Re: OS/2 patch for _27

The bulk of this patch is README.os2 which has a lot of formatting
stripped (it is at the end). The rest (340 lines of -u) is quite simple.

INSTALL
	t/harness documented.
lib/Test/Harness.pm
	Can test files with -T on hash-bang line.
	Gets more info from tests which coredump.
	Will not try to load Devel::CoreStack on each test.
os2/Changes
	Updated.
os2/OS2/PrfDB/t/os2_prfdb.t
	File closed.
os2/os2.c
	Poor-man's setup of environment if DLL run from non-conforming EXE.
os2/os2ish.h
	Poor-man's setup of environment if DLL run from non-conforming EXE.
	ALTERNATE_SHEBANG defined.
os2/perl2cmd.pl
	Updated for ALTERNATE_SHEBANG.
perl.c
	If ALTERNATE_SHEBANG defined, just ignore -S on the starting
	line. (It might be already used by OS to start perl.)
pod/perldelta.pod
	Malloc's PERL_DEBUG_MSTATS, EMERGENCY_SBR, PACK_MALLOC,
	TWO_POT_OPTIMIZE documented.
t/harness
	Does not require -I../lib any more.
t/op/magic.t
	Now works under OS/2 with both tests.
t/TEST
	Adds an advice to use 
		perl harness
	to get better granularity.
README.os2
	A lot of markup stripped (in the hope that smart converters
	will add it back), minor updates.

p5p-msgid: <199702210024.TAA03174@monk.mps.ohio-state.edu>

13 files changed, 304 insertions, 151 deletions

diff --git a/INSTALL b/INSTALL
index 156fdd90ed..a74afdb66f 100644
--- a/INSTALL
+++ b/INSTALL
@@ -913,6 +913,14 @@ bomb, you can run them by hand, e.g.,
 
 	./perl op/groups.t
 
+Another way to get more detailed information about failed tests and
+individual subtests is to B<cd> to the F<t> directory and run
+
+	./perl harness
+
+(this assumes that I<most> tests succeed, since F<harness> uses
+complicated constructs).
+
 You can also read the individual tests to see if there are any helpful
 comments that apply to your system.
 
diff --git a/README.os2 b/README.os2
index e6782e3dc1..c0a19601f3 100644
--- a/README.os2
+++ b/README.os2
@@ -27,9 +27,9 @@ A copy of a Win* viewer is contained in the "Just add OS/2 Warp" package
 
   ftp://ftp.software.ibm.com/ps/products/os2/tools/jaow/jaow.zip
 
-in F<?:\JUST_ADD\view.exe>. This gives one an access to B<EMX>'s 
+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 
-B<EMX>'s distribution).
+EMX's distribution).
 
 =cut
 
@@ -43,12 +43,13 @@ Contents
          -  Target 
          -  Other OSes 
          -  Prerequisites 
-         -  Starting Perl programs under OS/2 
-         -  Starting OS/2 programs under Perl 
+         -  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 
@@ -77,9 +78,10 @@ Contents
          -  Some problem (forget which ;-) 
          -  Library ... not found 
          -  Segfault in make 
-      Specific (mis)features of OS/2 port 
+      Specific (mis)features of EMX port 
          -  setpriority, getpriority 
          -  system() 
+         -  extproc on the first line
          -  Additional modules: 
          -  Prebuilt methods: 
          -  Misfeatures 
@@ -113,7 +115,8 @@ Contents
 
 The target is to make OS/2 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.
+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).
 
 The current state is quite close to this target. Known limitations:
 
@@ -131,10 +134,10 @@ to use PM code in your application (like the forthcoming Perl/Tk).
 
 =item *
 
-There is no simple way to access B<WPS> objects. The only way I know
+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
-convenience methods of B<Object REXX>. (Is it possible at all? I know
-of no B<Object-REXX> API.)
+convenience methods of Object-REXX. (Is it possible at all? I know
+of no Object-REXX API.)
 
 =back
 
@@ -142,7 +145,7 @@ Please keep this list up-to-date by informing me about other items.
 
 =head2 Other OSes
 
-Since OS/2 port of perl uses a remarkable B<EMX> environment, it can
+Since OS/2 port of perl uses a remarkable EMX environment, it can
 run (and build extensions, and - possibly - be build itself) under any
 environment which can run EMX. The current list is DOS,
 DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors,
@@ -150,7 +153,7 @@ only one works, see L<"perl_.exe">.
 
 Note that not all features of Perl are available under these
 environments. This depends on the features the I<extender> - most
-probably C<RSX> - decided to implement.
+probably RSX - decided to implement.
 
 Cf. L<Prerequisites>.
 
@@ -158,19 +161,20 @@ Cf. L<Prerequisites>.
 
 =over 6
 
-=item B<EMX>
+=item EMX
 
-B<EMX> runtime is required (may be substituted by B<RSX>). Note that
+EMX runtime is required (may be substituted by RSX). Note that
 it is possible to make F<perl_.exe> to run under DOS without any
 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 B<RSX> runtime, which
+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 B<RSX> is required if there is no C<VCPI> present. Note the
-B<RSX> requires C<DPMI>.
+fact RSX is required if there is no VCPI present. Note the
+RSX requires DPMI.
 
-Only the latest runtime is supported, currently C<0.9c>.
+Only the latest runtime is supported, currently C<0.9c>. Perl may run
+under earlier versions of EMX, but this is not tested.
 
-One can get different parts of B<EMX> from, say
+One can get different parts of EMX from, say
 
   ftp://ftp.cdrom.com/pub/os2/emx0.9c/
   ftp://hobbes.nmsu.edu/os2/unix/gnu/
@@ -184,19 +188,19 @@ does not need to specify them explicitly (though this
 
 will work as well.)
 
-=item B<RSX>
+=item RSX
 
-To run Perl on C<DPMI> platforms one needs B<RSX> runtime. This is
+To run Perl on DPMI platforms one needs RSX runtime. This is
 needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see 
-L<"Other OSes">). B<RSX> would not work with C<VCPI>
-only, as B<EMX> would, it requires C<DMPI>.
+L<"Other OSes">). RSX would not work with VCPI
+only, as EMX would, it requires DMPI.
 
