README.os2

Message-ID: <20020628133239.A26455@math.ohio-state.edu>

p4raw-id: //depot/perl@17379

1 files changed, 384 insertions, 156 deletions

diff --git a/README.os2 b/README.os2
index 8cc0ec7d40..e23aad9805 100644
--- a/README.os2
+++ b/README.os2
@@ -29,9 +29,9 @@ A copy of a Win* viewer is contained in the "Just add OS/2 Warp" package
 
 in F<?:\JUST_ADD\view.exe>. This gives one an access to EMX's 
 F<.INF> docs as well (text form is available in F</emx/doc> in 
-EMX's distribution).
+EMX's distribution).  There is also a different viewer named xview.
 
-Note that if you have F<lynx.exe> installed, you can follow WWW links
+Note that if you have F<lynx.exe> or F<netscape.exe> installed, you can follow WWW links
 from this document in F<.INF> format. If you have EMX docs installed 
 correctly, you can follow library links (you need to have C<view emxbook>
 working by setting C<EMXBOOK> environment variable as it is described
@@ -39,88 +39,99 @@ in EMX docs).
 
 =cut
 
-Contents
+Contents (This may be a little bit obsolete)
  
  perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT. 
 
-      NAME 
-      SYNOPSIS 
-      DESCRIPTION 
-         -  Target 
-         -  Other OSes 
-         -  Prerequisites 
-         -  Starting Perl programs under OS/2 (and DOS and...)
-         -  Starting OS/2 (and DOS) programs under Perl 
-      Frequently asked questions 
-         -  I cannot run external programs 
-         -  I cannot embed perl into my program, or use perl.dll from my program. 
-         -  `` and pipe-open do not work under DOS. 
-         -  Cannot start find.exe "pattern" file
-      INSTALLATION 
-         -  Automatic binary installation 
-         -  Manual binary installation 
-         -  Warning 
-      Accessing documentation 
-         -  OS/2 .INF file 
-         -  Plain text 
-         -  Manpages 
-         -  HTML 
-         -  GNU info files 
-         -  .PDF files 
-         -  LaTeX docs 
-      BUILD 
-         -  Prerequisites 
-         -  Getting perl source 
-         -  Application of the patches 
-         -  Hand-editing 
-         -  Making 
-         -  Testing 
-         -  Installing the built perl 
-         -  a.out-style build 
-      Build FAQ 
-         -  Some / became \ in pdksh. 
-         -  'errno' - unresolved external 
-         -  Problems with tr 
-         -  Some problem (forget which ;-) 
-         -  Library ... not found 
-         -  Segfault in make 
-      Specific (mis)features of EMX port 
-         -  setpriority, getpriority 
-         -  system() 
-         -  extproc on the first line
-         -  Additional modules: 
-         -  Prebuilt methods: 
-         -  Misfeatures 
-         -  Modifications 
-      Perl flavors 
-         -  perl.exe 
-         -  perl_.exe 
-         -  perl__.exe 
-         -  perl___.exe 
-         -  Why strange names? 
-         -  Why dynamic linking? 
-         -  Why chimera build? 
-      ENVIRONMENT 
-         -  PERLLIB_PREFIX 
-         -  PERL_BADLANG 
-         -  PERL_BADFREE 
-         -  PERL_SH_DIR 
-         -  TMP or TEMP 
-      Evolution 
-         -  Priorities 
-         -  DLL name mangling 
-         -  Threading 
-         -  Calls to external programs 
-         -  Memory allocation 
-         -  Threads
-      AUTHOR 
-      SEE ALSO 
+      NAME
+      SYNOPSIS
+      DESCRIPTION
+	 -  Target
+	 -  Other OSes
+	 -  Prerequisites
+	 -  Starting Perl programs under OS/2 (and DOS and...)
+	 -  Starting OS/2 (and DOS) programs under Perl
+      Frequently asked questions
+	 -  "It does not work"
+	 -  I cannot run external programs
+	 -  I cannot embed perl into my program, or use perl.dll from my
+	 -  `` and pipe-open do not work under DOS.
+	 -  Cannot start find.exe "pattern" file
+      INSTALLATION
+	 -  Automatic binary installation
+	 -  Manual binary installation
+	 -  Warning
+      Accessing documentation
+	 -  OS/2 .INF file
+	 -  Plain text
+	 -  Manpages
+	 -  HTML
+	 -  GNU info files
+	 -  PDF files
+	 -  LaTeX docs
+      BUILD
+	 -  The short story
+	 -  Prerequisites
+	 -  Getting perl source
+	 -  Application of the patches
+	 -  Hand-editing
+	 -  Making
+	 -  Testing
+	 -  Installing the built perl
+	 -  a.out-style build
+      Build FAQ
+	 -  Some / became \ in pdksh.
+	 -  'errno' - unresolved external
+	 -  Problems with tr or sed
+	 -  Some problem (forget which ;-)
+	 -  Library ... not found
+	 -  Segfault in make
+	 -  op/sprintf test failure
+      Specific (mis)features of OS/2 port
+	 -  setpriority, getpriority
+	 -  system()
+	 -  extproc on the first line
+	 -  Additional modules:
+	 -  Prebuilt methods:
+	 -  Prebuilt variables:
+	 -  Misfeatures
+	 -  Modifications
+	 -  Identifying DLLs
+	 -  Centralized management of resources
+      Perl flavors
+	 -  perl.exe
+	 -  perl_.exe
+	 -  perl__.exe
+	 -  perl___.exe
+	 -  Why strange names?
+	 -  Why dynamic linking?
+	 -  Why chimera build?
+      ENVIRONMENT
+	 -  PERLLIB_PREFIX
+	 -  PERL_BADLANG
+	 -  PERL_BADFREE
+	 -  PERL_SH_DIR
+	 -  USE_PERL_FLOCK
+	 -  TMP or TEMP
+      Evolution
+	 -  Text-mode filehandles
+	 -  Priorities
+	 -  DLL name mangling: pre 5.6.2
+	 -  DLL name mangling: 5.6.2 and beyond
+	 -  DLL forwarder generation
+	 -  Threading
+	 -  Calls to external programs
+	 -  Memory allocation
+	 -  Threads
+      BUGS
+      AUTHOR
+      SEE ALSO
 
