure 1243 converges. 1244 1245 Now you have all the necessary F<.a> libraries for these Perl modules in the 1246 places where Perl builder can find it. Use the perl builder: change to an 1247 empty directory, create a "dummy" F<Makefile.PL> again, and run 1248 1249 perl_5.8.2.exe Makefile.PL |& tee 00c 1250 make perl |& tee 00p 1251 1252 This should create an executable F<./perl.exe> with all the statically loaded 1253 extensions built in. Compare the generated F<perlmain.c> files to make sure 1254 that during the iterations the number of loaded extensions only increases. 1255 Rename F<./perl.exe> to F<perl_5.8.2.exe> on C<PATH>. 1256 1257 When it converges, you got a functional variant of F<perl_5.8.2.exe>; copy it 1258 to C<perl_.exe>. You are done with generation of the local Perl installation. 1259 1260 =item 8. 1261 1262 Make sure that the installed modules are actually installed in the location 1263 of the new Perl, and are not inherited from entries of @INC given for 1264 inheritance from the older versions of Perl: set C<PERLLIB_582_PREFIX> to 1265 redirect the new version of Perl to a new location, and copy the installed 1266 files to this new location. Redo the tests to make sure that the versions of 1267 modules inherited from older versions of Perl are not needed. 1268 1269 Actually, the log output of L<pod2ipf> during the step 6 gives a very detailed 1270 info about which modules are loaded from which place; so you may use it as 1271 an additional verification tool. 1272 1273 Check that some temporary files did not make into the perl install tree. 1274 Run something like this 1275 1276 pfind . -f "!(/\.(pm|pl|ix|al|h|a|lib|txt|pod|imp|bs|dll|ld|bs|inc|xbm|yml|cgi|uu|e2x|skip|packlist|eg|cfg|html|pub|enc|all|ini|po|pot)$/i or /^\w+$/") | less 1277 1278 in the install tree (both top one and F<sitelib> one). 1279 1280 Compress all the DLLs with F<lxlite>. The tiny F<.exe> can be compressed with 1281 C</c:max> (the bug only appears when there is a fixup in the last 6 bytes of a 1282 page (?); since the tiny executables are much smaller than a page, the bug 1283 will not hit). Do not compress C<perl_.exe> - it would not work under DOS. 1284 1285 =item 9. 1286 1287 Now you can generate the binary distribution. This is done by running the 1288 test of the CPAN distribution C<OS2::SoftInstaller>. Tune up the file 1289 F<test.pl> to suit the layout of current version of Perl first. Do not 1290 forget to pack the necessary external DLLs accordingly. Include the 1291 description of the bugs and test suite failures you could not fix. Include 1292 the small-stack versions of Perl executables from Perl build directory. 1293 1294 Include F<perl5.def> so that people can relink the perl DLL preserving 1295 the binary compatibility, or can create compatibility DLLs. Include the diff 1296 files (C<diff -pu old new>) of fixes you did so that people can rebuild your 1297 version. Include F<perl5.map> so that one can use remote debugging. 1298 1299 =item 10. 1300 1301 Share what you did with the other people. Relax. Enjoy fruits of your work. 1302 1303 =item 11. 1304 1305 Brace yourself for thanks, bug reports, hate mail and spam coming as result 1306 of the previous step. No good deed should remain unpunished! 1307 1308 =back 1309 1310 =head1 Building custom F<.EXE> files 1311 1312 The Perl executables can be easily rebuilt at any moment. Moreover, one can 1313 use the I<embedding> interface (see L<perlembed>) to make very customized 1314 executables. 1315 1316 =head2 Making executables with a custom collection of statically loaded extensions 1317 1318 It is a little bit easier to do so while I<decreasing> the list of statically 1319 loaded extensions. We discuss this case only here. 1320 1321 =over 1322 1323 =item 1. 1324 1325 Change to an empty directory, and create a placeholder <Makefile.PL>: 1326 1327 use ExtUtils::MakeMaker; 1328 WriteMakefile NAME => 'dummy'; 1329 1330 =item 2. 1331 1332 Run it with the flavor of Perl (F<perl.exe> or F<perl_.exe>) you want to 1333 rebuild. 1334 1335 perl_ Makefile.PL 1336 1337 =item 3. 1338 1339 Ask it to create new Perl executable: 1340 1341 make perl 1342 1343 (you may need to manually add C<PERLTYPE=-DPERL_CORE> to this commandline on 1344 some versions of Perl; the symptom is that the command-line globbing does not 1345 work from OS/2 shells with the newly-compiled executable; check with 1346 1347 .\perl.exe -wle "print for @ARGV" * 1348 1349 ). 1350 1351 =item 4. 1352 1353 The previous step created F<perlmain.c> which contains a list of newXS() calls 1354 near the end. Removing unnecessary calls, and rerunning 1355 1356 make perl 1357 1358 will produce a customized executable. 1359 1360 =back 1361 1362 =head2 Making executables with a custom search-paths 1363 1364 The default perl executable is flexible enough to support most usages. 1365 However, one may want something yet more flexible; for example, one may want 1366 to find Perl DLL relatively to the location of the EXE file; or one may want 1367 to ignore the environment when setting the Perl-library search patch, etc. 1368 1369 If you fill comfortable with I<embedding> interface (see L<perlembed>), such 1370 things are easy to do repeating the steps outlined in L<Making 1371 executables with a custom collection of statically loaded extensions>, and 1372 doing more comprehensive edits to main() of F<perlmain.c>. The people with 1373 little desire to understand Perl can just rename main(), and do necessary 1374 modification in a custom main() which calls the renamed function in appropriate 1375 time. 1376 1377 However, there is a third way: perl DLL exports the main() function and several 1378 callbacks to customize the search path. Below is a complete example of a 1379 "Perl loader" which 1380 1381 =over 1382 1383 =item 1. 1384 1385 Looks for Perl DLL in the directory C<$exedir/../dll>; 1386 1387 =item 2. 1388 1389 Prepends the above directory to C<BEGINLIBPATH>; 1390 1391 =item 3. 1392 1393 Fails if the Perl DLL found via C<BEGINLIBPATH> is different from what was 1394 loaded on step 1; e.g., another process could have loaded it from C<LIBPATH> 1395 or from a different value of C<BEGINLIBPATH>. In these cases one needs to 1396 modify the setting of the system so that this other process either does not 1397 run, or loads the DLL from C<BEGINLIBPATH> with C<LIBPATHSTRICT=T> (available 1398 with kernels after September 2000). 1399 1400 =item 4. 1401 1402 Loads Perl library from C<$exedir/../dll/lib/>. 1403 1404 =item 5. 1405 1406 Uses Bourne shell from C<$exedir/../dll/sh/ksh.exe>. 