-Having B<RSX> and the latest F<sh.exe> one gets a fully functional
+Having RSX and the latest F<sh.exe> one gets a fully functional
 B<*nix>-ish environment under DOS, say, C<fork>, C<``> and
 pipe-C<open> work. In fact, MakeMaker works (for static build), so one
 can have Perl development environment under DOS. 
 
-One can get B<RSX> from, say
+One can get RSX from, say
 
   ftp://ftp.cdrom.com/pub/os2/emx0.9c/contrib
   ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc
@@ -207,18 +211,32 @@ The latest F<sh.exe> with DOS hooks is available at
 
   ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.exe
 
-=item B<HPFS>
+=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.
 
 Note that if you do not plan to build the perl itself, it may be
-possible to fool B<EMX> to truncate file names. This is not supported,
-read B<EMX> docs to see how to do it.
+possible to fool EMX to truncate file names. This is not supported,
+read EMX docs to see how to do it.
+
+=item pdksh
+
+To start external programs with complicated command lines (like with
+pipes in between, and/or quoting of arguments), Perl uses an external
+shell. With EMX port such shell should be named <sh.exe>, and located
+either in the wired-in-during-compile locations (usually F<F:/bin>),
+or in configurable location (see L<"PERL_SH_DIR">).
+
+For best results use EMX pdksh. The soon-to-be-available standard
+binary (5.2.12?) runs under DOS (with L<RSX>) as well, meanwhile use
+the binary from
+
+  ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.exe
 
 =back
 
-=head2 Starting Perl programs under OS/2
+=head2 Starting Perl programs under OS/2 (and DOS and...)
 
 Start your Perl program F<foo.pl> with arguments C<arg1 arg2 arg3> the
 same way as on any other platform, by
@@ -230,33 +248,28 @@ opposed to to your program), use
 
 	perl -my_opts foo.pl arg1 arg2 arg3
 
-Alternately, if you use OS/2-ish shell, like C<CMD> or C<4os2>, put
+Alternately, if you use OS/2-ish shell, like CMD or 4os2, put
 the following at the start of your perl script:
 
-	extproc perl -x -S
-	#!/usr/bin/perl -my_opts 
+	extproc perl -S -my_opts
 
 rename your program to F<foo.cmd>, and start it by typing
 
 	foo arg1 arg2 arg3
 
-(Note that having *nixish full path to perl F</usr/bin/perl> is not
-necessary, F<perl> would be enough, but having full path would make it
-easier to use your script under *nix.)
-
 Note that because of stupid OS/2 limitations the full path of the perl
 script is not available when you use C<extproc>, thus you are forced to
 use C<-S> perl switch, and your script should be on path. As a plus
 side, if you know a full path to your script, you may still start it
 with 
 
-	perl -x ../../blah/foo.cmd arg1 arg2 arg3
+	perl ../../blah/foo.cmd arg1 arg2 arg3
 
-(note that the argument C<-my_opts> is taken care of by the C<#!> line
-in your script).
+(note that the argument C<-my_opts> is taken care of by the C<extproc> line
+in your script, see L<C<extproc> on the first line>).
 
 To understand what the above I<magic> does, read perl docs about C<-S>
-and C<-x> switches - see L<perlrun>, and cmdref about C<extproc>:
+switch - see L<perlrun>, and cmdref about C<extproc>:
 
 	view perl perlrun
 	man perlrun
@@ -266,11 +279,11 @@ and C<-x> switches - see L<perlrun>, and cmdref about C<extproc>:
 or whatever method you prefer.
 
 There are also endless possibilities to use I<executable extensions> of
-B<4OS2>, I<associations> of B<WPS> and so on... However, if you use
+4os2, I<associations> of WPS and so on... However, if you use
 *nixish shell (like F<sh.exe> supplied in the binary distribution),
 you need to follow the syntax specified in L<perlrun/"Switches">.
 
-=head2 Starting OS/2 programs under Perl
+=head2 Starting OS/2 (and DOS) programs under Perl
 
 This is what system() (see L<perlfunc/system>), C<``> (see
 L<perlop/"I/O Operators">), and I<open pipe> (see L<perlfunc/open>)
@@ -278,7 +291,7 @@ are for. (Avoid exec() (see L<perlfunc/exec>) unless you know what you
 do).
 
 Note however that to use some of these operators you need to have a
-C<sh>-syntax shell installed (see L<"Pdksh">, 
+sh-syntax shell installed (see L<"Pdksh">, 
 L<"Frequently asked questions">), and perl should be able to find it
 (see L<"PERL_SH_DIR">).
 
@@ -296,7 +309,7 @@ meta-characters.
 =item
 
 Did you run your programs with C<-w> switch? See 
-L<Starting OS/2 programs under Perl>.
+L<Starting OS/2 (and DOS) programs under Perl>.
 
 =item
 
@@ -312,12 +325,12 @@ program.
 
 =over 4
 
-=item Is your program B<EMX>-compiled with C<-Zmt -Zcrtdll>?
+=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.
 
-=item Did you use C<ExtUtils::Embed>?
+=item Did you use L<ExtUtils::Embed>?
 
 I had reports it does not work. Somebody would need to fix it.
 
@@ -326,12 +339,29 @@ I had reports it does not work. Somebody would need to fix it.
 =head2 C<``> and pipe-C<open> do not work under DOS.
 