 =head1 DESCRIPTION
 
 =head2 Target
 
-The target is to make OS/2 the best supported platform for
+The target is to make OS/2 one of the best supported platform for
 using/building/developing Perl and I<Perl applications>, as well as
 make Perl the best language to use under OS/2. The secondary target is
 to try to make this work under DOS and Win* as well (but not B<too> hard).
@@ -131,10 +142,12 @@ The current state is quite close to this target. Known limitations:
 
 =item *
 
-Some *nix programs use fork() a lot; with the mostly useful flavors of perl
-for OS/2 (there are several built simultaneously) this is supported;
-some flavors do not.  Using fork() after I<use>ing dynamically loading
-extensions would not work with very old versions of EMX.
+Some *nix programs use fork() a lot; with the mostly useful flavors of
+perl for OS/2 (there are several built simultaneously) this is
+supported; but some flavors do not support this (e.g., when Perl is
+called from inside REXX).  Using fork() after
+I<use>ing dynamically loading extensions would not work with I<very> old
+versions of EMX.
 
 =item *
 
@@ -149,10 +162,13 @@ Using F<perl__.exe> avoids such a degradation.
 =item *
 
 There is no simple way to access WPS objects. The only way I know
-is via C<OS2::REXX> extension (see L<OS2::REXX>), and we do not have access to
+is via C<OS2::REXX> and C<SOM> extensions (see L<OS2::REXX>, L<Som>).
+However, we do not have access to
 convenience methods of Object-REXX. (Is it possible at all? I know
 of no Object-REXX API.)  The C<SOM> extension (currently in alpha-text)
-may eventually remove this shortcoming.
+may eventually remove this shortcoming; however, due to the fact that
+DII is not supported by the C<SOM> module, using C<SOM> is not as
+convenient as one would like it.
 
 =back
 
@@ -184,7 +200,8 @@ external support by binding F<emx.exe>/F<rsx.exe> to it, see L<emxbind>. Note
 that under DOS for best results one should use RSX runtime, which
 has much more functions working (like C<fork>, C<popen> and so on). In
 fact RSX is required if there is no VCPI present. Note the
-RSX requires DPMI.
+RSX requires DPMI.  Many implementations of DPMI are known to be very
+buggy, beware!
 
 Only the latest runtime is supported, currently C<0.9d fix 03>. Perl may run
 under earlier versions of EMX, but this is not tested.
@@ -197,7 +214,7 @@ One can get different parts of EMX from, say
 
 The runtime component should have the name F<emxrt.zip>.
 
-B<NOTE>. It is enough to have F<emx.exe>/F<rsx.exe> on your path. One
+B<NOTE>. When using F<emx.exe>/F<rsx.exe>, it is enough to have them on your path. One
 does not need to specify them explicitly (though this
 
   emx perl_.exe -de 0
@@ -226,14 +243,15 @@ Contact the author on C<rainer@mathematik.uni-bielefeld.de>.
 
 The latest F<sh.exe> with DOS hooks is available in
 
-  ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/
+  http://www.ilyaz.org/software/os2/
 
 as F<sh_dos.zip> or under similar names starting with C<sh>, C<pdksh> etc.
 
 =item HPFS
 
-Perl does not care about file systems, but to install the whole perl
-library intact one needs a file system which supports long file names.
+Perl does not care about file systems, but the perl library contains
+many files with long names, so to install it intact one needs a file
+system which supports long file names.
 