1407 1408 =back 1409 1410 For best results compile the C file below with the same options as the Perl 1411 DLL. However, a lot of functionality will work even if the executable is not 1412 an EMX applications, e.g., if compiled with 1413 1414 gcc -Wall -DDOSISH -DOS2=1 -O2 -s -Zomf -Zsys perl-starter.c -DPERL_DLL_BASENAME=\"perl312F\" -Zstack 8192 -Zlinker /PM:VIO 1415 1416 Here is the sample C file: 1417 1418 #define INCL_DOS 1419 #define INCL_NOPM 1420 /* These are needed for compile if os2.h includes os2tk.h, not os2emx.h */ 1421 #define INCL_DOSPROCESS 1422 #include <os2.h> 1423 1424 #include "EXTERN.h" 1425 #define PERL_IN_MINIPERLMAIN_C 1426 #include "perl.h" 1427 1428 static char *me; 1429 HMODULE handle; 1430 1431 static void 1432 die_with(char *msg1, char *msg2, char *msg3, char *msg4) 1433 { 1434 ULONG c; 1435 char *s = " error: "; 1436 1437 DosWrite(2, me, strlen(me), &c); 1438 DosWrite(2, s, strlen(s), &c); 1439 DosWrite(2, msg1, strlen(msg1), &c); 1440 DosWrite(2, msg2, strlen(msg2), &c); 1441 DosWrite(2, msg3, strlen(msg3), &c); 1442 DosWrite(2, msg4, strlen(msg4), &c); 1443 DosWrite(2, "\r\n", 2, &c); 1444 exit(255); 1445 } 1446 1447 typedef ULONG (*fill_extLibpath_t)(int type, char *pre, char *post, int replace, char *msg); 1448 typedef int (*main_t)(int type, char *argv[], char *env[]); 1449 typedef int (*handler_t)(void* data, int which); 1450 1451 #ifndef PERL_DLL_BASENAME 1452 # define PERL_DLL_BASENAME "perl" 1453 #endif 1454 1455 static HMODULE 1456 load_perl_dll(char *basename) 1457 { 1458 char buf[300], fail[260]; 1459 STRLEN l, dirl; 1460 fill_extLibpath_t f; 1461 ULONG rc_fullname; 1462 HMODULE handle, handle1; 1463 1464 if (_execname(buf, sizeof(buf) - 13) != 0) 1465 die_with("Can't find full path: ", strerror(errno), "", ""); 1466 /* XXXX Fill `me' with new value */ 1467 l = strlen(buf); 1468 while (l && buf[l-1] != '/' && buf[l-1] != '\\') 1469 l--; 1470 dirl = l - 1; 1471 strcpy(buf + l, basename); 1472 l += strlen(basename); 1473 strcpy(buf + l, ".dll"); 1474 if ( (rc_fullname = DosLoadModule(fail, sizeof fail, buf, &handle)) != 0 1475 && DosLoadModule(fail, sizeof fail, basename, &handle) != 0 ) 1476 die_with("Can't load DLL ", buf, "", ""); 1477 if (rc_fullname) 1478 return handle; /* was loaded with short name; all is fine */ 1479 if (DosQueryProcAddr(handle, 0, "fill_extLibpath", (PFN*)&f)) 1480 die_with(buf, ": DLL exports no symbol ", "fill_extLibpath", ""); 1481 buf[dirl] = 0; 1482 if (f(0 /*BEGINLIBPATH*/, buf /* prepend */, NULL /* append */, 1483 0 /* keep old value */, me)) 1484 die_with(me, ": prepending BEGINLIBPATH", "", ""); 1485 if (DosLoadModule(fail, sizeof fail, basename, &handle1) != 0) 1486 die_with(me, ": finding perl DLL again via BEGINLIBPATH", "", ""); 1487 buf[dirl] = '\\'; 1488 if (handle1 != handle) { 1489 if (DosQueryModuleName(handle1, sizeof(fail), fail)) 1490 strcpy(fail, "???"); 1491 die_with(buf, ":\n\tperl DLL via BEGINLIBPATH is different: \n\t", 1492 fail, 1493 "\n\tYou may need to manipulate global BEGINLIBPATH and LIBPATHSTRICT" 1494 "\n\tso that the other copy is loaded via BEGINLIBPATH."); 1495 } 1496 return handle; 1497 } 1498 1499 int 1500 main(int argc, char **argv, char **env) 1501 { 1502 main_t f; 1503 handler_t h; 1504 1505 me = argv[0]; 1506 /**/ 1507 handle = load_perl_dll(PERL_DLL_BASENAME); 1508 1509 if (DosQueryProcAddr(handle, 0, "Perl_OS2_handler_install", (PFN*)&h)) 1510 die_with(PERL_DLL_BASENAME, ": DLL exports no symbol ", "Perl_OS2_handler_install", ""); 1511 if ( !h((void *)"~installprefix", Perlos2_handler_perllib_from) 1512 || !h((void *)"~dll", Perlos2_handler_perllib_to) 1513 || !h((void *)"~dll/sh/ksh.exe", Perlos2_handler_perl_sh) ) 1514 die_with(PERL_DLL_BASENAME, ": Can't install @INC manglers", "", ""); 1515 1516 if (DosQueryProcAddr(handle, 0, "dll_perlmain", (PFN*)&f)) 1517 die_with(PERL_DLL_BASENAME, ": DLL exports no symbol ", "dll_perlmain", ""); 1518 return f(argc, argv, env); 1519 } 1520 1521 1522 =head1 Build FAQ 1523 1524 =head2 Some C</> became C<\> in pdksh. 1525 1526 You have a very old pdksh. See L<Prerequisites>. 1527 1528 =head2 C<'errno'> - unresolved external 1529 1530 You do not have MT-safe F<db.lib>. See L<Prerequisites>. 1531 1532 =head2 Problems with tr or sed 1533 1534 reported with very old version of tr and sed. 1535 1536 =head2 Some problem (forget which ;-) 1537 1538 You have an older version of F<perl.dll> on your LIBPATH, which 1539 broke the build of extensions. 1540 1541 =head2 Library ... not found 1542 1543 You did not run C<omflibs>. See L<Prerequisites>. 1544 1545 =head2 Segfault in make 1546 1547 You use an old version of GNU make. See L<Prerequisites>. 1548 1549 =head2 op/sprintf test failure 1550 1551 This can result from a bug in emx sprintf which was fixed in 0.9d fix 03. 1552 1553 =head1 Specific (mis)features of OS/2 port 1554 1555 =head2 C<setpriority>, C<getpriority> 1556 1557 Note that these functions are compatible with *nix, not with the older 1558 ports of '94 - 95. The priorities are absolute, go from 32 to -95, 1559 lower is quicker. 0 is the default priority. 1560 1561 B<WARNING>. Calling C<getpriority> on a non-existing process could lock 1562 the system before Warp3 fixpak22. Starting with Warp3, Perl will use 1563 a workaround: it aborts getpriority() if the process is not present. 1564 This is not possible on older versions C<2.*>, and has a race 1565 condition anyway. 1566 1567 =head2 C<system()> 1568 1569 Multi-argument form of C<system()> allows an additional numeric 1570 argument. The meaning of this argument is described in 1571 L<OS2::Process>. 1572 1573 When finding a program to run, Perl first asks the OS to look for executables 1574 on C<PATH> (OS/2 adds extension F<.exe> if no extension is present). 1575 If not found, it looks for a script with possible extensions 1576 added in this order: no extension, F<.cmd>, F<.btm>, 1577 F<.bat>, F<.pl>. If found, Perl checks the start of the file for magic 1578 strings C<"#!"> and C<"extproc ">. If found, Perl uses the rest of the 1579 first line as the beginning of the command line to run this script. The 1580 only mangling done to the first line is extraction of arguments (currently 1581 up to 3), and ignoring of the path-part of the "interpreter" name if it can't 1582 be found using the full path. 1583 1584 E.g., C<system 'foo', 'bar', 'baz'> may lead Perl to finding 1585 F<C:/emx/bin/foo.cmd> with the first line being 1586 1587 extproc /bin/bash -x -c 1588 1589 If F</bin/bash.exe> is not found, then Perl looks for an executable F<bash.exe> on 1590 C<PATH>. If found in F<C:/emx.add/bin/bash.exe>, then the above system() is 1591 translated to 1592 1593 system qw(C:/emx.add/bin/bash.exe -x -c C:/emx/bin/foo.cmd bar baz) 1594 1595 One additional translation is performed: instead of F</bin/sh> Perl uses 1596 the hardwired-or-customized shell (see C<L<"PERL_SH_DIR">>). 1597 1598 The above search for "interpreter" is recursive: if F<bash> executable is not 1599 found, but F<bash.btm> is found, Perl will investigate its first line etc. 1600 The only hardwired limit on the recursion depth is implicit: there is a limit 1601 4 on the number of additional arguments inserted before the actual arguments 1602 given to system(). In particular, if no additional arguments are specified 1603 on the "magic" first lines, then the limit on the depth is 4. 1604 1605 If Perl finds that the found executable is of PM type when the 1606 current session is not, it will start the new process in a separate session of 1607 necessary type. Call via C<OS2::Process> to disable this magic. 1608 1609 B<WARNING>. Due to the described logic, you need to explicitly 1610 specify F<.com> extension if needed. Moreover, if the executable 1611 F<perl5.6.1> is requested, Perl will not look for F<perl5.6.1.exe>. 1612 [This may change in the future.] 1613 1614 =head2 C<extproc> on the first line 1615 1616 If the first chars of a Perl script are C<"extproc ">, this line is treated 1617 as C<#!