6623 iostat -exrn has missing comma (field separator) in header
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>

*** 27,36 ****
--- 27,37 ----
   * rewritten from SunOS 4.1 SID 1.18 89/10/06
   */
  /*
   * Copyright (c) 2012 by Delphix. All rights reserved.
   * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
+  * Copyright 2016 James S. Blachly, MD. All rights reserved.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <stdarg.h>
*** 1268,1278 ****
   */
  
  void
  do_format(void)
  {
!         char    header[SMALL_SCRATCH_BUFLEN];
          char    ch;
          char    iosz;
          const char    *fstr;
  
          disk_header[0] = 0;
--- 1269,1279 ----
   */
  
  void
  do_format(void)
  {
!         char    header[SMALL_SCRATCH_BUFLEN] = {0};
          char    ch;
          char    iosz;
          const char    *fstr;
  
          disk_header[0] = 0;
*** 1281,1292 ****
          if (do_disk & DISK_ERRORS) {
                  if (do_raw == 0) {
                          (void) sprintf(header, "s/w h/w trn tot ");
                  } else
                          (void) sprintf(header, "s/w,h/w,trn,tot");
!         } else
!                 *header = NULL;
          switch (do_disk & DISK_IO_MASK) {
                  case DISK_OLD:
                          if (do_raw == 0)
                                  fstr = "%cp%c tp%c serv  ";
                          else
--- 1282,1292 ----
          if (do_disk & DISK_ERRORS) {
                  if (do_raw == 0) {
                          (void) sprintf(header, "s/w h/w trn tot ");
                  } else
                          (void) sprintf(header, "s/w,h/w,trn,tot");
!         }
          switch (do_disk & DISK_IO_MASK) {
                  case DISK_OLD:
                          if (do_raw == 0)
                                  fstr = "%cp%c tp%c serv  ";
                          else
*** 1319,1330 ****
                                          /* with -r option */
                                          (void) snprintf(disk_header,
                                              sizeof (disk_header),
                                              "device,r/%c,w/%c,%cr/%c,%cw/%c,"
                                              "wait,actv,svc_t,%%%%w,"
!                                             "%%%%b,%s",
!                                             ch, ch, iosz, ch, iosz, ch, header);
                                  }
                          } else {
                                  /* with -n option */
                                  if (do_raw == 0) {
                                          fstr = "    r/%c    w/%c   %cr/%c   "
--- 1319,1337 ----
                                          /* with -r option */
                                          (void) snprintf(disk_header,
                                              sizeof (disk_header),
                                              "device,r/%c,w/%c,%cr/%c,%cw/%c,"
                                              "wait,actv,svc_t,%%%%w,"
!                                             "%%%%b%s%s",
!                                             ch, ch, iosz, ch, iosz, ch,
!                                             *header == '\0' ? "" : ",",
!                                             header);
!                                         /*
!                                          * if no -e flag, header == '\0...'
!                                          * Ternary operator above is to prevent
!                                          * trailing comma in full disk_header
!                                          */
                                  }
                          } else {
                                  /* with -n option */
                                  if (do_raw == 0) {
                                          fstr = "    r/%c    w/%c   %cr/%c   "
*** 1332,1341 ****
--- 1339,1360 ----
                                              "%%%%w  %%%%b %sdevice";
                                  } else {
                                          fstr = "r/%c,w/%c,%cr/%c,%cw/%c,"
                                              "wait,actv,wsvc_t,asvc_t,"
                                              "%%%%w,%%%%b,%sdevice";
+                                         /*
+                                          * if -rnxe, "tot" (from -e) and
+                                          * "device" are run together
+                                          * due to lack of trailing comma
+                                          * in 'header'. However, adding
+                                          * trailing comma to header at
+                                          * its definition leads to prob-
+                                          * lems elsewhere so it's added
+                                          * here in this edge case -rnxe
+                                          */
+                                         if (*header != '\0')
+                                                 (void) strcat(header, ",");
                                  }
                                  (void) snprintf(disk_header,
                                      sizeof (disk_header),
                                      fstr, ch, ch, iosz, ch, iosz,
                                      ch, header);