 Note that if you do not plan to build the perl itself, it may be
 possible to fool EMX to truncate file names. This is not supported,
@@ -250,7 +268,7 @@ or in configurable location (see L<"PERL_SH_DIR">).
 For best results use EMX pdksh. The standard binary (5.2.14 or later) runs
 under DOS (with L<RSX>) as well, see
 
-  ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/
+  http://www.ilyaz.org/software/os2/
 
 =back
 
@@ -301,7 +319,7 @@ There are also endless possibilities to use I<executable extensions> of
 *nixish shell (like F<sh.exe> supplied in the binary distribution),
 you need to follow the syntax specified in L<perlrun/"Switches">.
 
-Note that B<-S> switch enables a search with additional extensions 
+Note that B<-S> switch supports scripts with additional extensions 
 F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well.
 
 =head2 Starting OS/2 (and DOS) programs under Perl
@@ -348,11 +366,12 @@ without "magic" line, and C<$ENV{EXECSHELL}> is set to shell;
 =item 6
 
 If the executable called by system()/exec()/pipe-open()/C<``> is not
-found;
+found (is not this remark obsolete?);
 
 =item 7
 
-For globbing (see L<perlfunc/glob>, L<perlop/"I/O Operators">).
+For globbing (see L<perlfunc/glob>, L<perlop/"I/O Operators">)
+(obsolete? Perl uses builtin globbing nowadays...).
 
 =back
 
@@ -362,7 +381,8 @@ backslashes in the command name are not considered as shell metacharacters.
 Perl starts scripts which begin with cookies
 C<extproc> or C<#!> directly, without an intervention of shell.  Perl uses the
 same algorithm to find the executable as F<pdksh>: if the path
-on C<#!> line does not work, and contains C</>, then the executable
+on C<#!> line does not work, and contains C</>, then the directory
+part of the executable is ignored, and the executable
 is searched in F<.> and on C<PATH>.  To find arguments for these scripts
 Perl uses a different algorithm than F<pdksh>: up to 3 arguments are 
 recognized, and trailing whitespace is stripped.
@@ -374,7 +394,7 @@ script is given as the first argument to this command, if not set, then
 C<$ENV{COMSPEC} /c> is used (or a hardwired guess if C<$ENV{COMSPEC}> is
 not set).
 
-If starting scripts directly, Perl will use exactly the same algorithm as for 
+When starting scripts directly, Perl uses exactly the same algorithm as for 
 the search of script given by B<-S> command-line option: it will look in
 the current directory, then on components of C<$ENV{PATH}> using the 
 following order of appended extensions: no extension, F<.cmd>, F<.btm>, 
@@ -382,17 +402,20 @@ F<.bat>, F<.pl>.
 
 Note that Perl will start to look for scripts only if OS/2 cannot start the
 specified application, thus C<system 'blah'> will not look for a script if 
-there is an executable file F<blah.exe> I<anywhere> on C<PATH>.  
+there is an executable file F<blah.exe> I<anywhere> on C<PATH>.  In
+other words, C<PATH> is essentially searched twice: once by the OS for
+an executable, then by Perl for scripts.
 
 Note also that executable files on OS/2 can have an arbitrary extension, 
 but F<.exe> will be automatically appended if no dot is present in the name.  
 The workaround is as simple as that:  since F<blah.> and F<blah> denote the 
-same file, to start an executable residing in file F<n:/bin/blah> (no 
+same file (at list on FAT and HPFS file systems), to start an executable residing in file F<n:/bin/blah> (no 
 extension) give an argument C<n:/bin/blah.> (dot appended) to system().
 
-Perl will correctly start PM programs from VIO (=text-mode) Perl process;
+Perl will start PM programs from VIO (=text-mode) Perl process in a
+separate PM session;
 the opposite is not true: when you start a non-PM program from a PM
-Perl process, it would not run it in a separate session.  If a separate
+Perl process, Perl would not run it in a separate session.  If a separate
 session is desired, either ensure
 that shell will be used, as in C<system 'cmd /c myprog'>, or start it using
 optional arguments to system() documented in C<OS2::Process> module.  This
@@ -432,12 +455,22 @@ program.
 
 =item Is your program EMX-compiled with C<-Zmt -Zcrtdll>?
 
-If not, you need to build a stand-alone DLL for perl. Contact me, I
-did it once. Sockets would not work, as a lot of other stuff.
+Well, nowadays Perl DLL should be usable from a differently compiled
+program too...  If you can run Perl code from REXX scripts (see
+L<OS2::REXX>), then there are some other aspect of interaction which
+are overlooked by the current hackish code to support
+differently-compiled principal programs.
+
+If everything else fails, you need to build a stand-alone DLL for
+perl. Contact me, I did it once. Sockets would not work, as a lot of
+other stuff.
 
 =item Did you use L<ExtUtils::Embed>?
 