>-line, thus all the switches on this line are processed (twice 1618 if script was started via cmd.exe). See L<perlrun/DESCRIPTION>. 1619 1620 =head2 Additional modules: 1621 1622 L<OS2::Process>, L<OS2::DLL>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. These 1623 modules provide access to additional numeric argument for C<system> 1624 and to the information about the running process, 1625 to DLLs having functions with REXX signature and to the REXX runtime, to 1626 OS/2 databases in the F<.INI> format, and to Extended Attributes. 1627 1628 Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and 1629 C<OS2::FTP>, are included into C<ILYAZ> directory, mirrored on CPAN. 1630 Other OS/2-related extensions are available too. 1631 1632 =head2 Prebuilt methods: 1633 1634 =over 4 1635 1636 =item C<File::Copy::syscopy> 1637 1638 used by C<File::Copy::copy>, see L<File::Copy>. 1639 1640 =item C<DynaLoader::mod2fname> 1641 1642 used by C<DynaLoader> for DLL name mangling. 1643 1644 =item C<Cwd::current_drive()> 1645 1646 Self explanatory. 1647 1648 =item C<Cwd::sys_chdir(name)> 1649 1650 leaves drive as it is. 1651 1652 =item C<Cwd::change_drive(name)> 1653 1654 chanes the "current" drive. 1655 1656 =item C<Cwd::sys_is_absolute(name)> 1657 1658 means has drive letter and is_rooted. 1659 1660 =item C<Cwd::sys_is_rooted(name)> 1661 1662 means has leading C<[/\\]> (maybe after a drive-letter:). 1663 1664 =item C<Cwd::sys_is_relative(name)> 1665 1666 means changes with current dir. 1667 1668 =item C<Cwd::sys_cwd(name)> 1669 1670 Interface to cwd from EMX. Used by C<Cwd::cwd>. 1671 1672 =item C<Cwd::sys_abspath(name, dir)> 1673 1674 Really really odious function to implement. Returns absolute name of 1675 file which would have C<name> if CWD were C<dir>. C<Dir> defaults to the 1676 current dir. 1677 1678 =item C<Cwd::extLibpath([type])> 1679 1680 Get current value of extended library search path. If C<type> is 1681 present and positive, works with C<END_LIBPATH>, if negative, works 1682 with C<LIBPATHSTRICT>, otherwise with C<BEGIN_LIBPATH>. 1683 1684 =item C<Cwd::extLibpath_set( path [, type ] )> 1685 1686 Set current value of extended library search path. If C<type> is 1687 present and positive, works with <END_LIBPATH>, if negative, works 1688 with C<LIBPATHSTRICT>, otherwise with C<BEGIN_LIBPATH>. 1689 1690 =item C<OS2::Error(do_harderror,do_exception)> 1691 1692 Returns C<undef> if it was not called yet, otherwise bit 1 is 1693 set if on the previous call do_harderror was enabled, bit 1694 2 is set if on previous call do_exception was enabled. 1695 1696 This function enables/disables error popups associated with 1697 hardware errors (Disk not ready etc.) and software exceptions. 1698 1699 I know of no way to find out the state of popups I<before> the first call 1700 to this function. 1701 1702 =item C<OS2::Errors2Drive(drive)> 1703 1704 Returns C<undef> if it was not called yet, otherwise return false if errors 1705 were not requested to be written to a hard drive, or the drive letter if 1706 this was requested. 1707 1708 This function may redirect error popups associated with hardware errors 1709 (Disk not ready etc.) and software exceptions to the file POPUPLOG.OS2 at 1710 the root directory of the specified drive. Overrides OS2::Error() specified 1711 by individual programs. Given argument undef will disable redirection. 1712 1713 Has global effect, persists after the application exits. 1714 1715 I know of no way to find out the state of redirection of popups to the disk 1716 I<before> the first call to this function. 1717 1718 =item OS2::SysInfo() 1719 1720 Returns a hash with system information. The keys of the hash are 1721 1722 MAX_PATH_LENGTH, MAX_TEXT_SESSIONS, MAX_PM_SESSIONS, 1723 MAX_VDM_SESSIONS, BOOT_DRIVE, DYN_PRI_VARIATION, 1724 MAX_WAIT, MIN_SLICE, MAX_SLICE, PAGE_SIZE, 1725 VERSION_MAJOR, VERSION_MINOR, VERSION_REVISION, 1726 MS_COUNT, TIME_LOW, TIME_HIGH, TOTPHYSMEM, TOTRESMEM, 1727 TOTAVAILMEM, MAXPRMEM, MAXSHMEM, TIMER_INTERVAL, 1728 MAX_COMP_LENGTH, FOREGROUND_FS_SESSION, 1729 FOREGROUND_PROCESS 1730 1731 =item OS2::BootDrive() 1732 1733 Returns a letter without colon. 1734 1735 =item C<OS2::MorphPM(serve)>, C<OS2::UnMorphPM(serve)> 1736 1737 Transforms the current application into a PM application and back. 1738 The argument true means that a real message loop is going to be served. 1739 OS2::MorphPM() returns the PM message queue handle as an integer. 1740 1741 See L<"Centralized management of resources"> for additional details. 1742 1743 =item C<OS2::Serve_Messages(force)> 1744 1745 Fake on-demand retrieval of outstanding PM messages. If C<force> is false, 1746 will not dispatch messages if a real message loop is known to 1747 be present. Returns number of messages retrieved. 1748 1749 Dies with "QUITing..." if WM_QUIT message is obtained. 1750 1751 =item C<OS2::Process_Messages(force [, cnt])> 1752 1753 Retrieval of PM messages until window creation/destruction. 1754 If C<force> is false, will not dispatch messages if a real message loop 1755 is known to be present. 1756 1757 Returns change in number of windows. If C<cnt> is given, 1758 it is incremented by the number of messages retrieved. 1759 1760 Dies with "QUITing..." if WM_QUIT message is obtained. 1761 1762 =item C<OS2::_control87(new,mask)> 1763 1764 the same as L<_control87(3)> of EMX. Takes integers as arguments, returns 1765 the previous coprocessor control word as an integer. Only bits in C<new> which 1766 are present in C<mask> are changed in the control word. 1767 1768 =item OS2::get_control87() 1769 1770 gets the coprocessor control word as an integer. 1771 1772 =item C<OS2::set_control87_em(new=MCW_EM,mask=MCW_EM)> 1773 1774 The variant of OS2::_control87() with default values good for 1775 handling exception mask: if no C<mask>, uses exception mask part of C<new> 1776 only. If no C<new>, disables all the floating point exceptions. 1777 1778 See L<"Misfeatures"> for details. 1779 1780 =item C<OS2::DLLname([how [, \&xsub]])> 1781 1782 Gives the information about the Perl DLL or the DLL containing the C 1783 function bound to by C<&xsub>. The meaning of C<how> is: default (2): 1784 full name; 0: handle; 1: module name. 1785 1786 =back 1787 1788 (Note that some of these may be moved to different libraries - 1789 eventually). 1790 1791 1792 =head2 Prebuilt variables: 1793 1794 =over 4 1795 1796 =item $OS2::emx_rev 1797 1798 numeric value is the same as _emx_rev of EMX, a string value the same 1799 as _emx_vprt (similar to C<0.9c>). 1800 1801 =item $OS2::emx_env 1802 1803 same as _emx_env of EMX, a number similar to 0x8001. 1804 1805 =item $OS2::os_ver 1806 1807 a number C<OS_MAJOR + 0.001 * OS_MINOR>. 1808 1809 =item $OS2::is_aout 1810 1811 true if the Perl library was compiled in AOUT format. 1812 1813 =item $OS2::can_fork 1814 1815 true if the current executable is an AOUT EMX executable, so Perl can 1816 fork. Do not use this, use the portable check for 1817 $Config::Config{dfork}. 1818 1819 =item $OS2::nsyserror 1820 1821 This variable (default is 1) controls whether to enforce the contents 1822 of $^E to start with C<SYS0003>-like id. If set to 0, then the string 1823 value of $^E is what is available from the OS/2 message file. (Some 1824 messages in this file have an C<SYS0003>-like id prepended, some not.) 1825 1826 =back 1827 1828 =head2 Misfeatures 1829 1830 =over 4 1831 1832 =item * 1833 1834 Since L<flock(3)> is present in EMX, but is not functional, it is 1835 emulated by perl. To disable the emulations, set environment variable 1836 C<USE_PERL_FLOCK=0>. 