feat: Add basename support

Now, the user can decide to show only the program name, instead of the
full program path. It is useful, when you have a very long hierarchy of
directories, which, with the full path name, the user might not see the
program name.

src/main.cpp

@@ -27,7 +27,7 @@ static void help(bool iserror) {
   // output << "usage: nethogs [-V] [-b] [-d seconds] [-t] [-p] [-f (eth|ppp))]
   // [device [device [device ...]]]\n";
   output << "usage: nethogs [-V] [-h] [-x] [-d seconds] [-v mode] [-c count] "
-            "[-t] [-p] [-s] [-a] [-l] [-f filter] [-C]"
+            "[-t] [-p] [-s] [-a] [-l] [-f filter] [-C] [-b]"
             "[device [device [device ...]]]\n";
   output << "		-V : prints version.\n";
   output << "		-h : prints this help.\n";
@@ -48,6 +48,7 @@ static void help(bool iserror) {
   output << "		-C : capture TCP and UDP.\n";
   output << "		-g : garbage collection period in number of refresh. "
             "default is 50.\n";
+  output << "		-b : Short program name. Displays only the program name.\n";
   output << "		-f : EXPERIMENTAL: specify string pcap filter (like "
             "tcpdump)."
             " This may be removed or changed in a future version.\n";
@@ -59,6 +60,7 @@ static void help(bool iserror) {
   output << " s: sort by SENT traffic\n";
   output << " r: sort by RECEIVED traffic\n";
   output << " l: display command line\n";
+  output << " b: display the program basename instead of the fullpath\n";
   output << " m: switch between total (KB, B, MB) and throughput (KB/s, MB/s, "
             "GB/s) mode\n";
 }
@@ -145,7 +147,7 @@ int main(int argc, char **argv) {
   int garbage_collection_period = 50;
 
   int opt;
-  while ((opt = getopt(argc, argv, "Vhxtpsd:v:c:laf:Cg:")) != -1) {
+  while ((opt = getopt(argc, argv, "Vhxtpsd:v:c:laf:Cbg:")) != -1) {
     switch (opt) {
     case 'V':
       versiondisplay();
@@ -187,6 +189,9 @@ int main(int argc, char **argv) {
     case 'C':
       catchall = true;
       break;
+    case 'b':
+      showBasename = true;
+      break;
     case 'g':
       garbage_collection_period = (time_t)atoi(optarg);
       break;