-I had reports it does not work. Somebody would need to fix it.
+Some time ago I had reports it does not work.  Nowadays it is checked
+in the Perl test suite, so grep F<./t> subdirectory of the build tree
+(as well as F<*.t> files in the F<./lib> subdirectory) to find how it
+should be done "correctly".
 
 =back
 
@@ -454,6 +487,18 @@ DPMI is required for RSX.
 
 =head2 Cannot start C<find.exe "pattern" file>
 
+The whole idea of the "standard C API to start applications" is that
+the forms C<foo> and C<"foo"> of program arguments are completely
+interchangable.  F<find> breaks this paradigm;
+
+  find "pattern" file
+  find pattern file
+
+are not equivalent; F<find> cannot be started directly using the above
+API.  One needs a way to surround the doublequotes in some other
+quoting construction, necessarily having an extra non-Unixish shell in
+between.
+
 Use one of
 
   system 'cmd', '/c', 'find "pattern" file';
@@ -461,12 +506,7 @@ Use one of
 
 This would start F<find.exe> via F<cmd.exe> via C<sh.exe> via
 C<perl.exe>, but this is a price to pay if you want to use
-non-conforming program. In fact F<find.exe> cannot be started at all
-using C library API only. Otherwise the following command-lines would be
-equivalent:
-
-  find "pattern" file
-  find pattern file
+non-conforming program.
 
 =head1 INSTALLATION
 
@@ -483,8 +523,11 @@ you may need to reboot in between. Check EMX runtime by running
 
 	emxrev
 
-A folder is created on your desktop which contains some useful
-objects.
+Binary installer also creates a folder on your desktop with some useful
+objects.  If you need to change some aspects of the work of the binary
+installer, feel free to edit the file F<Perl.pkg>.  This may be useful
+e.g., if you need to run the installer many times and do not want to
+make many interactive changes in the GUI.
 
 B<Things not taken care of by automatic binary installation:>
 
@@ -508,7 +551,9 @@ perl library, find it out by
 
 While most important values in this file I<are> updated by the binary
 installer, some of them may need to be hand-edited. I know no such
-data, please keep me informed if you find one.
+data, please keep me informed if you find one.  Moreover, manual
+changes to the installed version may need to be accompanied by an edit
+of this file.
 
 =back
 
@@ -528,11 +573,18 @@ Note that the extraction with the stored paths is still necessary
 need to know where to extract the files. You need also to manually
 change entries in F<Config.sys> to reflect where did you put the
 files. Note that if you have some primitive unzipper (like
-pkunzip), you may get a lot of warnings/errors during
+C<pkunzip>), you may get a lot of warnings/errors during
 unzipping. Upgrade to C<(w)unzip>.
 
 Below is the sample of what to do to reproduce the configuration on my
-machine:
+machine.  In F<VIEW.EXE> you can press C<Ctrl-Insert> now, and
+cut-and-paste from the resulting file - created in the directory you
+started F<VIEW.EXE> from.
+
+For each component, we mention environment variables related to each
+installation directory.  Either choose directories to match your
+values of the variables, or create/append-to variables to take into
+account the directories.
 
 =over 3
 
@@ -577,6 +629,9 @@ directory and subdirectory F<./os2> in C<PERLLIB> or C<PERL5LIB>
 variable. Do not use C<PERL5LIB> unless you have it set already. See
 L<perl/"ENVIRONMENT">.
 
+B<[Check whether this extraction directory is still applicable with
+the new directory structure layout!]>
+
 =item Tools to compile Perl modules
 
   unzip perl_blb.zip -d f:/perllib/lib
@@ -588,7 +643,7 @@ Same remark as for F<perl_ste.zip>.
   unzip perl_man.zip -d f:/perllib/man
 
 This directory should better be on C<MANPATH>. You need to have a
-working man to access these files.
+working F<man> to access these files.
 
 =item Manpages for Perl modules
 
@@ -604,7 +659,8 @@ working man to access these files.
 This is used by the C<perldoc> program (see L<perldoc>), and may be used to
 generate HTML documentation usable by WWW browsers, and
 documentation in zillions of other formats: C<info>, C<LaTeX>,
-C<Acrobat>, C<FrameMaker> and so on.
+C<Acrobat>, C<FrameMaker> and so on.  [Use programs such as
+F<pod2latex> etc.]
 
 =item Perl manual in F<.INF> format
 
@@ -623,8 +679,7 @@ metacharacters>. It is also used instead of explicit F</bin/sh>.
 Set C<PERL_SH_DIR> (see L<"PERL_SH_DIR">) if you move F<sh.exe> from
 the above location.
 
-B<Note.> It may be possible to use some other sh-compatible shell
-(file globbing - if done via shell - may break).
+B<Note.> It may be possible to use some other sh-compatible shell (untested).
 
 =back
 
@@ -642,7 +697,7 @@ currently start with C<f:/>).
 