1837 1838 =item * 1839 1840 Here is the list of things which may be "broken" on 1841 EMX (from EMX docs): 1842 1843 =over 4 1844 1845 =item * 1846 1847 The functions L<recvmsg(3)>, L<sendmsg(3)>, and L<socketpair(3)> are not 1848 implemented. 1849 1850 =item * 1851 1852 L<sock_init(3)> is not required and not implemented. 1853 1854 =item * 1855 1856 L<flock(3)> is not yet implemented (dummy function). (Perl has a workaround.) 1857 1858 =item * 1859 1860 L<kill(3)>: Special treatment of PID=0, PID=1 and PID=-1 is not implemented. 1861 1862 =item * 1863 1864 L<waitpid(3)>: 1865 1866 WUNTRACED 1867 Not implemented. 1868 waitpid() is not implemented for negative values of PID. 1869 1870 =back 1871 1872 Note that C<kill -9> does not work with the current version of EMX. 1873 1874 =item * 1875 1876 See L<"Text-mode filehandles">. 1877 1878 =item * 1879 1880 Unix-domain sockets on OS/2 live in a pseudo-file-system C</sockets/...>. 1881 To avoid a failure to create a socket with a name of a different form, 1882 C<"/socket/"> is prepended to the socket name (unless it starts with this 1883 already). 1884 1885 This may lead to problems later in case the socket is accessed via the 1886 "usual" file-system calls using the "initial" name. 1887 1888 =item * 1889 1890 Apparently, IBM used a compiler (for some period of time around '95?) which 1891 changes FP mask right and left. This is not I<that> bad for IBM's 1892 programs, but the same compiler was used for DLLs which are used with 1893 general-purpose applications. When these DLLs are used, the state of 1894 floating-point flags in the application is not predictable. 1895 1896 What is much worse, some DLLs change the floating point flags when in 1897 _DLLInitTerm() (e.g., F<TCP32IP>). This means that even if you do not I<call> 1898 any function in the DLL, just the act of loading this DLL will reset your 1899 flags. What is worse, the same compiler was used to compile some HOOK DLLs. 1900 Given that HOOK dlls are executed in the context of I<all> the applications 1901 in the system, this means a complete unpredictablity of floating point 1902 flags on systems using such HOOK DLLs. E.g., F<GAMESRVR.DLL> of B<DIVE> 1903 origin changes the floating point flags on each write to the TTY of a VIO 1904 (windowed text-mode) applications. 1905 1906 Some other (not completely debugged) situations when FP flags change include 1907 some video drivers (?), and some operations related to creation of the windows. 1908 People who code B<OpenGL> may have more experience on this. 1909 1910 Perl is generally used in the situation when all the floating-point 1911 exceptions are ignored, as is the default under EMX. If they are not ignored, 1912 some benign Perl programs would get a C<SIGFPE> and would die a horrible death. 1913 1914 To circumvent this, Perl uses two hacks. They help against I<one> type of 1915 damage only: FP flags changed when loading a DLL. 1916 1917 One of the hacks is to disable floating point exceptions on Perl startup (as 1918 is the default with EMX). This helps only with compile-time-linked DLLs 1919 changing the flags before main() had a chance to be called. 1920 1921 The other hack is to restore FP flags after a call to dlopen(). This helps 1922 against similar damage done by DLLs _DLLInitTerm() at runtime. Currently 1923 no way to switch these hacks off is provided. 1924 1925 =back 1926 1927 =head2 Modifications 1928 1929 Perl modifies some standard C library calls in the following ways: 1930 1931 =over 9 1932 1933 =item C<popen> 1934 1935 C<my_popen> uses F<sh.exe> if shell is required, cf. L<"PERL_SH_DIR">. 1936 1937 =item C<tmpnam> 1938 1939 is created using C<TMP> or C<TEMP> environment variable, via 1940 C<tempnam>. 1941 1942 =item C<tmpfile> 1943 1944 If the current directory is not writable, file is created using modified 1945 C<tmpnam>, so there may be a race condition. 1946 1947 =item C<ctermid> 1948 1949 a dummy implementation. 1950 1951 =item C<stat> 1952 1953 C<os2_stat> special-cases F</dev/tty> and F</dev/con>. 1954 1955 =item C<mkdir>, C<rmdir> 1956 1957 these EMX functions do not work if the path contains a trailing C</>. 1958 Perl contains a workaround for this. 1959 1960 =item C<flock> 1961 1962 Since L<flock(3)> is present in EMX, but is not functional, it is 1963 emulated by perl. To disable the emulations, set environment variable 1964 C<USE_PERL_FLOCK=0>. 1965 1966 =back 1967 1968 =head2 Identifying DLLs 1969 1970 All the DLLs built with the current versions of Perl have ID strings 1971 identifying the name of the extension, its version, and the version 1972 of Perl required for this DLL. Run C<bldlevel DLL-name> to find this 1973 info. 1974 1975 =head2 Centralized management of resources 1976 1977 Since to call certain OS/2 API one needs to have a correctly initialized 1978 C<Win> subsystem, OS/2-specific extensions may require getting C<HAB>s and 1979 C<HMQ>s. If an extension would do it on its own, another extension could 1980 fail to initialize. 1981 1982 Perl provides a centralized management of these resources: 1983 1984 =over 1985 1986 =item C<HAB> 1987 1988 To get the HAB, the extension should call C<hab = perl_hab_GET()> in C. After 1989 this call is performed, C<hab> may be accessed as C<Perl_hab>. There is 1990 no need to release the HAB after it is used. 1991 1992 If by some reasons F<perl.h> cannot be included, use 1993 1994 extern int Perl_hab_GET(void); 1995 1996 instead. 1997 1998 =item C<HMQ> 1999 2000 There are two cases: 2001 2002 =over 2003 2004 =item * 2005 2006 the extension needs an C<HMQ> only because some API will not work otherwise. 2007 Use C<serve = 0> below. 2008 2009 =item * 2010 2011 the extension needs an C<HMQ> since it wants to engage in a PM event loop. 2012 Use C<serve = 1> below. 2013 2014 =back 2015 2016 To get an C<HMQ>, the extension should call C<hmq = perl_hmq_GET(serve)> in C. 2017 After this call is performed, C<hmq> may be accessed as C<Perl_hmq>. 2018 2019 To signal to Perl that HMQ is not needed any more, call 2020 C<perl_hmq_UNSET(serve)>. Perl process will automatically morph/unmorph itself 2021 into/from a PM process if HMQ is needed/not-needed. Perl will automatically 2022 enable/disable C<WM_QUIT> message during shutdown if the message queue is 2023 served/not-served. 2024 2025 B<NOTE>. If during a shutdown there is a message queue which did not disable 2026 WM_QUIT, and which did not process the received WM_QUIT message, the 2027 shutdown will be automatically cancelled. Do not call C<perl_hmq_GET(1)> 2028 unless you are going to process messages on an orderly basis. 2029 2030 =item * Treating errors reported by OS/2 API 2031 2032 There are two principal conventions (it is useful to call them C<Dos*> 2033 and C<Win*> - though this part of the function signature is not always 2034 determined by the name of the API) of reporting the error conditions 2035 of OS/2 API. Most of C<Dos*> APIs report the error code as the result 2036 of the call (so 0 means success, and there are many types of errors). 