 This may a variant of just L<"I cannot run external programs">, or a
-deeper problem. Basically: you I<need> B<RSX> (see L<"Prerequisites">)
+deeper problem. Basically: you I<need> RSX (see L<"Prerequisites">)
 for these commands to work, and you may need a port of F<sh.exe> which
 understands command arguments. One of such ports is listed in
-L<"Prerequisites"> under B<RSX>.
+L<"Prerequisites"> under RSX. Do not forget to set variable
+C<L<"PERL_SH_DIR">> as well.
+
+DPMI is required for RSX.
+
+=head2 Cannot start C<find.exe "pattern" file>
 
-C<DPMI> is required for B<RSX>.
+Use one of
+
+  system 'cmd', '/c', 'find "pattern" file';
+  `cmd /c 'find "pattern" file'`
+
+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 were
+equivalent:
+
+  find "pattern" file
+  find pattern file
 
 =head1 INSTALLATION
 
@@ -342,9 +372,9 @@ F<install.exe>. Just follow the instructions, and 99% of the
 installation blues would go away. 
 
 Note however, that you need to have F<unzip.exe> on your path, and
-B<EMX> environment I<running>. The latter means that if you just
-installed B<EMX>, and made all the needed changes to F<Config.sys>,
-you may need to reboot in between. Check B<EMX> runtime by running
+EMX environment I<running>. The latter means that if you just
+installed EMX, and made all the needed changes to F<Config.sys>,
+you may need to reboot in between. Check EMX runtime by running
 
 	emxrev
 
@@ -358,7 +388,7 @@ B<Things not taken care of by automatic binary installation:>
 =item C<PERL_BADLANG>
 
 may be needed if you change your codepage I<after> perl installation,
-and the new value is not supported by B<EMX>. See L<"PERL_BADLANG">.
+and the new value is not supported by EMX. See L<"PERL_BADLANG">.
 
 =item C<PERL_BADFREE>
 
@@ -377,19 +407,23 @@ data, please keep me informed if you find one.
 
 =back
 
+B<NOTE>. Because of a typo the binary installer of 5.00305
+would install a variable C<PERL_SHPATH> into F<Config.sys>. Please
+remove this variable and put C<L<PERL_SH_DIR>> instead.
+
 =head2 Manual binary installation
 
 As of version 5.00305, OS/2 perl binary distribution comes split
 into 11 components. Unfortunately, to enable configurable binary
-installation, the file paths in the C<zip> files are not absolute, but
+installation, the file paths in the zip files are not absolute, but
 relative to some directory.
 
 Note that the extraction with the stored paths is still necessary
-(default with C<unzip>, specify C<-d> to C<pkunzip>). However, you
+(default with unzip, specify C<-d> to pkunzip). However, you
 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
-C<pkunzip>), you may get a lot of warnings/errors during
+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
@@ -402,20 +436,20 @@ machine:
   unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
   unzip perl_exc.zip *.dll -d f:/emx.add/dll
 
-(have the directories with C<*.exe> on C<PATH>, and C<*.dll> on
-C<LIBPATH>);
+(have the directories with C<*.exe> on PATH, and C<*.dll> on
+LIBPATH);
 
 =item Perl_ VIO executable (statically linked)
 
   unzip perl_aou.zip -d f:/emx.add/bin
 
-(have the directory on C<PATH>);
+(have the directory on PATH);
 
 =item Executables for Perl utilities
 
   unzip perl_utl.zip -d f:/emx.add/bin
 
-(have the directory on C<PATH>);
+(have the directory on PATH);
 
 =item Main Perl library
 
@@ -447,25 +481,25 @@ C<set PERLLIB_PREFIX> in F<Config.sys>, see L<"PERLLIB_PREFIX">.
   unzip perl_man.zip -d f:/perllib/man
 
 This directory should better be on C<MANPATH>. You need to have a
-working C<man> to access these files.
+working man to access these files.
 
 =item Manpages for Perl modules
 
   unzip perl_mam.zip -d f:/perllib/man
 
 This directory should better be on C<MANPATH>. You need to have a
-working C<man> to access these files.
+working man to access these files.
 
 =item Source for Perl documentation
 
   unzip perl_pod.zip -d f:/perllib/lib
 
 This is used by by C<perldoc> program (see L<perldoc>), and may be used to
-generate B<HTML> documentation usable by WWW browsers, and
+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.
 
-=item Perl manual in .INF format
+=item Perl manual in F<.INF> format
 
   unzip perl_inf.zip -d d:/os2/book
 
@@ -482,7 +516,7 @@ 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 C<sh>-compatible shell
+B<Note.> It may be possible to use some other sh-compatible shell
 (I<not tested>).
 
 =back
@@ -511,7 +545,7 @@ identical) Perl documentation in the following formats:
 
 =head2 OS/2 F<.INF> file
 
-Most probably the most convenient form. View it as
+Most probably the most convenient form. Under OS/2 view it as
 
   view perl
   view perl perlfunc
@@ -519,7 +553,7 @@ Most probably the most convenient form. View it as
   view perl ExtUtils::MakeMaker
 
 (currently the last two may hit a wrong location, but this may improve
-soon).
+soon). Under Win* see L<"SYNOPSIS">.
 
 If you want to build the docs yourself, and have I<OS/2 toolkit>, run
 
@@ -535,7 +569,7 @@ BOOKSHELF path.
 =head2 Plain text
 
 If you have perl documentation in the source form, perl utilities
-installed, and B<GNU> C<groff> installed, you may use 
+installed, and GNU groff installed, you may use 
 
 	perldoc perlfunc
 	perldoc less
@@ -548,7 +582,7 @@ Alternately, try running pod2text on F<.pod> files.
 
 =head2 Manpages
 
-If you have C<man> installed on your system, and you installed perl
+If you have man installed on your system, and you installed perl
 manpages, use something like this:
 
 	man perlfunc
@@ -568,11 +602,11 @@ on our C<MANPATH>, like this
 
   set MANPATH=c:/man;f:/perllib/man
 
-=head2 B<HTML>
+=head2 HTML
 
 If you have some WWW browser available, installed the Perl
 documentation in the source form, and Perl utilities, you can build
-B<HTML> docs. Cd to directory with F<.pod> files, and do like this
+HTML docs. Cd to directory with F<.pod> files, and do like this
 
 	cd f:/perllib/lib/pod
 	pod2html
@@ -582,11 +616,11 @@ directory, and go ahead with reading docs, like this:
 
 	explore file:///f:/perllib/lib/pod/perl.html
 
-Alternatively you may be able to get these docs prebuilt from C<CPAN>.
+Alternatively you may be able to get these docs prebuilt from CPAN.
 