 The automatic and manual perl installation leave precompiled paths
 inside perl executables. While these paths are overwriteable (see
-L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), one may get better results by
+L<"PERLLIB_PREFIX">, L<"PERL_SH_DIR">), some people may prefer
 binary editing of paths inside the executables/DLLs.
 
 =head1 Accessing documentation
@@ -689,7 +744,7 @@ Alternately, try running pod2text on F<.pod> files.
 
 =head2 Manpages
 
-If you have man installed on your system, and you installed perl
+If you have F<man> installed on your system, and you installed perl
 manpages, use something like this:
 
 	man perlfunc
@@ -730,12 +785,12 @@ Alternatively you may be able to get these docs prebuilt from CPAN.
 =head2 GNU C<info> files
 
 Users of Emacs would appreciate it very much, especially with
-C<CPerl> mode loaded. You need to get latest C<pod2info> from C<CPAN>,
-or, alternately, prebuilt info pages.
+C<CPerl> mode loaded. You need to get latest C<pod2texi> from C<CPAN>,
+or, alternately, the prebuilt info pages.
 
 =head2 F<PDF> files
 
-for C<Acrobat> are available on CPAN (for slightly old version of
+for C<Acrobat> are available on CPAN (may be for slightly older version of
 perl).
 
 =head2 C<LaTeX> docs
@@ -745,7 +800,7 @@ can be constructed using C<pod2latex>.
 =head1 BUILD
 
 Here we discuss how to build Perl under OS/2. There is an alternative
-(but maybe older) view on http://www.shadow.net/~troc/os2perl.html
+(but maybe older) view on L<http://www.shadow.net/~troc/os2perl.html>.
 
 =head2 The short story
 
@@ -762,11 +817,16 @@ source distribution.  Untar it, change to the extract directory, and
   make aout_install
 
 This puts the executables in f:/perllib/bin.  Manually move them to the
-C<PATH>, manually move the built F<perl*.dll> to C<LIBPATH> (here F<*> is
-a not-very-meaningful hex checksum), and run
+C<PATH>, manually move the built F<perl*.dll> to C<LIBPATH> (here for
+Perl DLL F<*> is a not-very-meaningful hex checksum), and run
 
   make installcmd INSTALLCMDDIR=d:/ir/on/path
 
+Assuming that the C<man>-files were put on an appropriate location,
+this completes the installation of minimal Perl system.  (The binary
+distribution contains also a lot of additional modules, and the
+documentation in INF format.)
+
 What follows is a detailed guide through these steps.
 
 =head2 Prerequisites
@@ -784,7 +844,7 @@ check use
 Check that you have B<BSD> libraries and headers installed, and - 
 optionally - Berkeley DB headers and libraries, and crypt.
 
-Possible locations to get this from are
+Possible locations to get the files:
 
   ftp://hobbes.nmsu.edu/os2/unix/
   ftp://ftp.cdrom.com/pub/os2/unix/
@@ -793,12 +853,19 @@ Possible locations to get this from are
 
 It is reported that the following archives contain enough utils to
 build perl: F<gnufutil.zip>, F<gnusutil.zip>, F<gnututil.zip>, F<gnused.zip>,
-F<gnupatch.zip>, F<gnuawk.zip>, F<gnumake.zip>, F<bsddev.zip> and
+F<gnupatch.zip>, F<gnuawk.zip>, F<gnumake.zip>, F<gnugrep.zip>, F<bsddev.zip> and
 F<ksh527rt.zip> (or a later version).  Note that all these utilities are
 known to be available from LEO:
 
   ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu
 
+Note also that the F<db.lib> and F<db.a> from the EMX distribution
+are not suitable for multi-threaded compile (even single-threaded
+flavor of Perl uses multi-threaded C RTL, for
+compatibility with XFree86-OS/2). Get a corrected one from
+
+  http://www.ilyaz.org/software/os2/db_mt.zip
+
 If you have I<exactly the same version of Perl> installed already,
 make sure that no copies or perl are currently running.  Later steps
 of the build may fail since an older version of F<perl.dll> loaded into
@@ -808,9 +875,11 @@ Also make sure that you have F</tmp> directory on the current drive,
 and F<.> directory in your C<LIBPATH>. One may try to correct the
 latter condition by
 
-  set BEGINLIBPATH .
+  set BEGINLIBPATH .\.
 
-if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
+if you use something like F<CMD.EXE> or latest versions of
+F<4os2.exe>.  (Setting BEGINLIBPATH to just C<.> is ignored by the
+OS/2 kernel.)
 
 Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
 script in F</emx/lib> directory.
@@ -860,14 +929,11 @@ You need to apply the patches in F<./os2/diff.*> like this:
   gnupatch -p0 < os2\diff.configure
 
 You may also need to apply the patches supplied with the binary
-distribution of perl.
-
-Note also that the F<db.lib> and F<db.a> from the EMX distribution
-are not suitable for multi-threaded compile (even single-threaded
-flavor of Perl uses multi-threaded C RTL, for
-compatibility with XFree86-OS/2). Get a corrected one from
-
-  ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
+distribution of perl.  It also makes sense to look on the
+perl5-porters mailing list for the latest OS/2-related patches (see
+L<http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/>).  Such
+patches usually contain strings C</os2/> and C<patch>, so it makes
+sense looking for these strings.
 
