From 145d37e29b0763362cc1b261774de4506a62c161 Mon Sep 17 00:00:00 2001
From: Gisle Aas <gisle@aas.no>
Date: Sun, 11 Oct 1998 14:53:13 +0200
Subject: [PATCH] applied suggested patch with small doc tweak 	Message-ID:
 <m3u31bfjza.fsf@furu.g.aas.no> 	Subject: Re: [PATCH 5.005_52] Optional
 syswrite LENGTH argument

p4raw-id: //depot/perl@1992
---
 opcode.h         |  2 +-
 opcode.pl        |  2 +-
 pod/perlfunc.pod |  5 ++++-
 pp_sys.c         |  7 +++++++
 t/op/sysio.t     | 37 ++++++++++++++++++++++++++-----------
 t/op/tiehandle.t | 18 ++++++++++++++++--
 6 files changed, 55 insertions(+), 16 deletions(-)

diff --git a/opcode.h b/opcode.h
index 37b0516..2abaa47 100644
--- a/opcode.h
+++ b/opcode.h
@@ -2385,7 +2385,7 @@ EXT U32 opargs[] = {
 	0x09116504,	/* sysopen */
 	0x00116504,	/* sysseek */
 	0x0917651d,	/* sysread */
-	0x0911651d,	/* syswrite */
+	0x0991651d,	/* syswrite */
 	0x0911651d,	/* send */
 	0x0117651d,	/* recv */
 	0x0000ec14,	/* eof */
diff --git a/opcode.pl b/opcode.pl
index f9c7503..92330a6 100755
--- a/opcode.pl
+++ b/opcode.pl
@@ -519,7 +519,7 @@ print		print			ck_listiob	ims@	F? L
 sysopen		sysopen			ck_fun		s@	F S S S?
 sysseek		sysseek			ck_fun		s@	F S S
 sysread		sysread			ck_fun		imst@	F R S S?
-syswrite	syswrite		ck_fun		imst@	F S S S?
+syswrite	syswrite		ck_fun		imst@	F S S? S?
 
 send		send			ck_fun		imst@	F S S S?
 recv		recv			ck_fun		imst@	F R S S
diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod
index 92a9532..c23aa14 100644
--- a/pod/perlfunc.pod
+++ b/pod/perlfunc.pod
@@ -3988,8 +3988,11 @@ See L<perlop/"`STRING`"> and L</exec> for details.
 
 =item syswrite FILEHANDLE,SCALAR,LENGTH
 
+=item syswrite FILEHANDLE,SCALAR
+
 Attempts to write LENGTH bytes of data from variable SCALAR to the
-specified FILEHANDLE, using the system call write(2).  It bypasses
+specified FILEHANDLE, using the system call write(2).  If LENGTH is
+not specified, writes whole SCALAR. It bypasses
 stdio, so mixing this with reads (other than C<sysread())>, C<print()>,
 C<write()>, C<seek()>, or C<tell()> may cause confusion because stdio usually
 buffers data.  Returns the number of bytes actually written, or C<undef>
diff --git a/pp_sys.c b/pp_sys.c
index 7fa4de2..b613ca8 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -1467,6 +1467,13 @@ PP(pp_sysread)
 
 PP(pp_syswrite)
 {
+    djSP;
+    int items = (SP - PL_stack_base) - TOPMARK;
+    if (items == 2) {
+        EXTEND(SP, 1);
+        PUSHs(sv_2mortal(newSViv(sv_len(*SP))));
+        PUTBACK;
+    }
     return pp_send(ARGS);
 }
 
diff --git a/t/op/sysio.t b/t/op/sysio.t
index 826cf38..0318fed 100755
--- a/t/op/sysio.t
+++ b/t/op/sysio.t
@@ -1,6 +1,6 @@
 #!./perl
 
-print "1..36\n";
+print "1..39\n";
 
 chdir('op') || die "sysio.t: cannot look for myself: $!";
 
@@ -151,6 +151,21 @@ if ($reopen) {  # must close file to update EOF marker for stat
 print 'not ' unless (-s $outfile == 7);
 print "ok 28\n";
 
+# with implicit length argument
+print 'not ' unless (syswrite(O, $x) == 3);
+print "ok 29\n";
+
+# $a still intact
+print 'not ' unless ($x eq "abc");
+print "ok 30\n";
+
+# $outfile should have grown now
+if ($reopen) {  # must close file to update EOF marker for stat
+  close O; open(O, ">>$outfile") || die "sysio.t: cannot write $outfile: $!";
+}
+print 'not ' unless (-s $outfile == 10);
+print "ok 31\n";
+
 close(O);
 
 open(I, $outfile) || die "sysio.t: cannot read $outfile: $!";
@@ -158,30 +173,30 @@ open(I, $outfile) || die "sysio.t: cannot read $outfile: $!";
 $b = 'xyz';
 
 # reading too much only return as much as available
-print 'not ' unless (sysread(I, $b, 100) == 7);
-print "ok 29\n";
+print 'not ' unless (sysread(I, $b, 100) == 10);
+print "ok 32\n";
 # this we should have
-print 'not ' unless ($b eq '#!ererl');
-print "ok 30\n";
+print 'not ' unless ($b eq '#!ererlabc');
+print "ok 33\n";
 
 # test sysseek
 
 print 'not ' unless sysseek(I, 2, 0) == 2;
-print "ok 31\n";
+print "ok 34\n";
 sysread(I, $b, 3);
 print 'not ' unless $b eq 'ere';
-print "ok 32\n";
+print "ok 35\n";
 
 print 'not ' unless sysseek(I, -2, 1) == 3;
-print "ok 33\n";
+print "ok 36\n";
 sysread(I, $b, 4);
 print 'not ' unless $b eq 'rerl';
-print "ok 34\n";
+print "ok 37\n";
 
 print 'not ' unless sysseek(I, 0, 0) eq '0 but true';
-print "ok 35\n";
+print "ok 38\n";
 print 'not ' if defined sysseek(I, -1, 1);
-print "ok 36\n";
+print "ok 39\n";
 
 close(I);
 
diff --git a/t/op/tiehandle.t b/t/op/tiehandle.t
index e3d2472..d7e6a78 100755
--- a/t/op/tiehandle.t
+++ b/t/op/tiehandle.t
@@ -64,7 +64,7 @@ sub READ {
 sub WRITE {
     compare(WRITE => @_);
     $data = substr($_[1],$_[3] || 0, $_[2]);
-    4;
+    length($data);
 }
 
 sub CLOSE {
@@ -77,7 +77,7 @@ package main;
 
 use Symbol;
 
-print "1..23\n";
+print "1..29\n";
 
 my $fh = gensym;
 
@@ -132,6 +132,20 @@ $r = syswrite $fh,$buf,4,1;
 ok($r == 4);
 ok($data eq "wert");
 
+$buf = "qwerty";
+@expect = (WRITE => $ob, $buf, 4);
+$data = "";
+$r = syswrite $fh,$buf,4;
+ok($r == 4);
+ok($data eq "qwer");
+
+$buf = "qwerty";
+@expect = (WRITE => $ob, $buf, 6);
+$data = "";
+$r = syswrite $fh,$buf;
+ok($r == 6);
+ok($data eq "qwerty");
+
 @expect = (CLOSE => $ob);
 $r = close $fh;
 ok($r == 5);
-- 
2.7.4