-=head2 B<GNU> C<info> files
+=head2 GNU C<info> files
 
-Users of C<Emacs> would appreciate it very much, especially with
+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.
 
@@ -606,8 +640,8 @@ Here we discuss how to build Perl under OS/2. There is an alternative
 
 =head2 Prerequisites
 
-You need to have the latest B<EMX> development environment, the full
-B<GNU> tool suite (C<gawk> renamed to C<awk>, and B<GNU> F<find.exe>
+You need to have the latest EMX development environment, the full
+GNU tool suite (gawk renamed to awk, and GNU F<find.exe>
 earlier on path than the OS/2 F<find.exe>, same with F<sort.exe>, to
 check use
 
@@ -636,17 +670,17 @@ latter condition by
 
 if you use something like F<CMD.EXE> or latest versions of F<4os2.exe>.
 
-Make sure your C<gcc> is good for C<-Zomf> linking: run C<omflibs>
+Make sure your gcc is good for C<-Zomf> linking: run C<omflibs>
 script in F</emx/lib> directory.
 
-Check that you have C<link386> installed. It comes standard with OS/2,
+Check that you have link386 installed. It comes standard with OS/2,
 but may be not installed due to customization. If typing
 
   link386
 
 shows you do not have it, do I<Selective install>, and choose C<Link
 object modules> in I<Optional system utilities/More>. If you get into
-C<link386>, press C<Ctrl-C>.
+link386, press C<Ctrl-C>.
 
 =head2 Getting perl source
 
@@ -675,10 +709,6 @@ Extract it like this
 You may see a message about errors while extracting F<Configure>. This is
 because there is a conflict with a similarly-named file F<configure>.
 
-Rename F<configure> to F<configure.gnu>. Extract F<Configure> like this
-
-  tar --case-sensitive -vzxf perl5.00409.tar.gz perl5.00409/Configure
-
 Change to the directory of extraction.
 
 =head2 Application of the patches
@@ -692,10 +722,10 @@ F<./os2/POSIX.mkfifo> like this:
 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 B<EMX> distribution
+Note also that the F<db.lib> and F<db.a> from the EMX distribution
 are not suitable for multi-threaded compile (note that currently perl
-is not multithreaded, but is compiled as multithreaded for
-compatibility with B<XFree86>-OS/2). Get a corrected one from
+is not multithread-safe, but is compiled as multithreaded for
+compatibility with XFree86-OS/2). Get a corrected one from
 
   ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip
 
@@ -708,12 +738,12 @@ wrong you find there. I do not expect it is needed anywhere.
 
   sh Configure -des -D prefix=f:/perllib
 
-Prefix means where to install the resulting perl library. Giving
+C<prefix> means: where to install the resulting perl library. Giving
 correct prefix you may avoid the need to specify C<PERLLIB_PREFIX>,
 see L<"PERLLIB_PREFIX">.
 
 I<Ignore the message about missing C<ln>, and about C<-c> option to
-C<tr>>. In fact if you can trace where the latter spurious warning
+tr>. In fact if you can trace where the latter spurious warning
 comes from, please inform me.
 
 Now
@@ -723,9 +753,11 @@ Now
 At some moment the built may die, reporting a I<version mismatch> or
 I<unable to run F<perl>>. This means that most of the build has been
 finished, and it is the time to move the constructed F<perl.dll> to
-some I<absolute> location in C<LIBPATH>. After this done the build
-should finish without a lot of fuss. I<One can avoid it if one has the
-correct prebuilt version of F<perl.dll> on C<LIBPATH>.>
+some I<absolute> location in LIBPATH. After this is done the build
+should finish without a lot of fuss. I<One can avoid the interruption
+if one has the correct prebuilt version of F<perl.dll> on LIBPATH, but
+probably this is not needed anymore, since F<miniperl.exe> is linked
+statically now.>
 
 Warnings which are safe to ignore: I<mkfifo() redefined> inside
 F<POSIX.c>.
@@ -740,7 +772,7 @@ Some tests (4..6) should fail. Some perl invocations should end in a
 segfault (system error C<SYS3175>). To get finer error reports, 
 
   cd t
-  perl -I ../lib harness
+  perl harness
 
 The report you get may look like
 
@@ -753,11 +785,11 @@ The report you get may look like
   Failed 4/140 test scripts, 97.14% okay. 27/2937 subtests failed, 99.08% okay.
 
 Note that using `make test' target two more tests may fail: C<op/exec:1>
-because of (mis)feature of C<pdksh>, and C<lib/posix:15>, which checks
+because of (mis)feature of pdksh, and C<lib/posix:15>, which checks
 that the buffers are not flushed on C<_exit> (this is a bug in the test
 which assumes that tty output is buffered).
 
-I submitted a patch to B<EMX> which makes it possible to fork() with EMX 
+I submitted a patch to EMX which makes it possible to fork() with EMX 
 dynamic libraries loaded, which makes F<lib/io*> tests pass. This means
 that soon the number of failing tests may decrease yet more.
 
@@ -791,12 +823,12 @@ know why this should or should not work.
 
 =item F<lib/io_pipe.t>
 
-Checks C<IO::Pipe> module. Some feature of B<EMX> - test fork()s with
+Checks C<IO::Pipe> module. Some feature of EMX - test fork()s with
 dynamic extension loaded - unsupported now.
 
 =item F<lib/io_sock.t>
 
-Checks C<IO::Socket> module. Some feature of B<EMX> - test fork()s
+Checks C<IO::Socket> module. Some feature of EMX - test fork()s
 with dynamic extension loaded - unsupported now.
 
 =item F<op/stat.t>
@@ -869,14 +901,14 @@ Run
 
 It would put the generated files into needed locations. Manually put
 F<perl.exe>, F<perl__.exe> and F<perl___.exe> to a location on your
-C<PATH>, F<perl.dll> to a location on your C<LIBPATH>.
+PATH, F<perl.dll> to a location on your LIBPATH.
 