2037 Most of C<Win*> API report success/fail via the result being 2038 C<TRUE>/C<FALSE>; to find the reason for the failure one should call 2039 WinGetLastError() API. 2040 2041 Some C<Win*> entry points also overload a "meaningful" return value 2042 with the error indicator; having a 0 return value indicates an error. 2043 Yet some other C<Win*> entry points overload things even more, and 0 2044 return value may mean a successful call returning a valid value 0, as 2045 well as an error condition; in the case of a 0 return value one should 2046 call WinGetLastError() API to distinguish a successful call from a 2047 failing one. 2048 2049 By convention, all the calls to OS/2 API should indicate their 2050 failures by resetting $^E. All the Perl-accessible functions which 2051 call OS/2 API may be broken into two classes: some die()s when an API 2052 error is encountered, the other report the error via a false return 2053 value (of course, this does not concern Perl-accessible functions 2054 which I<expect> a failure of the OS/2 API call, having some workarounds 2055 coded). 2056 2057 Obviously, in the situation of the last type of the signature of an OS/2 2058 API, it is must more convenient for the users if the failure is 2059 indicated by die()ing: one does not need to check $^E to know that 2060 something went wrong. If, however, this solution is not desirable by 2061 some reason, the code in question should reset $^E to 0 before making 2062 this OS/2 API call, so that the caller of this Perl-accessible 2063 function has a chance to distinguish a success-but-0-return value from 2064 a failure. (One may return undef as an alternative way of reporting 2065 an error.) 2066 2067 The macros to simplify this type of error propagation are 2068 2069 =over 2070 2071 =item C<CheckOSError(expr)> 2072 2073 Returns true on error, sets $^E. Expects expr() be a call of 2074 C<Dos*>-style API. 2075 2076 =item C<CheckWinError(expr)> 2077 2078 Returns true on error, sets $^E. Expects expr() be a call of 2079 C<Win*>-style API. 2080 2081 =item C<SaveWinError(expr)> 2082 2083 Returns C<expr>, sets $^E from WinGetLastError() if C<expr> is false. 2084 2085 =item C<SaveCroakWinError(expr,die,name1,name2)> 2086 2087 Returns C<expr>, sets $^E from WinGetLastError() if C<expr> is false, 2088 and die()s if C<die> and $^E are true. The message to die is the 2089 concatenated strings C<name1> and C<name2>, separated by C<": "> from 2090 the contents of $^E. 2091 2092 =item C<WinError_2_Perl_rc> 2093 2094 Sets C<Perl_rc> to the return value of WinGetLastError(). 2095 2096 =item C<FillWinError> 2097 2098 Sets C<Perl_rc> to the return value of WinGetLastError(), and sets $^E 2099 to the corresponding value. 2100 2101 =item C<FillOSError(rc)> 2102 2103 Sets C<Perl_rc> to C<rc>, and sets $^E to the corresponding value. 2104 2105 =back 2106 2107 =item * Loading DLLs and ordinals in DLLs 2108 2109 Some DLLs are only present in some versions of OS/2, or in some 2110 configurations of OS/2. Some exported entry points are present only 2111 in DLLs shipped with some versions of OS/2. If these DLLs and entry 2112 points were linked directly for a Perl executable/DLL or from a Perl 2113 extensions, this binary would work only with the specified 2114 versions/setups. Even if these entry points were not needed, the 2115 I<load> of the executable (or DLL) would fail. 2116 2117 For example, many newer useful APIs are not present in OS/2 v2; many 2118 PM-related APIs require DLLs not available on floppy-boot setup. 2119 2120 To make these calls fail I<only when the calls are executed>, one 2121 should call these API via a dynamic linking API. There is a subsystem 2122 in Perl to simplify such type of calls. A large number of entry 2123 points available for such linking is provided (see C<entries_ordinals> 2124 - and also C<PMWIN_entries> - in F<os2ish.h>). These ordinals can be 2125 accessed via the APIs: 2126 2127 CallORD(), DeclFuncByORD(), DeclVoidFuncByORD(), 2128 DeclOSFuncByORD(), DeclWinFuncByORD(), AssignFuncPByORD(), 2129 DeclWinFuncByORD_CACHE(), DeclWinFuncByORD_CACHE_survive(), 2130 DeclWinFuncByORD_CACHE_resetError_survive(), 2131 DeclWinFunc_CACHE(), DeclWinFunc_CACHE_resetError(), 2132 DeclWinFunc_CACHE_survive(), DeclWinFunc_CACHE_resetError_survive() 2133 2134 See the header files and the C code in the supplied OS/2-related 2135 modules for the details on usage of these functions. 2136 2137 Some of these functions also combine dynaloading semantic with the 2138 error-propagation semantic discussed above. 2139 2140 =back 2141 2142 =head1 Perl flavors 2143 2144 Because of idiosyncrasies of OS/2 one cannot have all the eggs in the 2145 same basket (though EMX environment tries hard to overcome this 2146 limitations, so the situation may somehow improve). There are 4 2147 executables for Perl provided by the distribution: 2148 2149 =head2 F<perl.exe> 2150 2151 The main workhorse. This is a chimera executable: it is compiled as an 2152 C<a.out>-style executable, but is linked with C<omf>-style dynamic 2153 library F<perl.dll>, and with dynamic CRT DLL. This executable is a 2154 VIO application. 2155 2156 It can load perl dynamic extensions, and it can fork(). 2157 2158 B<Note.> Keep in mind that fork() is needed to open a pipe to yourself. 2159 2160 =head2 F<perl_.exe> 2161 2162 This is a statically linked C<a.out>-style executable. It cannot 2163 load dynamic Perl extensions. The executable supplied in binary 2164 distributions has a lot of extensions prebuilt, thus the above restriction is 2165 important only if you use custom-built extensions. This executable is a VIO 2166 application. 2167 2168 I<This is the only executable with does not require OS/2.> The 2169 friends locked into C<M$> world would appreciate the fact that this 2170 executable runs under DOS, Win0.3*, Win0.95 and WinNT with an 2171 appropriate extender. See L<"Other OSes">. 2172 2173 =head2 F<perl__.exe> 2174 2175 This is the same executable as F<perl___.exe>, but it is a PM 2176 application. 2177 2178 B<Note.> Usually (unless explicitly redirected during the startup) 2179 STDIN, STDERR, and STDOUT of a PM 2180 application are redirected to F<nul>. However, it is possible to I<see> 2181 them if you start C<perl__.exe> from a PM program which emulates a 2182 console window, like I<Shell mode> of Emacs or EPM. Thus it I<is 2183 possible> to use Perl debugger (see L<perldebug>) to debug your PM 2184 application (but beware of the message loop lockups - this will not 2185 work if you have a message queue to serve, unless you hook the serving 2186 into the getc() function of the debugger). 2187 2188 Another way to see the output of a PM program is to run it as 2189 2190 pm_prog args 2>&1 | cat - 2191 2192 with a shell I<different> from F<cmd.exe>, so that it does not create 2193 a link between a VIO session and the session of C<pm_porg>. (Such a link 2194 closes the VIO window.) E.g., this works with F<sh.exe> - or with Perl! 2195 2196 open P, 'pm_prog args 2>&1 |' or die; 2197 print while <P>; 2198 2199 The flavor F<perl__.exe> is required if you want to start your program without 2200 a VIO window present, but not C<detach>ed (run C<help detach> for more info). 2201 Very useful for extensions which use PM, like C<Perl/Tk> or C<OpenGL>. 