all: single space after period

Follow CL 20022 and consistently use single space after a period in
documentation.

Generated with:

$ perl -i -npe 's,^(\s*// .+[a-z]\.)  +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.)  +([A-Z])')

Change-Id: Ia29ad823668f060e81293e848a79fc4b4857d94b
Reviewed-on: https://go-review.googlesource.com/73530
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/unix/creds_test.go b/unix/creds_test.go
index 7ae3305..4557ea4 100644
--- a/unix/creds_test.go
+++ b/unix/creds_test.go
@@ -1,4 +1,4 @@
-// Copyright 2012 The Go Authors.  All rights reserved.
+// Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/env_unix.go b/unix/env_unix.go
index 45e281a..2e06b33 100644
--- a/unix/env_unix.go
+++ b/unix/env_unix.go
@@ -1,4 +1,4 @@
-// Copyright 2010 The Go Authors.  All rights reserved.
+// Copyright 2010 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/env_unset.go b/unix/env_unset.go
index 9222262..c44fdc4 100644
--- a/unix/env_unset.go
+++ b/unix/env_unset.go
@@ -1,4 +1,4 @@
-// Copyright 2014 The Go Authors.  All rights reserved.
+// Copyright 2014 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/export_test.go b/unix/export_test.go
index b4fdd97..e802469 100644
--- a/unix/export_test.go
+++ b/unix/export_test.go
@@ -1,4 +1,4 @@
-// Copyright 2015 The Go Authors.  All rights reserved.
+// Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/gccgo.go b/unix/gccgo.go
index 94c8232..40bed3f 100644
--- a/unix/gccgo.go
+++ b/unix/gccgo.go
@@ -1,4 +1,4 @@
-// Copyright 2015 The Go Authors.  All rights reserved.
+// Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
@@ -8,7 +8,7 @@
 
 import "syscall"
 
-// We can't use the gc-syntax .s files for gccgo.  On the plus side
+// We can't use the gc-syntax .s files for gccgo. On the plus side
 // much of the functionality can be written directly in Go.
 
 //extern gccgoRealSyscall
diff --git a/unix/gccgo_c.c b/unix/gccgo_c.c
index 07f6be0..99a774f 100644
--- a/unix/gccgo_c.c
+++ b/unix/gccgo_c.c
@@ -1,4 +1,4 @@
-// Copyright 2015 The Go Authors.  All rights reserved.
+// Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/gccgo_linux_amd64.go b/unix/gccgo_linux_amd64.go
index bffe1a7..251a977 100644
--- a/unix/gccgo_linux_amd64.go
+++ b/unix/gccgo_linux_amd64.go
@@ -1,4 +1,4 @@
-// Copyright 2015 The Go Authors.  All rights reserved.
+// Copyright 2015 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/pagesize_unix.go b/unix/pagesize_unix.go
index 45afcf7..83c85e0 100644
--- a/unix/pagesize_unix.go
+++ b/unix/pagesize_unix.go
@@ -1,4 +1,4 @@
-// Copyright 2017 The Go Authors.  All rights reserved.
+// Copyright 2017 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/race.go b/unix/race.go
index 3c7627e..61712b5 100644
--- a/unix/race.go
+++ b/unix/race.go
@@ -1,4 +1,4 @@
-// Copyright 2012 The Go Authors.  All rights reserved.
+// Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/race0.go b/unix/race0.go
index f8678e0..dd08204 100644
--- a/unix/race0.go
+++ b/unix/race0.go
@@ -1,4 +1,4 @@
-// Copyright 2012 The Go Authors.  All rights reserved.
+// Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/sockcmsg_linux.go b/unix/sockcmsg_linux.go
index d9ff473..6079eb4 100644
--- a/unix/sockcmsg_linux.go
+++ b/unix/sockcmsg_linux.go
@@ -1,4 +1,4 @@
-// Copyright 2011 The Go Authors.  All rights reserved.
+// Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
diff --git a/unix/syscall.go b/unix/syscall.go
index 432d257..d048da8 100644
--- a/unix/syscall.go
+++ b/unix/syscall.go
@@ -5,10 +5,10 @@
 // +build darwin dragonfly freebsd linux netbsd openbsd solaris
 
