--- plutins/check_http.c	2002-10-28 18:02:11.000000000 +0100
+++ plugins/check_http.c	2002-10-28 19:42:30.000000000 +0100
@@ -44,7 +44,7 @@
 \(-H <vhost> | -I <IP-address>) [-u <uri>] [-p <port>]\n\
             [-w <warn time>] [-c <critical time>] [-t <timeout>] [-L]\n\
             [-a auth] [-f <ok | warn | critcal | follow>] [-e <expect>]\n\
-            [-s string] [-r <regex> | -R <case-insensitive regex>]\n\
+            [-s string] [-r <regex> | -R <case-insensitive regex>] [-x]\n\
             [-P string]"
 
 #define LONGOPTIONS "\
@@ -71,6 +71,8 @@
    Seconds before connection times out (default: %d)\n\
  -a, --authorization=AUTH_PAIR\n\
    Username:password on sites with basic authentication\n\
+ -x, --reverse\n\
+   Reverse the result of -r|-R|-s (like grep -v)\n\
  -L, --link=URL\n\
    Wrap output in HTML link (obsoleted by urlize)\n\
  -f, --onredirect=<ok|warning|critical|follow>\n\
@@ -190,6 +192,7 @@
 int server_expect_yn = 0;
 char server_expect[MAX_INPUT_BUFFER] = HTTP_EXPECT;
 char string_expect[MAX_INPUT_BUFFER] = "";
+int found_reverse = FALSE;	/* grep -v */
 double warning_time = 0;
 int check_warning_time = FALSE;
 double critical_time = 0;
@@ -287,6 +290,7 @@
 		{"regex", required_argument, 0, 'r'},
 		{"ereg", required_argument, 0, 'r'},
 		{"eregi", required_argument, 0, 'R'},
+		{"reverse", no_argument, 0, 'x'},
 		{"onredirect", required_argument, 0, 'f'},
 		{"certificate", required_argument, 0, 'C'},
 		{0, 0, 0, 0}
@@ -309,7 +313,7 @@
 			strcpy (argv[c], "-n");
 	}
 
-#define OPTCHARS "Vvht:c:w:H:P:I:a:e:p:s:R:r:u:f:C:nLS"
+#define OPTCHARS "Vvht:c:w:H:P:I:a:e:p:s:R:r:u:f:C:nLSx"
 
 	while (1) {
 #ifdef HAVE_GETOPT_H
@@ -442,6 +446,9 @@
 			usage ("check_http: call for regex which was not a compiled option\n");
 #endif
 			break;
+		case 'x':	/* grep -v */
+			found_reverse = TRUE;
+			break;
 		case 'v': /* verbose */
 			verbose = TRUE;
 			break;
@@ -849,31 +856,69 @@
 
 	if (strlen (string_expect)) {
 		if (strstr (page, string_expect)) {
-			printf ("HTTP ok: %s - %7.3f second response time %s%s|time=%7.3f\n",
-			        status_line, elapsed_time,
-			        timestamp, (display_html ? "</A>" : ""), elapsed_time);
-			exit (STATE_OK);
+			if (found_reverse) { /* grep -v */
+				printf ("HTTP CRITICAL: string found%s|time=%7.3f\n",
+					(display_html ? "</A>" : ""),
+					elapsed_time);
+				exit (STATE_CRITICAL) ;
+			} else {
+				printf ("HTTP ok: %s - %7.3f second response time %s%s|time=%7.3f\n",
+					status_line, elapsed_time,
+					timestamp,
+					(display_html ? "</A>" : ""),
+					elapsed_time);
+				exit (STATE_OK);
+			}
 		}
-		else {
-			printf ("HTTP CRITICAL: string not found%s|time=%7.3f\n",
-			        (display_html ? "</A>" : ""), elapsed_time);
-			exit (STATE_CRITICAL);
+		else {		/* not found */
+			if (found_reverse) { /* grep -v */ 
+				printf ("HTTP ok: %s - %7.3f second response time %s%s|time=%7.3f\n",
+					status_line, elapsed_time,
+					timestamp, 
+					(display_html ? "</A>" : ""),
+					elapsed_time);
+				exit (STATE_OK) ;
+			} else {
+				printf ("HTTP CRITICAL: string not found%s|time=%7.3f\n",
+					(display_html ? "</A>" : ""), elapsed_time);
+				exit (STATE_CRITICAL);
+			}
 		}
 	}
 #ifdef HAVE_REGEX_H
 	if (strlen (regexp)) {
 		errcode = regexec (&preg, page, REGS, pmatch, 0);
 		if (errcode == 0) {
-			printf ("HTTP ok: %s - %7.3f second response time %s%s|time=%7.3f\n",
-			        status_line, elapsed_time,
-			        timestamp, (display_html ? "</A>" : ""), elapsed_time);
-			exit (STATE_OK);
+			if (found_reverse) { /* grep -v */
+				printf ("HTTP CRITICAL: pattern found%s|time=%7.3f\n",
+					(display_html ? "</A>" : ""),
+					elapsed_time);
+				exit (STATE_CRITICAL);
+			} else {
+				printf ("HTTP ok: %s - %7.3f second response time %s%s|time=%7.3f\n",
+					status_line, elapsed_time,
+					timestamp, 
+					(display_html ? "</A>" : ""),
+					elapsed_time);
+				exit (STATE_OK);
+			}
 		}
 		else {
 			if (errcode == REG_NOMATCH) {
-				printf ("HTTP CRITICAL: pattern not found%s|time=%7.3f\n",
-				        (display_html ? "</A>" : ""), elapsed_time);
-				exit (STATE_CRITICAL);
+				if (found_reverse) { /* grep -v */
+					printf ("HTTP ok: %s - %7.3f second response time %s%s|time=%7.3f\n",
+						status_line, elapsed_time,
+						timestamp, 
+						(display_html ? "</A>" : ""),
+						elapsed_time);
+					exit (STATE_OK);
+
+				} else {
+					printf ("HTTP CRITICAL: pattern not found%s|time=%7.3f\n",
+						(display_html ? "</A>" : ""),
+						elapsed_time);
+					exit (STATE_CRITICAL);
+				}
 			}
 			else {
 				regerror (errcode, &preg, errbuf, MAX_INPUT_BUFFER);