 Run
 
   make cmdscripts INSTALLCMDDIR=d:/ir/on/path
 
 to convert perl utilities to F<.cmd> files and put them on
-C<PATH>. You need to put F<.EXE>-utilities on path manually. They are
+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>.
 
@@ -891,7 +923,7 @@ test and install by
   make aout_test
   make aout_install
 
-Manually put F<perl_.exe> to a location on your C<PATH>.
+Manually put F<perl_.exe> to a location on your PATH.
 
 Since C<perl_> has the extensions prebuilt, it does not suffer from
 the I<dynamic extensions + fork()> syndrome, thus the failing tests
@@ -921,13 +953,13 @@ You have a very old pdksh. See L<Prerequisites>.
 
 You do not have MT-safe F<db.lib>. See L<Prerequisites>.
 
-=head2 Problems with C<tr>
+=head2 Problems with tr
 
-reported with very old version of C<tr>.
+reported with very old version of tr.
 
 =head2 Some problem (forget which ;-)
 
-You have an older version of F<perl.dll> on your C<LIBPATH>, which
+You have an older version of F<perl.dll> on your LIBPATH, which
 broke the build of extensions.
 
 =head2 Library ... not found
@@ -936,7 +968,7 @@ You did not run C<omflibs>. See L<Prerequisites>.
 
 =head2 Segfault in make
 
-You use an old version of C<GNU> make. See L<Prerequisites>.
+You use an old version of GNU make. See L<Prerequisites>.
 
 =head1 Specific (mis)features of OS/2 port
 
@@ -952,6 +984,12 @@ Multi-argument form of C<system()> allows an additional numeric
 argument. The meaning of this argument is described in
 L<OS2::Process>.
 
+=head2 C<extproc> on the first line
+
+If the first chars of a script are C<"extproc ">, this line is treated
+as C<#!>-line, thus all the switches on this line are processed (twice
+if script was started via cmd.exe).
+
 =head2 Additional modules:
 
 L<OS2::Process>, L<OS2::REXX>, L<OS2::PrfDB>, L<OS2::ExtAttr>. This
@@ -999,7 +1037,7 @@ means changes with current dir.
 
 =item  C<Cwd::sys_cwd(name)>
 
-Interface to cwd from B<EMX>. Used by C<Cwd::cwd>.
+Interface to cwd from EMX. Used by C<Cwd::cwd>.
 
 =item  C<Cwd::sys_abspath(name, dir)>
 
@@ -1031,7 +1069,7 @@ eventually).
 
 =item
 
-Since <flock> is present in B<EMX>, but is not functional, the same is
+Since <flock> is present in EMX, but is not functional, the same is
 true for perl. Here is the list of things which may be "broken" on
 EMX (from EMX docs):
 
@@ -1054,7 +1092,7 @@ 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 C<pdksh>.
+the current pdksh.
 
 =back
 
@@ -1091,7 +1129,7 @@ C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
 =head1 Perl flavors
 
 Because of idiosyncrasies of OS/2 one cannot have all the eggs in the
-same basket (though C<EMX> environment tries hard to overcome this
+same basket (though EMX environment tries hard to overcome this
 limitations, so the situation may somehow improve). There are 4
 executables for Perl provided by the distribution:
 
@@ -1099,12 +1137,12 @@ executables for Perl provided by the distribution:
 
 The main workhorse. This is a chimera executable: it is compiled as an
 C<a.out>-style executable, but is linked with C<omf>-style dynamic
-library F<perl.dll>, and with dynamic B<CRT> DLL. This executable is a
-C<VIO> application.
+library F<perl.dll>, and with dynamic CRT DLL. This executable is a
+VIO application.
 
 It can load perl dynamic extensions, and it can fork(). Unfortunately,
-with the current version of B<EMX> it cannot fork() with dynamic
-extensions loaded (may be fixed by patches to B<EMX>).
+with the current version of EMX it cannot fork() with dynamic
+extensions loaded (may be fixed by patches to EMX).
 
 B<Note.> Keep in mind that fork() is needed to open a pipe to yourself.
 
@@ -1114,12 +1152,12 @@ This is a statically linked C<a.out>-style executable. It can fork(),
 but cannot load dynamic Perl extensions. The supplied executable has a
 lot of extensions prebuilt, thus there are situations when it can
 perform tasks not possible using F<perl.exe>, like fork()ing when
-having some standard extension loaded. This executable is a C<VIO>
+having some standard extension loaded. This executable is a VIO
 application.
 
 B<Note.> A better behaviour could be obtained from C<perl.exe> if it
 were statically linked with standard I<Perl extensions>, but
-dynamically linked with the I<Perl DLL> and C<CRT> DLL. Then it would
+dynamically linked with the I<Perl DLL> and CRT DLL. Then it would
 be able to fork() with standard extensions, I<and> would be able to
 dynamically load arbitrary extensions. Some changes to Makefiles and
 hint files should be necessary to achieve this.
@@ -1131,27 +1169,27 @@ appropriate extender. See L<"Other OSes">.
 
 =head2 F<perl__.exe>
 
-This is the same executable as <perl___.exe>, but it is a C<PM>
+This is the same executable as F<perl___.exe>, but it is a PM
 application. 
 
-B<Note.> Usually C<STDIN>, C<STDERR>, and C<STDOUT> of a C<PM>
+B<Note.> Usually STDIN, STDERR, and STDOUT of a PM
 application are redirected to C<nul>. However, it is possible to see
 them if you start C<perl__.exe> from a PM program which emulates a
-console window, like I<Shell mode> of C<Emacs> or C<EPM>. Thus it I<is
+console window, like I<Shell mode> of Emacs or EPM. Thus it I<is
 possible> to use Perl debugger (see L<perldebug>) to debug your PM
 application.
 
-This flavor is required if you load extensions which use C<PM>, like
+This flavor is required if you load extensions which use PM, like
 the forthcoming C<Perl/Tk>.
 
