environment). Known problems: $$ does not work - is 0, waitpid
returns immediately, thus Perl cannot wait for completion of
started programs.
+
+after 5.004_01:
+ flock emulation added (disable by setting env PERL_USE_FLOCK=0),
+ thanks to Rocco Caputo;
+ RSX bug with missing waitpid circomvented;
+ -S bug with full path with \ corrected.
+
+before 5.004_02:
+ -S switch to perl enables a search with additional extensions
+ .cmd, .btm, .bat, .pl as well. This means that if you have
+ mycmd.pl or mycmd.bat on PATH,
+ perl -S mycmd
+ will work. Perl will also look in the current directory first.
+ Moreover, a bug with \; in PATH being non-separator is fixed.
+
+after 5.004_03:
+ $^E tracks calls to CRT now. (May break if Perl masks some
+ changes to errno?)
+ $0 may be edited to longer lengths (at least under OS/2).
+ OS2::REXX->loads looks in the OS/2-ish fashion too.
+
+after 5.004_04:
+ Default perl.exe was built with a shorter stack than expected.
+ Strip extensions DLLs too (unless debugging build).
+ ./os2.c being RO could stop cp.
+ When starting scripts, Perl will find them on path (using the same
+ extensions as for -S command-line switch). If it finds magic
+ `extproc ' or `#!' cookies, it will start the scripts directly.
+ May use `cmd /c more <' as a pager.
+ If a program could not be started, this might have been hidden.
+ End of pipe was closed twice when `open'ing a pipeline.
+
+after 5.004_53:
+ Minimal thread support added. One needs to manually move pthread.h
+
+after 5.004_64:
+ Make DLL names different if thread-enabled.
+ Emit more informative internal DLL descriptions.