 // Package unix contains an interface to the low-level operating system
-// primitives.  OS details vary depending on the underlying system, and
+// primitives. OS details vary depending on the underlying system, and
 // by default, godoc will display OS-specific documentation for the current
-// system.  If you want godoc to display OS documentation for another
-// system, set $GOOS and $GOARCH to the desired system.  For example, if
+// system. If you want godoc to display OS documentation for another
+// system, set $GOOS and $GOARCH to the desired system. For example, if
 // you want to view documentation for freebsd/arm on linux/amd64, set $GOOS
 // to freebsd and $GOARCH to arm.
 // The primary use of this package is inside other packages that provide a more
diff --git a/unix/syscall_bsd.go b/unix/syscall_bsd.go
index c2846b3..695914e 100644
--- a/unix/syscall_bsd.go
+++ b/unix/syscall_bsd.go
@@ -34,7 +34,7 @@
 		return nil, nil
 	}
 
-	// Sanity check group count.  Max is 16 on BSD.
+	// Sanity check group count. Max is 16 on BSD.
 	if n < 0 || n > 1000 {
 		return nil, EINVAL
 	}
diff --git a/unix/syscall_darwin.go b/unix/syscall_darwin.go
index 4e92bba..6ecb66e 100644
--- a/unix/syscall_darwin.go
+++ b/unix/syscall_darwin.go
@@ -54,7 +54,7 @@
 
 	// NOTE(rsc): It seems strange to set the buffer to have
 	// size CTL_MAXNAME+2 but use only CTL_MAXNAME
-	// as the size.  I don't know why the +2 is here, but the
+	// as the size. I don't know why the +2 is here, but the
 	// kernel uses +2 for its own implementation of this function.
 	// I am scared that if we don't include the +2 here, the kernel
 	// will silently write 2 words farther than we specify
diff --git a/unix/syscall_darwin_386.go b/unix/syscall_darwin_386.go
index 8d98675..b3ac109 100644
--- a/unix/syscall_darwin_386.go
+++ b/unix/syscall_darwin_386.go
@@ -22,7 +22,7 @@
 //sysnb	gettimeofday(tp *Timeval) (sec int32, usec int32, err error)
 func Gettimeofday(tv *Timeval) (err error) {
 	// The tv passed to gettimeofday must be non-nil
-	// but is otherwise unused.  The answers come back
+	// but is otherwise unused. The answers come back
 	// in the two registers.
 	sec, usec, err := gettimeofday(tv)
 	tv.Sec = int32(sec)
diff --git a/unix/syscall_darwin_amd64.go b/unix/syscall_darwin_amd64.go
index fe2bdb3..7521944 100644
--- a/unix/syscall_darwin_amd64.go
+++ b/unix/syscall_darwin_amd64.go
@@ -22,7 +22,7 @@
 //sysnb	gettimeofday(tp *Timeval) (sec int64, usec int32, err error)
 func Gettimeofday(tv *Timeval) (err error) {
 	// The tv passed to gettimeofday must be non-nil
-	// but is otherwise unused.  The answers come back
+	// but is otherwise unused. The answers come back
 	// in the two registers.
 	sec, usec, err := gettimeofday(tv)
 	tv.Sec = sec
diff --git a/unix/syscall_darwin_arm.go b/unix/syscall_darwin_arm.go
index d6d5573..47ab664 100644
--- a/unix/syscall_darwin_arm.go
+++ b/unix/syscall_darwin_arm.go
@@ -20,7 +20,7 @@
 //sysnb	gettimeofday(tp *Timeval) (sec int32, usec int32, err error)
 func Gettimeofday(tv *Timeval) (err error) {
 	// The tv passed to gettimeofday must be non-nil
-	// but is otherwise unused.  The answers come back
+	// but is otherwise unused. The answers come back
 	// in the two registers.
 	sec, usec, err := gettimeofday(tv)
 	tv.Sec = int32(sec)
diff --git a/unix/syscall_darwin_arm64.go b/unix/syscall_darwin_arm64.go
index 2ab03d1..d6d9628 100644
--- a/unix/syscall_darwin_arm64.go
+++ b/unix/syscall_darwin_arm64.go
@@ -22,7 +22,7 @@
 //sysnb	gettimeofday(tp *Timeval) (sec int64, usec int32, err error)
 func Gettimeofday(tv *Timeval) (err error) {
 	// The tv passed to gettimeofday must be non-nil
-	// but is otherwise unused.  The answers come back
+	// but is otherwise unused. The answers come back
 	// in the two registers.
 	sec, usec, err := gettimeofday(tv)
 	tv.Sec = sec
diff --git a/unix/syscall_freebsd.go b/unix/syscall_freebsd.go
index 4c0d2f4..597808f 100644
--- a/unix/syscall_freebsd.go
+++ b/unix/syscall_freebsd.go
@@ -32,7 +32,7 @@
 