2202 2203 Note also that the differences between PM and VIO executables are only 2204 in the I<default> behaviour. One can start I<any> executable in 2205 I<any> kind of session by using the arguments C</fs>, C</pm> or 2206 C</win> switches of the command C<start> (of F<CMD.EXE> or a similar 2207 shell). Alternatively, one can use the numeric first argument of the 2208 C<system> Perl function (see L<OS2::Process>). 2209 2210 =head2 F<perl___.exe> 2211 2212 This is an C<omf>-style executable which is dynamically linked to 2213 F<perl.dll> and CRT DLL. I know no advantages of this executable 2214 over C<perl.exe>, but it cannot fork() at all. Well, one advantage is 2215 that the build process is not so convoluted as with C<perl.exe>. 2216 2217 It is a VIO application. 2218 2219 =head2 Why strange names? 2220 2221 Since Perl processes the C<#!>-line (cf. 2222 L<perlrun/DESCRIPTION>, L<perlrun/Switches>, 2223 L<perldiag/"Not a perl script">, 2224 L<perldiag/"No Perl script found in input">), it should know when a 2225 program I<is a Perl>. There is some naming convention which allows 2226 Perl to distinguish correct lines from wrong ones. The above names are 2227 almost the only names allowed by this convention which do not contain 2228 digits (which have absolutely different semantics). 2229 2230 =head2 Why dynamic linking? 2231 2232 Well, having several executables dynamically linked to the same huge 2233 library has its advantages, but this would not substantiate the 2234 additional work to make it compile. The reason is the complicated-to-developers 2235 but very quick and convenient-to-users "hard" dynamic linking used by OS/2. 2236 2237 There are two distinctive features of the dyna-linking model of OS/2: 2238 first, all the references to external functions are resolved at the compile time; 2239 second, there is no runtime fixup of the DLLs after they are loaded into memory. 2240 The first feature is an enormous advantage over other models: it avoids 2241 conflicts when several DLLs used by an application export entries with 2242 the same name. In such cases "other" models of dyna-linking just choose 2243 between these two entry points using some random criterion - with predictable 2244 disasters as results. But it is the second feature which requires the build 2245 of F<perl.dll>. 2246 2247 The address tables of DLLs are patched only once, when they are 2248 loaded. The addresses of the entry points into DLLs are guaranteed to be 2249 the same for all the programs which use the same DLL. This removes the 2250 runtime fixup - once DLL is loaded, its code is read-only. 2251 2252 While this allows some (significant?) performance advantages, this makes life 2253 much harder for developers, since the above scheme makes it impossible 2254 for a DLL to be "linked" to a symbol in the F<.EXE> file. Indeed, this 2255 would need a DLL to have different relocations tables for the 2256 (different) executables which use this DLL. 2257 2258 However, a dynamically loaded Perl extension is forced to use some symbols 2259 from the perl 2260 executable, e.g., to know how to find the arguments to the functions: 2261 the arguments live on the perl 2262 internal evaluation stack. The solution is to put the main code of 2263 the interpreter into a DLL, and make the F<.EXE> file which just loads 2264 this DLL into memory and supplies command-arguments. The extension DLL 2265 cannot link to symbols in F<.EXE>, but it has no problem linking 2266 to symbols in the F<.DLL>. 2267 2268 This I<greatly> increases the load time for the application (as well as 2269 complexity of the compilation). Since interpreter is in a DLL, 2270 the C RTL is basically forced to reside in a DLL as well (otherwise 2271 extensions would not be able to use CRT). There are some advantages if 2272 you use different flavors of perl, such as running F<perl.exe> and 2273 F<perl__.exe> simultaneously: they share the memory of F<perl.dll>. 2274 2275 B<NOTE>. There is one additional effect which makes DLLs more wasteful: 2276 DLLs are loaded in the shared memory region, which is a scarse resource 2277 given the 512M barrier of the "standard" OS/2 virtual memory. The code of 2278 F<.EXE> files is also shared by all the processes which use the particular 2279 F<.EXE>, but they are "shared in the private address space of the process"; 2280 this is possible because the address at which different sections 2281 of the F<.EXE> file are loaded is decided at compile-time, thus all the 2282 processes have these sections loaded at same addresses, and no fixup 2283 of internal links inside the F<.EXE> is needed. 2284 2285 Since DLLs may be loaded at run time, to have the same mechanism for DLLs 2286 one needs to have the address range of I<any of the loaded> DLLs in the 2287 system to be available I<in all the processes> which did not load a particular 2288 DLL yet. This is why the DLLs are mapped to the shared memory region. 2289 2290 =head2 Why chimera build? 2291 2292 Current EMX environment does not allow DLLs compiled using Unixish 2293 C<a.out> format to export symbols for data (or at least some types of 2294 data). This forces C<omf>-style compile of F<perl.dll>. 2295 2296 Current EMX environment does not allow F<.EXE> files compiled in 2297 C<omf> format to fork(). fork() is needed for exactly three Perl 2298 operations: 2299 2300 =over 4 2301 2302 =item * 2303 2304 explicit fork() in the script, 2305 2306 =item * 2307 2308 C<open FH, "|-"> 2309 2310 =item * 2311 2312 C<open FH, "-|">, in other words, opening pipes to itself. 2313 2314 =back 2315 2316 While these operations are not questions of life and death, they are 2317 needed for a lot of 2318 useful scripts. This forces C<a.out>-style compile of 2319 F<perl.exe>. 2320 2321 2322 =head1 ENVIRONMENT 2323 2324 Here we list environment variables with are either OS/2- and DOS- and 2325 Win*-specific, or are more important under OS/2 than under other OSes. 2326 2327 =head2 C<PERLLIB_PREFIX> 2328 2329 Specific for EMX port. Should have the form 2330 2331 path1;path2 2332 2333 or 2334 2335 path1 path2 2336 2337 If the beginning of some prebuilt path matches F<path1>, it is 2338 substituted with F<path2>. 2339 2340 Should be used if the perl library is moved from the default 2341 location in preference to C<PERL(5)LIB>, since this would not leave wrong 2342 entries in @INC. For example, if the compiled version of perl looks for @INC 2343 in F<f:/perllib/lib>, and you want to install the library in 2344 F<h:/opt/gnu>, do 2345 2346 set PERLLIB_PREFIX=f:/perllib/lib;h:/opt/gnu 2347 2348 This will cause Perl with the prebuilt @INC of 2349 2350 f:/perllib/lib/5.00553/os2 2351 f:/perllib/lib/5.00553 2352 f:/perllib/lib/site_perl/5.00553/os2 2353 f:/perllib/lib/site_perl/5.00553 2354 . 2355 2356 to use the following @INC: 2357 2358 h:/opt/gnu/5.00553/os2 2359 h:/opt/gnu/5.00553 2360 h:/opt/gnu/site_perl/5.00553/os2 2361 h:/opt/gnu/site_perl/5.00553 2362 . 2363 2364 =head2 C<PERL_BADLANG> 2365 2366 If 0, perl ignores setlocale() failing. May be useful with some 2367 strange I<locale>s. 2368 2369 =head2 C<PERL_BADFREE> 2370 2371 If 0, perl would not warn of in case of unwarranted free(). With older 2372 perls this might be 2373 useful in conjunction with the module DB_File, which was buggy when 2374 dynamically linked and OMF-built. 