 =head2 Hand-editing
 
@@ -902,7 +968,10 @@ Now run
 
   make test
 
-All tests should succeed (with some of them skipped).
+All tests should succeed (with some of them skipped).  If you have the
+same version of Perl installed, it is crucial that you have C<.> early
+in your LIBPATH (or in BEGINLIBPATH), otherwise your tests will most
+probably test the wrong version of Perl.
 
 Some tests may generate extra messages similar to
 
@@ -974,7 +1043,7 @@ provides only 2sec time granularity (for compatibility with FAT?).
 
 =head2 Installing the built perl
 
-If you haven't yet moved perl.dll onto LIBPATH, do it now.
+If you haven't yet moved C<perl*.dll> onto LIBPATH, do it now.
 
 Run
 
@@ -993,6 +1062,12 @@ PATH. You need to put F<.EXE>-utilities on path manually. They are
 installed in C<$prefix/bin>, here C<$prefix> is what you gave to
 F<Configure>, see L<Making>.
 
+If you use C<man>, either move the installed F<*/man/> directories to
+your C<MANPATH>, or modify C<MANPATH> to match the location.  (One
+could have avoided this by providing a correct C<manpath> option to
+F<./Configure>, or editing F<./config.sh> between configuring and
+making steps.)
+
 =head2 C<a.out>-style build
 
 Proceed as above, but make F<perl_.exe> (see L<"perl_.exe">) by
@@ -1097,8 +1172,8 @@ The only hardwired limit on the recursion depth is implicit: there is a limit
 given to system().  In particular, if no additional arguments are specified
 on the "magic" first lines, then the limit on the depth is 4.
 
-If Perl finds that the found executable is of different type than the
-current session, it will start the new process in a separate session of
+If Perl finds that the found executable is of PM type when the
+current session is not, it will start the new process in a separate session of
 necessary type.  Call via C<OS2::Process> to disable this magic.
 
 B<WARNING>.  Due to the described logic, you need to explicitly
@@ -1122,6 +1197,7 @@ OS/2 databases in the F<.INI> format, and to Extended Attributes.
 
 Two additional extensions by Andreas Kaiser, C<OS2::UPM>, and
 C<OS2::FTP>, are included into C<ILYAZ> directory, mirrored on CPAN.
+Other OS/2-related extensions are available too.
 
 =head2 Prebuilt methods:
 
@@ -1172,14 +1248,14 @@ current dir.
 =item  C<Cwd::extLibpath([type])>
 
 Get current value of extended library search path. If C<type> is
-present and I<true>, works with END_LIBPATH, otherwise with
-C<BEGIN_LIBPATH>. 
+present and positive, works with C<END_LIBPATH>, if negative, works
+with C<LIBPATHSTRICT>, otherwise with C<BEGIN_LIBPATH>. 
 
 =item  C<Cwd::extLibpath_set( path [, type ] )>
 
 Set current value of extended library search path. If C<type> is
-present and I<true>, works with END_LIBPATH, otherwise with
-C<BEGIN_LIBPATH>. 
+present and positive, works with <END_LIBPATH>, if negative, works
+with C<LIBPATHSTRICT>, otherwise with C<BEGIN_LIBPATH>.
 
 =item C<OS2::Error(do_harderror,do_exception)>
 
@@ -1271,6 +1347,12 @@ only.  If no C<new>, disables all the floating point exceptions.
 
 See L<"Misfeatures"> for details.
 
+=item C<OS2::DLLname([how [, \&xsub]])>
+
+Gives the information about the Perl DLL or the DLL containing the C
+function bound to by C<&xsub>.  The meaning of C<how> is: default (2):
+full name; 0: handle; 1: module name.
+
 =back
 
 (Note that some of these may be moved to different libraries -
@@ -1283,7 +1365,8 @@ eventually).
 
 =item $OS2::emx_rev
 
-same as _emx_rev of EMX, a string similar to C<0.9c>.
+numeric value is the same as _emx_rev of EMX, a string value the same
+as _emx_vprt (similar to C<0.9c>).
 
 =item $OS2::emx_env
 
@@ -1293,6 +1376,23 @@ same as _emx_env of EMX, a number similar to 0x8001.
 
 a number C<OS_MAJOR + 0.001 * OS_MINOR>.
 
