[inseparable changes from patch from perl5.003_25 to perl5.003_26]perl-5.003_26

 CORE LANGUAGE CHANGES

Subject: Make \r in script an error (per Larry)
From: Chip Salzenberg <chip@perl.com>
Files: pod/perldiag.pod toke.c

 CORE PORTABILITY

Subject: VMS patches post _25
Date: Fri, 07 Feb 1997 01:56:12 -0500 (EST)
From: Charles Bailey <bailey@HMIVAX.HUMGEN.UPENN.EDU>
Files: Porting/Glossary lib/ExtUtils/Liblist.pm lib/ExtUtils/MM_VMS.pm lib/ExtUtils/xsubpp perl.c vms/Makefile vms/config.vms vms/descrip.mms vms/genconfig.pl vms/perlvms.pod vms/vms.c vms/vmsish.h x2p/a2p.c

    private-msgid: <01IF48W3P39W0050BD@hmivax.humgen.upenn.edu>

 LIBRARY AND EXTENSIONS

Subject: Make diagnostics module strip formatting directives
From: Chip Salzenberg <chip@perl.com>
Files: lib/diagnostics.pm pod/perldiag.pod

 OTHER CORE CHANGES

Subject: Fix (yet another) Tk closure problem
From: Chip Salzenberg <chip@perl.com>
Files: op.c perl.c pp_ctl.c

Subject: Fix value of C<foreach>
From: Chip Salzenberg <chip@perl.com>
Files: cop.h pp_ctl.c

Subject: Refine 'runaway string' heuristic
From: Chip Salzenberg <chip@perl.com>
Files: toke.c

Subject: Fix core dump on C<print "a", last> in eval
From: Chip Salzenberg <chip@perl.com>
Files: pp_ctl.c

1 files changed, 43 insertions, 13 deletions

diff --git a/vms/perlvms.pod b/vms/perlvms.pod
index e065b08baa..830ff613d5 100644
--- a/vms/perlvms.pod
+++ b/vms/perlvms.pod
@@ -300,7 +300,7 @@ As of the time this document was last revised, the following
 Perl functions were implemented in the VMS port of Perl 
 (functions marked with * are discussed in more detail below):
 
-    file tests*, abs, alarm, atan, binmode*, bless,
+    file tests*, abs, alarm, atan, backticks*, binmode*, bless,
     caller, chdir, chmod, chown, chomp, chop, chr,
     close, closedir, cos, crypt*, defined, delete,
     die, do, dump*, each, endpwent, eof, eval, exec*,
@@ -310,7 +310,7 @@ Perl functions were implemented in the VMS port of Perl
     last, lc, lcfirst, length, local, localtime, log, m//,
     map, mkdir, my, next, no, oct, open, opendir, ord, pack,
     pipe, pop, pos, print, printf, push, q//, qq//, qw//,
-    qx//, quotemeta, rand, read, readdir, redo, ref, rename,
+    qx//*, quotemeta, rand, read, readdir, redo, ref, rename,
     require, reset, return, reverse, rewinddir, rindex,
     rmdir, s///, scalar, seek, seekdir, select(internal),
     select (system call)*, setpwent, shift, sin, sleep,
@@ -375,6 +375,13 @@ only, and then manually check the appropriate bits, as defined by
 your C compiler's F<stat.h>, in the mode value it returns, if you
 need an approximation of the file's protections.
 
+=item backticks
+
+Backticks create a subprocess, and pass the enclosed string
+to it for execution as a DCL command.  Since the subprocess is
+created directly via C<lib$spawn()>, any valid DCL command string
+may be specified.
+
 =item binmode FILEHANDLE
 
 The C<binmode> operator will attempt to insure that no translation
@@ -509,6 +516,10 @@ supervisor-mode images like DCL.)
 Also, negative signal values don't do anything special under
 VMS; they're just converted to the corresponding positive value.
 
+=item qx//
+
+See the entry on C<backticks> above.
+
 =item select (system call)
 
 If Perl was not built with socket support, the system call
@@ -537,7 +548,12 @@ valid DCL command string may be specified.  If LIST consists
 of the empty string, C<system> spawns an interactive DCL subprocess,
 in the same fashion as typiing B<SPAWN> at the DCL prompt.
 Perl waits for the subprocess to complete before continuing
-execution in the current process.
+execution in the current process.  As described in L<perlfunc>,
+the return value of C<system> is a fake "status" which follows
+POSIX semantics; see the description of C<$?> in this document
+for more detail.  The actual VMS exit status of the subprocess
+is available in C<$^S> (as long as you haven't used another Perl
+function that resets C<$?> and C<$^S> in the meantime).
 
 =item time
 
@@ -679,16 +695,6 @@ In all operations on %ENV, the key string is treated as if it
 were entirely uppercase, regardless of the case actually 
 specified in the Perl expression.
 
-=item $?
-
-Since VMS status values are 32 bits wide, the value of C<$?>
-is simply the final status value of the last subprocess to
-complete.  This differs from the behavior of C<$?> under Unix,
-and under VMS' POSIX environment, in that the low-order 8 bits
-of C<$?> do not specify whether the process terminated normally
-or due to a signal, and you do not need to shift C<$?> 8 bits
-to the right in order to find the process' exit status.
-
 =item $!
 
 The string value of C<$!> is that returned by the CRTL's
@@ -710,6 +716,30 @@ is the value of vaxc$errno, and its string value is the
 corresponding VMS message string, as retrieved by sys$getmsg().
 Setting C<$^E> sets vaxc$errno to the value specified.
 
+=item $?
+
+The "status value" returned in C<$?> is synthesized from the
+actual exit status of the subprocess in a way that approximates
+POSIX wait(5) semantics, in order to allow Perl programs to
+portably test for successful completion of subprocesses.  The
+low order 8 bits of C<$?> are always 0 under VMS, since the
+termination status of a process may or may not have been
+generated by an exception.  The next 8 bits are derived from
+severity portion of the subprocess' exit status: if the
+severity was success or informational, these bits are all 0;
+otherwise, they contain the severity value shifted left one bit.
+As a result, C<$?> will always be zero if the subprocess' exit
+status indicated successful completion, and non-zero if a
+warning or error occurred.  The actual VMS exit status may
+be found in C<$^S> (q.v.).
+
+=item $^S
+
+Under VMS, this is the 32-bit VMS status value returned by the
+last subprocess to complete.  Unlink C<$?>, no manipulation
+is done to make this look like a POSIX wait(5) value, so it
+may be treated as a normal VMS status value.
+
 =item $|
 
 Setting C<$|> for an I/O stream causes data to be flushed