$0 mofifying part I

Subject: [PATCH] $0 modifying
Message-ID: <20021130181651.GA5876@kosh.hut.fi>

p4raw-id: //depot/perl@18229

1 files changed, 28 insertions, 1 deletions

diff --git a/ext/threads/t/join.t b/ext/threads/t/join.t
index f2c88d524b..892f48d055 100644
--- a/ext/threads/t/join.t
+++ b/ext/threads/t/join.t
@@ -11,7 +11,7 @@ BEGIN {
 
 use ExtUtils::testlib;
 use strict;
-BEGIN { print "1..10\n" };
+BEGIN { print "1..11\n" };
 use threads;
 use threads::shared;
 
@@ -87,3 +87,30 @@ ok(1,"");
     })->join();
     ok(1,"");
 }
+
+if ($^O eq 'linux') { # We parse ps output so this is OS-dependent.
+
+  # First modify $0 in a subthread.
+  print "# 1a: \$0 = $0\n";
+  join( threads->new( sub {
+	print "# 2a: \$0 = $0\n";
+	$0 = "foobar";
+	print "# 2b: \$0 = $0\n" } ) );
+  print "# 1b: \$0 = $0\n";
+  if (open PS, "ps -f |") {
+    my $ok;
+    while (<PS>) {
+      print "# $_";
+      if (/^\S+\s+$$\s.+\sfoobar\s*$/) {
+	$ok++;
+	last;
+      }
+    }
+    close PS;
+    ok($ok, 'altering $0 is effective');
+  } else {
+    skip("\$0 check: opening 'ps -f |' failed: $!");
+  }
+} else {
+  skip("\$0 check: only on Linux");
+}