2375 2376 Should not be set with newer Perls, since this may hide some I<real> problems. 2377 2378 =head2 C<PERL_SH_DIR> 2379 2380 Specific for EMX port. Gives the directory part of the location for 2381 F<sh.exe>. 2382 2383 =head2 C<USE_PERL_FLOCK> 2384 2385 Specific for EMX port. Since L<flock(3)> is present in EMX, but is not 2386 functional, it is emulated by perl. To disable the emulations, set 2387 environment variable C<USE_PERL_FLOCK=0>. 2388 2389 =head2 C<TMP> or C<TEMP> 2390 2391 Specific for EMX port. Used as storage place for temporary files. 2392 2393 =head1 Evolution 2394 2395 Here we list major changes which could make you by surprise. 2396 2397 =head2 Text-mode filehandles 2398 2399 Starting from version 5.8, Perl uses a builtin translation layer for 2400 text-mode files. This replaces the efficient well-tested EMX layer by 2401 some code which should be best characterized as a "quick hack". 2402 2403 In addition to possible bugs and an inability to follow changes to the 2404 translation policy with off/on switches of TERMIO translation, this 2405 introduces a serious incompatible change: before sysread() on 2406 text-mode filehandles would go through the translation layer, now it 2407 would not. 2408 2409 =head2 Priorities 2410 2411 C<setpriority> and C<getpriority> are not compatible with earlier 2412 ports by Andreas Kaiser. See C<"setpriority, getpriority">. 2413 2414 =head2 DLL name mangling: pre 5.6.2 2415 2416 With the release 5.003_01 the dynamically loadable libraries 2417 should be rebuilt when a different version of Perl is compiled. In particular, 2418 DLLs (including F<perl.dll>) are now created with the names 2419 which contain a checksum, thus allowing workaround for OS/2 scheme of 2420 caching DLLs. 2421 2422 It may be possible to code a simple workaround which would 2423 2424 =over 2425 2426 =item * 2427 2428 find the old DLLs looking through the old @INC; 2429 2430 =item * 2431 2432 mangle the names according to the scheme of new perl and copy the DLLs to 2433 these names; 2434 2435 =item * 2436 2437 edit the internal C<LX> tables of DLL to reflect the change of the name 2438 (probably not needed for Perl extension DLLs, since the internally coded names 2439 are not used for "specific" DLLs, they used only for "global" DLLs). 2440 2441 =item * 2442 2443 edit the internal C<IMPORT> tables and change the name of the "old" 2444 F<perl????.dll> to the "new" F<perl????.dll>. 2445 2446 =back 2447 2448 =head2 DLL name mangling: 5.6.2 and beyond 2449 2450 In fact mangling of I<extension> DLLs was done due to misunderstanding 2451 of the OS/2 dynaloading model. OS/2 (effectively) maintains two 2452 different tables of loaded DLL: 2453 2454 =over 2455 2456 =item Global DLLs 2457 2458 those loaded by the base name from C<LIBPATH>; including those 2459 associated at link time; 2460 2461 =item specific DLLs 2462 2463 loaded by the full name. 2464 2465 =back 2466 2467 When resolving a request for a global DLL, the table of already-loaded 2468 specific DLLs is (effectively) ignored; moreover, specific DLLs are 2469 I<always> loaded from the prescribed path. 2470 2471 There is/was a minor twist which makes this scheme fragile: what to do 2472 with DLLs loaded from 2473 2474 =over 2475 2476 =item C<BEGINLIBPATH> and C<ENDLIBPATH> 2477 2478 (which depend on the process) 2479 2480 =item F<.> from C<LIBPATH> 2481 2482 which I<effectively> depends on the process (although C<LIBPATH> is the 2483 same for all the processes). 2484 2485 =back 2486 2487 Unless C<LIBPATHSTRICT> is set to C<T> (and the kernel is after 2488 2000/09/01), such DLLs are considered to be global. When loading a 2489 global DLL it is first looked in the table of already-loaded global 2490 DLLs. Because of this the fact that one executable loaded a DLL from 2491 C<BEGINLIBPATH> and C<ENDLIBPATH>, or F<.> from C<LIBPATH> may affect 2492 I<which> DLL is loaded when I<another> executable requests a DLL with 2493 the same name. I<This> is the reason for version-specific mangling of 2494 the DLL name for perl DLL. 2495 2496 Since the Perl extension DLLs are always loaded with the full path, 2497 there is no need to mangle their names in a version-specific ways: 2498 their directory already reflects the corresponding version of perl, 2499 and @INC takes into account binary compatibility with older version. 2500 Starting from C<5.6.2> the name mangling scheme is fixed to be the 2501 same as for Perl 5.005_53 (same as in a popular binary release). Thus 2502 new Perls will be able to I<resolve the names> of old extension DLLs 2503 if @INC allows finding their directories. 2504 2505 However, this still does not guarantee that these DLL may be loaded. 2506 The reason is the mangling of the name of the I<Perl DLL>. And since 2507 the extension DLLs link with the Perl DLL, extension DLLs for older 2508 versions would load an older Perl DLL, and would most probably 2509 segfault (since the data in this DLL is not properly initialized). 2510 2511 There is a partial workaround (which can be made complete with newer 2512 OS/2 kernels): create a forwarder DLL with the same name as the DLL of 2513 the older version of Perl, which forwards the entry points to the 2514 newer Perl's DLL. Make this DLL accessible on (say) the C<BEGINLIBPATH> of 2515 the new Perl executable. When the new executable accesses old Perl's 2516 extension DLLs, they would request the old Perl's DLL by name, get the 2517 forwarder instead, so effectively will link with the currently running 2518 (new) Perl DLL. 2519 2520 This may break in two ways: 2521 2522 =over 2523 2524 =item * 2525 2526 Old perl executable is started when a new executable is running has 2527 loaded an extension compiled for the old executable (ouph!). In this 2528 case the old executable will get a forwarder DLL instead of the old 2529 perl DLL, so would link with the new perl DLL. While not directly 2530 fatal, it will behave the same as new executable. This beats the whole 2531 purpose of explicitly starting an old executable. 2532 2533 =item * 2534 2535 A new executable loads an extension compiled for the old executable 2536 when an old perl executable is running. In this case the extension 2537 will not pick up the forwarder - with fatal results. 2538 2539 =back 2540 2541 With support for C<LIBPATHSTRICT> this may be circumvented - unless 2542 one of DLLs is started from F<.> from C<LIBPATH> (I do not know 2543 whether C<LIBPATHSTRICT> affects this case). 2544 2545 B<REMARK>. Unless newer kernels allow F<.> in C<BEGINLIBPATH> (older 2546 do not), this mess cannot be completely cleaned. (It turns out that 2547 as of the beginning of 2002, F<.> is not allowed, but F<.\.> is - and 2548 it has the same effect.) 2549 2550 2551 B<REMARK>. C<LIBPATHSTRICT>, C<BEGINLIBPATH> and C<ENDLIBPATH> are 2552 not environment variables, although F<cmd.exe> emulates them on C<SET 2553 ...> lines. From Perl they may be accessed by L<Cwd::extLibpath> and 2554 L<Cwd::extLibpath_set>. 