 	// NOTE(rsc): It seems strange to set the buffer to have
 	// size CTL_MAXNAME+2 but use only CTL_MAXNAME
-	// as the size.  I don't know why the +2 is here, but the
+	// as the size. I don't know why the +2 is here, but the
 	// kernel uses +2 for its own implementation of this function.
 	// I am scared that if we don't include the +2 here, the kernel
 	// will silently write 2 words farther than we specify
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index 4520328..9b319e5 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go
@@ -255,7 +255,7 @@
 		return nil, nil
 	}
 
-	// Sanity check group count.  Max is 1<<16 on Linux.
+	// Sanity check group count. Max is 1<<16 on Linux.
 	if n < 0 || n > 1<<20 {
 		return nil, EINVAL
 	}
@@ -290,8 +290,8 @@
 // 0x7F (stopped), or a signal number that caused an exit.
 // The 0x80 bit is whether there was a core dump.
 // An extra number (exit code, signal causing a stop)
-// is in the high bits.  At least that's the idea.
-// There are various irregularities.  For example, the
+// is in the high bits. At least that's the idea.
+// There are various irregularities. For example, the
 // "continued" status is 0xFFFF, distinguishing itself
 // from stopped via the core dump bit.
 
@@ -1023,7 +1023,7 @@
 
 	var buf [sizeofPtr]byte
 
-	// Leading edge.  PEEKTEXT/PEEKDATA don't require aligned
+	// Leading edge. PEEKTEXT/PEEKDATA don't require aligned
 	// access (PEEKUSER warns that it might), but if we don't
 	// align our reads, we might straddle an unmapped page
 	// boundary and not get the bytes leading up to the page
diff --git a/unix/syscall_linux_386.go b/unix/syscall_linux_386.go
index b4cfe17..4774fa3 100644
--- a/unix/syscall_linux_386.go
+++ b/unix/syscall_linux_386.go
@@ -176,9 +176,9 @@
 
 // On x86 Linux, all the socket calls go through an extra indirection,
 // I think because the 5-register system call interface can't handle
-// the 6-argument calls like sendto and recvfrom.  Instead the
+// the 6-argument calls like sendto and recvfrom. Instead the
 // arguments to the underlying system call are the number below
-// and a pointer to an array of uintptr.  We hide the pointer in the
+// and a pointer to an array of uintptr. We hide the pointer in the
 // socketcall assembly to avoid allocation on every system call.
 
 const (
diff --git a/unix/syscall_solaris.go b/unix/syscall_solaris.go
index 35e5d72..80be790 100644
--- a/unix/syscall_solaris.go
+++ b/unix/syscall_solaris.go
@@ -166,7 +166,7 @@
 
 func Getgroups() (gids []int, err error) {
 	n, err := getgroups(0, nil)
-	// Check for error and sanity check group count.  Newer versions of
+	// Check for error and sanity check group count. Newer versions of
 	// Solaris allow up to 1024 (NGROUPS_MAX).
 	if n < 0 || n > 1024 {
 		if err != nil {
@@ -350,7 +350,7 @@
 }
 
 // Solaris doesn't have an futimes function because it allows NULL to be
-// specified as the path for futimesat.  However, Go doesn't like
+// specified as the path for futimesat. However, Go doesn't like
 // NULL-style string interfaces, so this simple wrapper is provided.
 func Futimes(fd int, tv []Timeval) error {
 	if tv == nil {