*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
+F<.cmd>, F<.btm>, F<.bat>, F<.pl> as well.
+
=head2 Starting OS/2 (and DOS) programs under Perl
This is what system() (see L<perlfunc/system>), C<``> (see
The only cases when the shell is not used is the multi-argument
system() (see L<perlfunc/system>)/exec() (see L<perlfunc/exec>), and
one-argument version thereof without redirection and shell
-meta-characters.
+meta-characters. Perl may also start scripts which start with cookies
+C<extproc> or C<#!> directly, without an intervention of shell.
+
+If starting scripts directly, Perl will use 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>,
+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>.
+
+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 as 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
+extension) give an argument C<n:/bin/blah.> to system().
+
+The last note is that currently it is not straightforward to start PM
+programs from VIO (=text-mode) Perl process and visa versa. Either ensure
+that shell will be used, as in C<system 'cmd /c epm'>, or start it using
+optional arguments to system() documented in C<OS2::Process> module. This
+is considered a bug and should be fixed soon.
+
=head1 Frequently asked questions
=head2 Testing
+If you haven't yet moved perl.dll onto LIBPATH, do it now(alternatively, if
+you have a previous perl installation you'd rather not disrupt until this one
+is installed, copy perl.dll to the t directory).
+
Now run
make test
=head2 Installing the built perl
+If you haven't yet moved perl.dll onto LIBPATH, do it now.
+
Run
make install
=item
-Since L<flock(3)> 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
+Since L<flock(3)> is present in EMX, but is not functional, it is
+emulated by perl. To disable the emulations, set environment variable
+C<USE_PERL_FLOCK=0>.
+
+=item
+
+Here is the list of things which may be "broken" on
EMX (from EMX docs):
=over
=item *
-L<flock(3)> is not yet implemented (dummy function).
+L<flock(3)> is not yet implemented (dummy function). (Perl has a workaround.)
=item *
C<os2_stat> special-cases F</dev/tty> and F</dev/con>.
+=item C<flock>
+
+Since L<flock(3)> is present in EMX, but is not functional, it is
+emulated by perl. To disable the emulations, set environment variable
+C<USE_PERL_FLOCK=0>.
+
=back
=head1 Perl flavors
Specific for EMX port. Gives the directory part of the location for
F<sh.exe>.
+=head2 C<USE_PERL_FLOCK>
+
+Specific for EMX port. Since L<flock(3)> is present in EMX, but is not
+functional, it is emulated by perl. To disable the emulations, set
+environment variable C<USE_PERL_FLOCK=0>.
+
=head2 C<TMP> or C<TEMP>
Specific for EMX port. Used as storage place for temporary files, most