2555 2556 =head2 DLL forwarder generation 2557 2558 Assume that the old DLL is named F<perlE0AC.dll> (as is one for 2559 5.005_53), and the new version is 5.6.1. Create a file 2560 F<perl5shim.def-leader> with 2561 2562 LIBRARY 'perlE0AC' INITINSTANCE TERMINSTANCE 2563 DESCRIPTION '@#perl5-porters@perl.org:5.006001#@ Perl module for 5.00553 -> Perl 5.6.1 forwarder' 2564 CODE LOADONCALL 2565 DATA LOADONCALL NONSHARED MULTIPLE 2566 EXPORTS 2567 2568 modifying the versions/names as needed. Run 2569 2570 perl -wnle "next if 0../EXPORTS/; print qq( \"$1\") if /\"(\w+)\"/" perl5.def >lst 2571 2572 in the Perl build directory (to make the DLL smaller replace perl5.def 2573 with the definition file for the older version of Perl if present). 2574 2575 cat perl5shim.def-leader lst >perl5shim.def 2576 gcc -Zomf -Zdll -o perlE0AC.dll perl5shim.def -s -llibperl 2577 2578 (ignore multiple C<warning L4085>). 2579 2580 =head2 Threading 2581 2582 As of release 5.003_01 perl is linked to multithreaded C RTL 2583 DLL. If perl itself is not compiled multithread-enabled, so will not be perl's 2584 malloc(). However, extensions may use multiple thread on their own 2585 risk. 2586 2587 This was needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box, and 2588 link with DLLs for other useful libraries, which typically are compiled 2589 with C<-Zmt -Zcrtdll>. 2590 2591 =head2 Calls to external programs 2592 2593 Due to a popular demand the perl external program calling has been 2594 changed wrt Andreas Kaiser's port. I<If> perl needs to call an 2595 external program I<via shell>, the F<f:/bin/sh.exe> will be called, or 2596 whatever is the override, see L<"PERL_SH_DIR">. 2597 2598 Thus means that you need to get some copy of a F<sh.exe> as well (I 2599 use one from pdksh). The path F<F:/bin> above is set up automatically during 2600 the build to a correct value on the builder machine, but is 2601 overridable at runtime, 2602 2603 B<Reasons:> a consensus on C<perl5-porters> was that perl should use 2604 one non-overridable shell per platform. The obvious choices for OS/2 2605 are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible 2606 with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. This assures almost 2607 100% compatibility with the scripts coming from *nix. As an added benefit 2608 this works as well under DOS if you use DOS-enabled port of pdksh 2609 (see L<"Prerequisites">). 2610 2611 B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs 2612 via fork()/exec(), and there is I<no> functioning exec() on 2613 OS/2. exec() is emulated by EMX by an asynchronous call while the caller 2614 waits for child completion (to pretend that the C<pid> did not change). This 2615 means that 1 I<extra> copy of F<sh.exe> is made active via fork()/exec(), 2616 which may lead to some resources taken from the system (even if we do 2617 not count extra work needed for fork()ing). 2618 2619 Note that this a lesser issue now when we do not spawn F<sh.exe> 2620 unless needed (metachars found). 2621 2622 One can always start F<cmd.exe> explicitly via 2623 2624 system 'cmd', '/c', 'mycmd', 'arg1', 'arg2', ... 2625 2626 If you need to use F<cmd.exe>, and do not want to hand-edit thousands of your 2627 scripts, the long-term solution proposed on p5-p is to have a directive 2628 2629 use OS2::Cmd; 2630 2631 which will override system(), exec(), C<``>, and 2632 C<open(,'...|')>. With current perl you may override only system(), 2633 readpipe() - the explicit version of C<``>, and maybe exec(). The code 2634 will substitute the one-argument call to system() by 2635 C<CORE::system('cmd.exe', '/c', shift)>. 2636 2637 If you have some working code for C<OS2::Cmd>, please send it to me, 2638 I will include it into distribution. I have no need for such a module, so 2639 cannot test it. 2640 2641 For the details of the current situation with calling external programs, 2642 see L<Starting OS/2 (and DOS) programs under Perl>. Set us mention a couple 2643 of features: 2644 2645 =over 4 2646 2647 =item * 2648 2649 External scripts may be called by their basename. Perl will try the same 2650 extensions as when processing B<-S> command-line switch. 2651 2652 =item * 2653 2654 External scripts starting with C<#!> or C<extproc > will be executed directly, 2655 without calling the shell, by calling the program specified on the rest of 2656 the first line. 2657 2658 =back 2659 2660 =head2 Memory allocation 2661 2662 Perl uses its own malloc() under OS/2 - interpreters are usually malloc-bound 2663 for speed, but perl is not, since its malloc is lightning-fast. 2664 Perl-memory-usage-tuned benchmarks show that Perl's malloc is 5 times quicker 2665 than EMX one. I do not have convincing data about memory footprint, but 2666 a (pretty random) benchmark showed that Perl's one is 5% better. 2667 2668 Combination of perl's malloc() and rigid DLL name resolution creates 2669 a special problem with library functions which expect their return value to 2670 be free()d by system's free(). To facilitate extensions which need to call 2671 such functions, system memory-allocation functions are still available with 2672 the prefix C<emx_> added. (Currently only DLL perl has this, it should 2673 propagate to F<perl_.exe> shortly.) 2674 2675 =head2 Threads 2676 2677 One can build perl with thread support enabled by providing C<-D usethreads> 2678 option to F<Configure>. Currently OS/2 support of threads is very 2679 preliminary. 2680 2681 Most notable problems: 2682 2683 =over 4 2684 2685 =item C<COND_WAIT> 2686 2687 may have a race condition (but probably does not due to edge-triggered 2688 nature of OS/2 Event semaphores). (Needs a reimplementation (in terms of chaining 2689 waiting threads, with the linked list stored in per-thread structure?)?) 2690 2691 =item F<os2.c> 2692 2693 has a couple of static variables used in OS/2-specific functions. (Need to be 2694 moved to per-thread structure, or serialized?) 2695 2696 =back 2697 2698 Note that these problems should not discourage experimenting, since they 2699 have a low probability of affecting small programs. 2700 2701 =head1 BUGS 2702 2703 This description is not updated often (since 5.6.1?), see F<./os2/Changes> 2704 (L<perlos2delta>) for more info. 2705 2706 =cut 2707 2708 OS/2 extensions 2709 ~~~~~~~~~~~~~~~ 2710 I include 3 extensions by Andreas Kaiser, OS2::REXX, OS2::UPM, and OS2::FTP, 2711 into my ftp directory, mirrored on CPAN. I made 2712 some minor changes needed to compile them by standard tools. I cannot 2713 test UPM and FTP, so I will appreciate your feedback. Other extensions 2714 there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI 2715 files - and maybe some other extensions at the time you read it. 2716 2717 Note that OS2 perl defines 2 pseudo-extension functions 2718 OS2::Copy::copy and DynaLoader::mod2fname (many more now, see 2719 L<Prebuilt methods>). 2720 2721 The -R switch of older perl is deprecated. If you need to call a REXX code 2722 which needs access to variables, include the call into a REXX compartment 2723 created by 2724 REXX_call {...block...}; 2725 2726 Two new functions are supported by REXX code, 2727 REXX_eval 'string'; 2728 REXX_eval_with 'string', REXX_function_name => \&perl_sub_reference; 2729 2730 If you have some other extensions you want to share, send the code to 2731 me. At least two are available: tied access to EA's, and tied access 2732 to system databases. 2733 2734 =head1 AUTHOR 2735 2736 Ilya Zakharevich, cpan@ilyaz.org 2737 2738 =head1 SEE ALSO 2739 2740 perl(1). 2741 2742 =cut 2743
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