+=item $OS2::is_aout
+
+true if the Perl library was compiled in AOUT format.
+
+=item $OS2::can_fork
+
+true if the current executable is an AOUT EMX executable, so Perl can
+fork.  Do not use this, use the portable check for
+$Config::Config{dfork}.
+
+=item $OS2::nsyserror
+
+This variable (default is 1) controls whether to enforce the contents
+of $^E to start with C<SYS0003>-like id.  If set to 0, then the string
+value of $^E is what is available from the OS/2 message file.  (Some
+messages in this file have an C<SYS0003>-like id prepended, some not.)
+
 =back
 
 =head2 Misfeatures
@@ -1343,11 +1443,7 @@ Note that C<kill -9> does not work with the current version of EMX.
 
 =item *
 
-Since F<sh.exe> is used for globing (see L<perlfunc/glob>), the bugs
-of F<sh.exe> plague perl as well. 
-
-In particular, uppercase letters do not work in C<[...]>-patterns with
-the current pdksh.
+See L<"Text-mode filehandles">.
 
 =item *
 
@@ -1388,7 +1484,7 @@ some benign Perl programs would get a C<SIGFPE> and would die a horrible death.
 To circumvent this, Perl uses two hacks.  They help against I<one> type of
 damage only: FP flags changed when loading a DLL.
 
-One of the hacks is to disable floating point exceptions on startup (as
+One of the hacks is to disable floating point exceptions on Perl startup (as
 is the default with EMX).  This helps only with compile-time-linked DLLs
 changing the flags before main() had a chance to be called.
 
@@ -1501,6 +1597,116 @@ WM_QUIT, and which did not process the received WM_QUIT message, the
 shutdown will be automatically cancelled.  Do not call C<perl_hmq_GET(1)>
 unless you are going to process messages on an orderly basis.
 
+=item * Treating errors reported by OS/2 API
+
+There are two principal conventions (it is useful to call them C<Dos*>
+and C<Win*> - though this part of the function signature is not always
+determined by the name of the API) of reporting the error conditions
+of OS/2 API.  Most of C<Dos*> APIs report the error code as the result
+of the call (so 0 means success, and there are many types of errors).
+Most of C<Win*> API report success/fail via the result being
+C<TRUE>/C<FALSE>; to find the reason for the failure one should call
+WinGetLastError() API.
+
+Some C<Win*> entry points also overload a "meaningful" return value
+with the error indicator; having a 0 return value indicates an error.
+Yet some other C<Win*> entry points overload things even more, and 0
+return value may mean a successful call returning a valid value 0, as
+well as an error condition; in the case of a 0 return value one should
+call WinGetLastError() API to distinguish a successful call from a
+failing one.
+
+By convention, all the calls to OS/2 API should indicate their
+failures by resetting $^E.  All the Perl-accessible functions which
+call OS/2 API may be broken into two classes: some die()s when an API
+error is encountered, the other report the error via a false return
+value (of course, this does not concern Perl-accessible functions
+which I<expect> a failure of the OS/2 API call, having some workarounds
+coded).
+
+Obviously, in the situation of the last type of the signature of an OS/2
+API, it is must more convenient for the users if the failure is
+indicated by die()ing: one does not need to check $^E to know that
+something went wrong.  If, however, this solution is not desirable by
+some reason, the code in question should reset $^E to 0 before making
+this OS/2 API call, so that the caller of this Perl-accessible
+function has a chance to distinguish a success-but-0-return value from
+a failure.  (One may return undef as an alternative way of reporting
+an error.)
+
+The macros to simplify this type of error propagation are
+
+=over
+
+=item C<CheckOSError(expr)>
+
+Returns true on error, sets $^E.  Expects expr() be a call of
+C<Dos*>-style API.
+
+=item C<CheckWinError(expr)>
+
+Returns true on error, sets $^E.  Expects expr() be a call of
+C<Win*>-style API.
+
+=item C<SaveWinError(expr)>
+
+Returns C<expr>, sets $^E from WinGetLastError() if C<expr> is false.
+
+=item C<SaveCroakWinError(expr,die,name1,name2)>
+
+Returns C<expr>, sets $^E from WinGetLastError() if C<expr> is false,
+and die()s if C<die> and $^E are true.  The message to die is the
+concatenated strings C<name1> and C<name2>, separated by C<": "> from
+the contents of $^E.
+
+=item C<WinError_2_Perl_rc>
+
+Sets C<Perl_rc> to the return value of WinGetLastError().
+
+=item C<FillWinError>
+
+Sets C<Perl_rc> to the return value of WinGetLastError(), and sets $^E
+to the corresponding value.
+
+=item C<FillOSError(rc)>
+
+Sets C<Perl_rc> to C<rc>, and sets $^E to the corresponding value.
+
+=back
+
+=item * Loading DLLs and ordinals in DLLs
+
+Some DLLs are only present in some versions of OS/2, or in some
+configurations of OS/2.  Some exported entry points are present only
+in DLLs shipped with some versions of OS/2.  If these DLLs and entry
+points were linked directly for a Perl executable/DLL or from a Perl
+extensions, this binary would work only with the specified
+versions/setups.  Even if these entry points were not needed, the
+I<load> of the executable (or DLL) would fail.
+
+For example, many newer useful APIs are not present in OS/2 v2; many
+PM-related APIs require DLLs not available on floppy-boot setup.
+
+To make these calls fail I<only when the calls are executed>, one
+should call these API via a dynamic linking API.  There is a subsystem
+in Perl to simplify such type of calls.  A large number of entry
+points available for such linking is provided (see C<entries_ordinals>
+- and also C<PMWIN_entries> - in F<os2ish.h>).  These ordinals can be
+accessed via the APIs:
+
+  CallORD(), DeclFuncByORD(), DeclVoidFuncByORD(),
+  DeclOSFuncByORD(), DeclWinFuncByORD(), AssignFuncPByORD(),
+  DeclWinFuncByORD_CACHE(), DeclWinFuncByORD_CACHE_survive(),
+  DeclWinFuncByORD_CACHE_resetError_survive(),
+  DeclWinFunc_CACHE(), DeclWinFunc_CACHE_resetError(),
+  DeclWinFunc_CACHE_survive(), DeclWinFunc_CACHE_resetError_survive()
+
+See the header files and the C code in the supplied OS/2-related
+modules for the details on usage of these functions.
+
+Some of these functions also combine dynaloading semantic with the
+error-propagation semantic discussed above.
+  
 =back
 
