2 files changed, 49 insertions, 2 deletions

diff --git a/docs/idevicesyslog.1 b/docs/idevicesyslog.1
index 66ae2e4..ae4aff2 100644
--- a/docs/idevicesyslog.1
+++ b/docs/idevicesyslog.1
@@ -44,6 +44,11 @@ Force writing colored output, e.g. when using \f[B]\-\-output\f[].
 .B \-m, \-\-match STRING
 only print messages that contain STRING
 
+.SH FILTER OPTIONS
+.TP
+.B \-M, \-\-unmatch STRING
+print messages that not contain STRING
+
 This option will set a filter to only printed log messages that contain the given string.
 .TP
 .B \-t, \-\-trigger STRING
diff --git a/tools/idevicesyslog.c b/tools/idevicesyslog.c
index dbd7b01..f185f3a 100644
--- a/tools/idevicesyslog.c
+++ b/tools/idevicesyslog.c
@@ -58,6 +58,9 @@ static int num_pid_filters = 0;
 static char** msg_filters = NULL;
 static int num_msg_filters = 0;
 
+static char** msg_reverse_filters = NULL;
+static int num_msg_reverse_filters = 0;
+
 static char** trigger_filters = NULL;
 static int num_trigger_filters = 0;
 static char** untrigger_filters = NULL;
@@ -217,6 +220,21 @@ static void syslog_callback(char c, void *user_data)
                                         }
                                         shall_print = 1;
                                 }
+                                if (num_msg_reverse_filters > 0) {
+                                        int found = 0;
+                                        int i;
+                                        for (i = 0; i < num_msg_reverse_filters; i++) {
+                                                if (strstr(device_name_end+1, msg_reverse_filters[i])) {
+                                                        found = 1;
+                                                        break;
+                                                }
+                                        }
+                                        if (found) {
+                                                shall_print = 0;
+                                                break;
+                                        }
+                                        shall_print = 1;
+                                }
 
                                 /* process name */
                                 char* proc_name_start = p;
@@ -331,7 +349,7 @@ static void syslog_callback(char c, void *user_data)
                         }
                 } while (0);
 
-                if ((num_msg_filters == 0 && num_proc_filters == 0 && num_pid_filters == 0 && num_trigger_filters == 0 && num_untrigger_filters == 0) || shall_print) {
+                if ((num_msg_filters == 0 && num_msg_reverse_filters == 0 && num_proc_filters == 0 && num_pid_filters == 0 && num_trigger_filters == 0 && num_untrigger_filters == 0) || shall_print) {
                         fwrite(linep, 1, lp, stdout);
                         cprintf(COLOR_RESET);
                         fflush(stdout);
@@ -487,6 +505,7 @@ static void print_usage(int argc, char **argv, int is_error)
                 "\n"
                 "FILTER OPTIONS:\n"
                 "  -m, --match STRING      only print messages that contain STRING\n"
+                "  -M, --unmatch STRING    print messages that not contain STRING\n"
                 "  -t, --trigger STRING    start logging when matching STRING\n"
                 "  -T, --untrigger STRING  stop logging when matching STRING\n"
                 "  -p, --process PROCESS   only print messages from matching process(es)\n"
@@ -542,7 +561,7 @@ int main(int argc, char *argv[])
         signal(SIGPIPE, SIG_IGN);
 #endif
 
-        while ((c = getopt_long(argc, argv, "dhu:nxt:T:m:e:p:qkKo:v", longopts, NULL)) != -1) {
+        while ((c = getopt_long(argc, argv, "dhu:nxt:T:m:M:e:p:qkKo:v", longopts, NULL)) != -1) {
                 switch (c) {
                 case 'd':
                         idevice_set_debug_level(1);
@@ -593,6 +612,22 @@ int main(int argc, char *argv[])
                                 num_msg_filters++;
                         }
                         break;
+                case 'M':
+                        if (!*optarg) {
+                                fprintf(stderr, "ERROR: reverse message filter string must not be empty!\n");
+                                print_usage(argc, argv, 1);
+                                return 2;
+                        } else {
+                                char **new_msg_filters = realloc(msg_reverse_filters, sizeof(char*) * (num_msg_reverse_filters+1));
+                                if (!new_msg_filters) {
+                                        fprintf(stderr, "ERROR: realloc() failed\n");
+                                        exit(EXIT_FAILURE);
+                                }
+                                msg_reverse_filters = new_msg_filters;
+                                msg_reverse_filters[num_msg_reverse_filters] = strdup(optarg);
+                                num_msg_reverse_filters++;
+                        }
+                        break;
                 case 't':
                         if (!*optarg) {
                                 fprintf(stderr, "ERROR: trigger filter string must not be empty!\n");
@@ -761,6 +796,13 @@ int main(int argc, char *argv[])
                 }
                 free(msg_filters);
         }
+        if (num_msg_reverse_filters > 0) {
+                int i;
+                for (i = 0; i < num_msg_reverse_filters; i++) {
+                        free(msg_reverse_filters[i]);
+                }
+                free(msg_reverse_filters);
+        }
         if (num_trigger_filters > 0) {
                 int i;
                 for (i = 0; i < num_trigger_filters; i++) {