 =head2 F<perl___.exe>
 
 This is an C<omf>-style executable which is dynamically linked to
-F<perl.dll> and C<CRT> DLL. I know no advantages of this executable
+F<perl.dll> and CRT DLL. I know no advantages of this executable
 over C<perl.exe>, but it cannot fork() at all. Well, one advantage is
 that the build process is not so convoluted as with C<perl.exe>.
 
-It is a C<VIO> application.
+It is a VIO application.
 
 =head2 Why strange names?
 
@@ -1191,16 +1229,16 @@ this DLL into memory and supplies command-arguments.
 
 This I<greatly> increases the load time for the application (as well as
 the number of problems during compilation). Since interpreter is in a DLL,
-the C<CRT> is basically forced to reside in a DLL as well (otherwise
-extensions would not be able to use C<CRT>).
+the CRT is basically forced to reside in a DLL as well (otherwise
+extensions would not be able to use CRT).
 
 =head2 Why chimera build?
 
-Current C<EMX> environment does not allow DLLs compiled using Unixish
+Current EMX environment does not allow DLLs compiled using Unixish
 C<a.out> format to export symbols for data. This forces C<omf>-style
 compile of F<perl.dll>.
 
-Current C<EMX> environment does not allow F<.EXE> files compiled in
+Current EMX environment does not allow F<.EXE> files compiled in
 C<omf> format to fork(). fork() is needed for exactly three Perl
 operations:
 
@@ -1225,12 +1263,12 @@ F<perl.exe>.
 
 =head1 ENVIRONMENT
 
-Here we list environment variables with are either OS/2-specific, or
-are more important under OS/2 than under other OSes.
+Here we list environment variables with are either OS/2- and DOS- and
+Win*-specific, or are more important under OS/2 than under other OSes.
 
 =head2 C<PERLLIB_PREFIX>
 
-Specific for OS/2. Should have the form
+Specific for EMX port. Should have the form
 
   path1;path2
 
@@ -1258,12 +1296,12 @@ memory handling code is buggy.
 
 =head2 C<PERL_SH_DIR>
 
-Specific for OS/2. Gives the directory part of the location for
+Specific for EMX port. Gives the directory part of the location for
 F<sh.exe>.
 
 =head2 C<TMP> or C<TEMP>
 
-Specific for OS/2. Used as storage place for temporary files, most
+Specific for EMX port. Used as storage place for temporary files, most
 notably C<-e> scripts.
 
 =head1 Evolution
@@ -1284,12 +1322,12 @@ caching DLLs.
 
 =head2 Threading
 
-As of release 5.003_01 perl is linked to multithreaded C<CRT>
+As of release 5.003_01 perl is linked to multithreaded CRT
 DLL. Perl itself is not multithread-safe, as is not perl
 malloc(). However, extensions may use multiple thread on their own
 risk. 
 
-Needed to compile C<Perl/Tk> for C<XFreeOS/2> out-of-the-box.
+Needed to compile C<Perl/Tk> for XFree86-OS/2 out-of-the-box.
 
 =head2 Calls to external programs
 
@@ -1307,9 +1345,11 @@ B<Reasons:> a consensus on C<perl5-porters> was that perl should use
 one non-overridable shell per platform. The obvious choices for OS/2
 are F<cmd.exe> and F<sh.exe>. Having perl build itself would be impossible
 with F<cmd.exe> as a shell, thus I picked up C<sh.exe>. Thus assures almost
-100% compatibility with the scripts coming from *nix.
+100% compatibility with the scripts coming from *nix. As an added benefit 
+this works as well under DOS if you use DOS-enabled port of pdksh 
+(see L<"Prerequisites">).
 
-B<Disadvantages:> currently F<sh.exe> of C<pdksh> calls external programs
+B<Disadvantages:> currently F<sh.exe> of pdksh calls external programs
 via fork()/exec(), and there is I<no> functioning exec() on
 OS/2. exec() is emulated by EMX by asyncroneous call while the caller
 waits for child completion (to pretend that the C<pid> did not change). This
@@ -1370,7 +1410,8 @@ there are OS2::ExtAttr, OS2::PrfDB for tied access to EAs and .INI
 files - and maybe some other extensions at the time you read it.
 
 Note that OS2 perl defines 2 pseudo-extension functions
-OS2::Copy::copy and DynaLoader::mod2fname.
+OS2::Copy::copy and DynaLoader::mod2fname (many more now, see
+L<Prebuilt methods>).
 
 The -R switch of older perl is deprecated. If you need to call a REXX code
 which needs access to variables, include the call into a REXX compartment
diff --git a/lib/Test/Harness.pm b/lib/Test/Harness.pm
index ba0683a02e..e2bb89eb5a 100644
--- a/lib/Test/Harness.pm
+++ b/lib/Test/Harness.pm
@@ -60,9 +60,14 @@ sub runtests {
 	chop($te);
 	print "$te" . '.' x (20 - length($te));
 	my $fh = new FileHandle;
-	my $cmd = "$^X $switches $test|";
+	$fh->open($test) or print "can't open $test. $!\n";
+	my $first = <$fh>;
+	my $s = $switches;
+	$s .= " -T" if $first =~ /^#!.*\bperl.*-\w*T/;
+	$fh->close or print "can't close $test. $!\n";
+	my $cmd = "$^X $s $test|";
 	$cmd = "MCR $cmd" if $^O eq 'VMS';
-	$fh->open($cmd) or print "can't run. $!\n";
+	$fh->open($cmd) or print "can't run $test. $!\n";
 	$ok = $next = $max = 0;
 	@failed = ();
 	while (<$fh>) {
@@ -100,6 +105,7 @@ sub runtests {
 	my $wstatus = $?;
 	my $estatus = $^O eq 'VMS' ? $wstatus : $wstatus >> 8;
 	if ($^O eq 'VMS' ? !($wstatus & 1) : $wstatus) {
+	    my ($failed, $canon, $percent) = ('??', '??');
 	    print "dubious\n\tTest returned status $estatus (wstat $wstatus)\n";
 	    if (corestatus($wstatus)) { # until we have a wait module
 		if ($have_devel_corestack) {
@@ -109,9 +115,22 @@ sub runtests {
 		}
 	    }
 	    $bad++;
-	    $failedtests{$test} = { canon => '??',  max => $max || '??',
-				    failed => '??', 
-				    name => $test, percent => undef,
+	    if ($max) {
+	      if ($next == $max + 1 and not @failed) {
+		print "\tafter all the subtests completed successfully\n";
+		$percent = 0;
+		$failed = 0;	# But we do not set $canon!
+	      } else {
+		push @failed, $next..$max;
+		$failed = @failed;
+		(my $txt, $canon) = canonfailed($max,@failed);
+		$percent = 100*(scalar @failed)/$max;
+		print "DIED. ",$txt;
+	      }
+	    }
+	    $failedtests{$test} = { canon => $canon,  max => $max || '??',
+				    failed => $failed, 
+				    name => $test, percent => $percent,
 				    estat => $estatus, wstat => $wstatus,
 				  };
 	} elsif ($ok == $max && $next == $max+1) {
@@ -186,6 +205,7 @@ sub runtests {
     return ($bad == 0 && $totmax) ;
 }
 
