JSON output

doc/nethogs.8

@@ -75,6 +75,9 @@ garbage collection period in number of refresh. default is 50.
 \fB-P\fP
 Show only processes with the specified pid(s).
 .TP
+\fB-j\fP
+Output in JSON format.
+.TP
 \fB-f\fP
 EXPERIMENTAL: specify string pcap filter (like tcpdump). This may be removed or changed in a future version.
 .TP

src/cui.cpp

@@ -49,6 +49,8 @@ extern int viewMode;
 extern bool showcommandline;
 extern bool showBasename;
 
+extern bool output_json;
+
 extern unsigned refreshlimit;
 extern unsigned refreshcount;
 
@@ -90,6 +92,7 @@ public:
 
   void show(int row, unsigned int proglen, unsigned int devlen);
   void log();
+  void json();
 
   double sent_value;
   double recv_value;
@@ -232,6 +235,48 @@ void Line::log() {
             << recv_value << std::endl;
 }
 
+#include <iomanip>
+
+std::string escape_json(const std::string &s) {
+    std::ostringstream o;
+    for (auto c = s.cbegin(); c != s.cend(); c++) {
+        switch (*c) {
+        case '"': o << "\\\""; break;
+        case '\\': o << "\\\\"; break;
+        case '\b': o << "\\b"; break;
+        case '\f': o << "\\f"; break;
+        case '\n': o << "\\n"; break;
+        case '\r': o << "\\r"; break;
+        case '\t': o << "\\t"; break;
+        default:
+            if ('\x00' <= *c && *c <= '\x1f') {
+                o << "\\u"
+                  << std::hex << std::setw(4) << std::setfill('0') << static_cast<int>(*c);
+            } else {
+                o << *c;
+            }
+        }
+    }
+    return o.str();
+}
+
+void Line::json() {
+  std::cout << "{";
+  std::cout << "\"name\": \"" << escape_json(m_name) << "\"";
+  std::cout << ", ";
+  std::cout << "\"pid\": \"" << m_pid << "\"";
+  std::cout << ", ";
+  std::cout << "\"uid\": \"" << m_uid << "\"";
+  std::cout << ", ";
+  std::cout << "\"devicename\": \"" << devicename << "\"";
+  std::cout << ", ";
+  std::cout << "\"sent\": " << sent_value;
+  std::cout << ", ";
+  std::cout << "\"recv\": " << recv_value;
+  std::cout << "}";
+}
+
+
 int get_devlen(Line *lines[], int nproc, int rows) {
   int devlen = MIN_COLUMN_WIDTH_DEV;
   int curlen;
@@ -343,6 +388,28 @@ void show_trace(Line *lines[], int nproc) {
   }
 }
 
+
+char* get_iso8601_timestamp() {
+    static char buffer[32];
+    time_t now = time(NULL);
+    struct tm *utc = gmtime(&now);
+    strftime(buffer, sizeof(buffer), "%Y-%m-%dT%H:%M:%SZ", utc);
+    return buffer;
+}
+
+void show_json(Line *lines[], int nproc) {
+  /* print them */
+  std::cout << "{\"timestamp\": \""<< get_iso8601_timestamp() << "\", \"processes\": [";
+  for (int i = 0; i < nproc; i++) {
+    if(i>0){
+      std::cout << ",";
+    }
+    lines[i]->json();
+    delete lines[i];
+  }
+  std::cout << "]}"<< std::endl;
+}
+
 void show_ncurses(Line *lines[], int nproc) {
   int rows;             // number of terminal rows
   int cols;             // number of terminal columns
@@ -453,7 +520,9 @@ void do_refresh() {
   /* sort the accumulated lines */
   qsort(lines, nproc, sizeof(Line *), GreatestFirst);
 
-  if (tracemode || DEBUG)
+  if (output_json)
+    show_json(lines, nproc);
+  else if (tracemode || DEBUG)
     show_trace(lines, nproc);
   else
     show_ncurses(lines, nproc);

src/main.cpp

@@ -69,6 +69,7 @@ static void help(bool iserror) {
   output << " b: display the program basename instead of the fullpath\n";
   output << " m: switch between total (kB, bytes, MB) and throughput (kB/s, "
             " MB/s, GB/s) mode\n";
+  output << " j: json output\n";
 }
 
 void quit_cb(int /* i */) {
@@ -80,7 +81,7 @@ void quit_cb(int /* i */) {
 }
 
 void forceExit(bool success, const char *msg, ...) {
-  if ((!tracemode) && (!DEBUG)) {
+  if ((!tracemode) && (!DEBUG) && (!output_json)) {
     exit_ui();
   }
 
@@ -141,7 +142,7 @@ void clean_up() {
   }
 
   procclean();
-  if ((!tracemode) && (!DEBUG))
+  if ((!tracemode) && (!DEBUG) && (!output_json))
     exit_ui();
 }
 
@@ -153,7 +154,7 @@ int main(int argc, char **argv) {
   int garbage_collection_period = 50;
 
   int opt;
-  while ((opt = getopt(argc, argv, "Vhxtpsd:v:c:laf:Cbg:P:")) != -1) {
+  while ((opt = getopt(argc, argv, "Vhxtpsd:v:c:laf:Cbg:P:j")) != -1) {
     switch (opt) {
     case 'V':
       versiondisplay();
@@ -204,6 +205,9 @@ int main(int argc, char **argv) {
     case 'P':
       pidsToWatch.insert((pid_t)atoi(optarg));
       break;
+    case 'j':
+      output_json = true;
+      break;
     default:
       help(true);
       exit(EXIT_FAILURE);
@@ -300,7 +304,7 @@ int main(int argc, char **argv) {
 
   struct dpargs *userdata = (dpargs *)malloc(sizeof(struct dpargs));
 
-  if ((!tracemode) && (!DEBUG)) {
+  if ((!tracemode) && (!DEBUG) && (!output_json)) {
     init_ui();
   }
 
@@ -328,7 +332,7 @@ int main(int argc, char **argv) {
     time_t const now = ::time(NULL);
     if (last_refresh_time + refreshdelay <= now) {
       last_refresh_time = now;
-      if ((!DEBUG) && (!tracemode)) {
+      if ((!DEBUG) && (!tracemode) && (!output_json)) {
         // handle user input
         ui_tick();
       }

src/nethogs.cpp

@@ -63,6 +63,7 @@ bool showcommandline = false;
 bool showBasename = false;
 // viewMode: kb/s or total
 int viewMode = VIEWMODE_KBPS;
+bool output_json = false;
 const char version[] = " version " VERSION;
 timeval curtime;