 =head1 Perl flavors
@@ -1564,6 +1770,13 @@ The flavor F<perl__.exe> is required if you want to start your program without
 a VIO window present, but not C<detach>ed (run C<help detach> for more info).
 Very useful for extensions which use PM, like C<Perl/Tk> or C<OpenGL>.
 
+Note also that the differences between PM and VIO executables are only
+in the I<default> behaviour.  One can start I<any> executable in
+I<any> kind of session by using the arguments C</fs>, C</pm> or
+C</win> switches of the command C<start> (of F<CMD.EXE> or a similar
+shell).  Alternatively, one can use the numeric first argument of the
+C<system> Perl function (see L<C<OS2::Process>>).
+
 =head2 F<perl___.exe>
 
 This is an C<omf>-style executable which is dynamically linked to
@@ -1592,8 +1805,8 @@ additional work to make it compile. The reason is the complicated-to-developers
 but very quick and convenient-to-users "hard" dynamic linking used by OS/2.
 
 There are two distinctive features of the dyna-linking model of OS/2:
-all the references to external functions are resolved at the compile time;
-there is no runtime fixup of the DLLs after they are loaded into memory.
+first, all the references to external functions are resolved at the compile time;
+second, there is no runtime fixup of the DLLs after they are loaded into memory.
 The first feature is an enormous advantage over other models: it avoids
 conflicts when several DLLs used by an application export entries with
 the same name.  In such cases "other" models of dyna-linking just choose
@@ -1751,6 +1964,18 @@ Specific for EMX port. Used as storage place for temporary files.
 
 Here we list major changes which could make you by surprise.
 
+=head2 Text-mode filehandles
+
+Starting from version 5.8, Perl uses a builtin translation layer for
+text-mode files.  This replaces the efficient well-tested EMX layer by
+some code which should be best characterized as a "quick hack".
+
+In addition to possible bugs and an inability to follow changes to the
+translation policy with off/on switches of TERMIO translation, this
+introduces a serious incompatible change: before sysread() on
+text-mode filehandles would go through the translation layer, now it
+would not.
+
 =head2 Priorities
 
 C<setpriority> and C<getpriority> are not compatible with earlier
@@ -1888,7 +2113,9 @@ one of DLLs is started from F<.> from C<LIBPATH> (I do not know
 whether C<LIBPATHSTRICT> affects this case).
 
 B<REMARK>.  Unless newer kernels allow F<.> in C<BEGINLIBPATH> (older
-do not), this mess cannot be completely cleaned.
+do not), this mess cannot be completely cleaned.  (It turns out that
+as of the beginning of 2002, F<.> is not allowed, but F<.\.> is - and
+it has the same effect.)
 
 
 B<REMARK>.  C<LIBPATHSTRICT>, C<BEGINLIBPATH> and C<ENDLIBPATH> are
@@ -2027,8 +2254,9 @@ Most notable problems:
 
 =item C<COND_WAIT> 
 
-may have a race condition.  Needs a reimplementation (in terms of chaining
-waiting threads, with the linked list stored in per-thread structure?).
+may have a race condition (but probably does not due to edge-triggered
+nature of OS/2 Event semaphores).  (Needs a reimplementation (in terms of chaining
+waiting threads, with the linked list stored in per-thread structure?)?)
 
 =item F<os2.c>
 
@@ -2075,7 +2303,7 @@ to system databases.
 
 =head1 AUTHOR
 
-Ilya Zakharevich, ilya@math.ohio-state.edu
+Ilya Zakharevich, cpan@ilyaz.org
 
 =head1 SEE ALSO