+my $tried_devel_corestack;
 sub corestatus {
     my($st) = @_;
     my($ret);
@@ -199,8 +219,8 @@ sub corestatus {
 	$ret = WCOREDUMP($st);
     }
 
-    eval {require Devel::CoreStack};
-    $have_devel_corestack++ unless $@;
+    eval { require Devel::CoreStack; $have_devel_corestack++ } 
+      unless $tried_devel_corestack++;
 
     $ret;
 }
diff --git a/os2/Changes b/os2/Changes
index 4691e5bd35..15fad979f3 100644
--- a/os2/Changes
+++ b/os2/Changes
@@ -133,3 +133,13 @@ after 5.003_21:
 	'script.sh'. Form without extension will call shell only if
 	the specified file exists (will not look on path) (to prohibit
 	trying to run shell commands directly). - Needed by magic.t.
+
+after 5.003_27:
+	ALTERNATE_SHEBANG="extproc " supported, thus options on this
+	line are processed (possibly twice). -S is made legal on such
+	a line. This -S -x is not needed any more.
+	perl.dll may be used from non-EMX programs (via PERL_SYS_INIT
+	- the caller should have valid variable "env" with
+	environment). Known problems: $$ does not work - is 0, waitpid
+	returns immediately, thus Perl cannot wait for completion of
+	started programs.
diff --git a/os2/OS2/PrfDB/t/os2_prfdb.t b/os2/OS2/PrfDB/t/os2_prfdb.t
index a8c9752d36..b9f7d90ae2 100644
--- a/os2/OS2/PrfDB/t/os2_prfdb.t
+++ b/os2/OS2/PrfDB/t/os2_prfdb.t
@@ -88,6 +88,8 @@ print( OS2::Prf::Set($ini,'bbb', 'xxx','abc') ? "ok 18\n" :
 print( OS2::Prf::Set($ini,'bbb', 'yyy','456') ? "ok 19\n" :
     "not ok 19\n# err: `$^E'\n");
 
+OS2::Prf::Close($ini);
+
 my %hash1;
 
 tie %hash1, 'OS2::PrfDB::Sub', $inifile, 'aaa';
diff --git a/os2/os2.c b/os2/os2.c
index 017230ff0b..f8f4a82735 100644
--- a/os2/os2.c
+++ b/os2/os2.c
@@ -1139,12 +1139,15 @@ Xs_OS2_init()
 OS2_Perl_data_t OS2_Perl_data;
 
 void
-Perl_OS2_init()
+Perl_OS2_init(char **env)
 {
     char *shell;
 
     settmppath();
     OS2_Perl_data.xs_init = &Xs_OS2_init;
+    if (environ == NULL) {
+	environ = env;
+    }
     if ( (shell = getenv("PERL_SH_DRIVE")) ) {
 	New(404, sh_path, strlen(SH_PATH) + 1, char);
 	strcpy(sh_path, SH_PATH);
diff --git a/os2/os2ish.h b/os2/os2ish.h
index 7cf56fe79b..06a92a31fb 100644
--- a/os2/os2ish.h
+++ b/os2/os2ish.h
@@ -47,7 +47,7 @@
  *	(IOW, Perl won't hand off to another interpreter via an alternate
  *	shebang sequence that might be legal Perl code.)
  */
-/* #define ALTERNATE_SHEBANG "#!" / **/
+#define ALTERNATE_SHEBANG "extproc "
 
 #ifndef SIGABRT
 #    define SIGABRT SIGILL
@@ -64,12 +64,14 @@
 # undef I_SYS_UN
 #endif 
  
-void Perl_OS2_init();
+void Perl_OS2_init(char **);
+
+/* XXX This code hideously puts env inside: */
 
 #define PERL_SYS_INIT(argcp, argvp) STMT_START {	\
     _response(argcp, argvp);			\
     _wildcard(argcp, argvp);			\
-    Perl_OS2_init();	} STMT_END
+    Perl_OS2_init(env);	} STMT_END
 
 #define PERL_SYS_TERM()
 
diff --git a/os2/perl2cmd.pl b/os2/perl2cmd.pl
index c17ab761aa..f9cc03bdac 100644
--- a/os2/perl2cmd.pl
+++ b/os2/perl2cmd.pl
@@ -23,7 +23,7 @@ foreach $file (<$idir/*>) {
   $base =~ s|.*/||;
   $file =~ s|/|\\|g ;
   print "Processing $file => $dir\\$base.cmd\n";
-  system 'cmd.exe', '/c', "echo extproc perl -Sx > $dir\\$base.cmd";
+  system 'cmd.exe', '/c', "echo extproc perl -S>$dir\\$base.cmd";
   system 'cmd.exe', '/c', "type $file >> $dir\\$base.cmd";
 }
 
diff --git a/perl.c b/perl.c
index 24df71a56f..be2f7d8d38 100644
--- a/perl.c
+++ b/perl.c
@@ -1438,6 +1438,10 @@ GNU General Public License, which may be found in the Perl 5.0 source kit.\n\n")
     case 'P':
 	if (preprocess)
 	    return s+1;
+#ifdef ALTERNATE_SHEBANG
+    case 'S':			/* OS/2 needs -S on "extproc" line. */
+	break;
+#endif
 	/* FALL THROUGH */
     default:
 	croak("Can't emulate -%.1s on #! line",s);
diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index ab5cde38ff..08c0a2d066 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -331,7 +331,7 @@ possibly for cleaning up.
 
 =back
 
-=item Efficiency Enhancements
+=head2 Efficiency Enhancements
 
 All hash keys with the same string are only allocated once, so
 even if you have 100 copies of the same hash, the immutable keys
@@ -340,6 +340,60 @@ never have to be re-allocated.
 Functions that have an empty prototype and that do nothing but return
 a fixed value are now inlined (e.g. C<sub PI () { 3.14159 }>).
 
+=head2 Malloc Enhancements
+
+If perl's malloc() is used, you can require memory statistics at
+runtime by running perl thusly:
+
+  env PERL_DEBUG_MSTATS=2 perl your_script_here
+
+The value of 2 means that the statistics is required after the
+compilation and on exit, if value is 1 the statistics is printed on
+exit only. (If you want the statistics at an arbitrary time, you need
+to install an optional module Devel::Peek.)
+
+Three new flags are recognized by malloc.c. (They have no effect if
+perl is compiled with system malloc().)
+
+=over
+
+=item B<-D>C<EMERGENCY_SBRK>
+
+If defined, running out of memory may be not a fatal error if a memory
+pool is allocated by assigning to variable $^M, see L<"$^M">.
+
+=item B<-D>C<PACK_MALLOC>
+
+Perl memory allocation is by bucket with sizes close to powers of
+two. Because of these malloc overhead may be big, especially for data
+of size exactly a power of two. If C<PACK_MALLOC> is defined, perl
+uses a slightly different algorithm for small allocations (up to 64
+bytes long), which makes it possible to have overhead down to 1 byte
+for allocations which are powers of two (and appear quite often).
+
+Expected memory savings (with 8-byte alignment in C<alignbytes>) are
+circa 20% for typical Perl usage. Expected slowdown due to additional
+malloc overhead is in fractions of percent (hard to measure, because
+of the effect of saved memory on speed).
+
+=item B<-D>C<TWO_POT_OPTIMIZE>
+
+Similarly to C<PACK_MALLOC>, this improves allocations of data with
+size close ot power of two, only it works for big allocations
+(starting with 16K by default). Such allocations are typical for big
+hashes and special-purpose scripts, say, image processing.
+
+On young systems the fact that perl requires 2M from system for 1M
+allocation will not affect the speed, since the tail of such a chunk
+is not going to be touched, however, this may affect the maximal
+number of allocations (unless the system overcommits memory).
+
+Expected saving of memory is 0-100% (100% in applications which
+require most memory in such 2**n chunks), expected slowdown
+negligible.
+
+=back
+
 =head1 Pragmata
 
 Four new pragmatic modules exist:
diff --git a/t/TEST b/t/TEST
index 96c5ab26a4..215138ef90 100755
--- a/t/TEST
+++ b/t/TEST
@@ -126,6 +126,13 @@ if ($bad == 0) {
    ### of them individually and examine any diagnostic messages they
    ### produce.  See the INSTALL document's section on "make test".
 SHRDLU
+       warn <<'SHRDLU' if $good / $total > 0.8;
+   ###
+   ### Since most tests were successful, you have a good chance to
+   ### get information with better granularity by running
+   ###     ./perl harness
+   ### in directory ./t.
+SHRDLU
 }
 ($user,$sys,$cuser,$csys) = times;
 print sprintf("u=%g  s=%g  cu=%g  cs=%g  scripts=%d  tests=%d\n",
diff --git a/t/harness b/t/harness
index 5b460f3de4..18feb32dc3 100755
--- a/t/harness
+++ b/t/harness
@@ -3,8 +3,9 @@
 # We suppose that perl _mostly_ works at this moment, so may use
 # sophisticated testing.
 
-# Note that _before install_ you may need to run it with -I ../lib flag
-
+BEGIN {
+  unshift @INC, '../lib';	# To get lib.pm
+}
 use lib '../lib';
 use Test::Harness;
 
diff --git a/t/op/magic.t b/t/op/magic.t
index bb65ae8b7a..789c60a93c 100755
--- a/t/op/magic.t
+++ b/t/op/magic.t
@@ -104,12 +104,13 @@ else {
     $wd = '.';
 }
 $script = "$wd/show-shebang";
+$s = "\$^X is $wd/perl, \$0 is $script\n";
 if ($^O eq 'os2') {
     # Started by ksh, which adds suffixes '.exe' and '.' to perl and script
-    $s = "\$^X is $wd/perl.exe, \$0 is $script.\n";
+    $s1 = "\$^X is $wd/perl.exe, \$0 is $script.\n";
 }
 else {
-    $s = "\$^X is $wd/perl, \$0 is $script\n";
+    $s1 = $s;
 }
 ok 19, open(SCRIPT, ">$script"), $!;
 ok 20, print(SCRIPT <<EOB . <<'EOF'), $!;
@@ -121,9 +122,9 @@ ok 21, close(SCRIPT), $!;
 ok 22, chmod(0755, $script), $!;
 $_ = `$script`;
 s{is perl}{is $wd/perl}; # for systems where $^X is only a basename
-ok 23, $_ eq $s, ":$_:!=:$s:";
+ok 23, $_ eq $s1, ":$_:!=:$s1:";
 $_ = `$wd/perl $script`;
-ok 24, $_ eq $s, ":$_:!=:$s:";
+ok 24, $_ eq $s, ":$_:!=:$s: after `$wd/perl $script`";
 ok 25, unlink($script), $!;
 
 # $], $^O, $^T