ADD: added the "hf snoop" patch original from @Enio, rearranged by @Etmatrix.

ADD:  added the "t55x7" refactoring by @marshmellow42

client/cmdhf.c

@@ -736,6 +736,14 @@ int CmdHFSearch(const char *Cmd){
 	return 0;
 }
 
+int CmdHFSnoop(const char *Cmd)
+{
+	char * pEnd;
+	UsbCommand c = {CMD_HF_SNIFFER, {strtol(Cmd, &pEnd,0),strtol(pEnd, &pEnd,0),0}};
+	SendCommand(&c);
+	return 0;
+}
+
 static command_t CommandTable[] = 
 {
   {"help",        CmdHelp,          1, "This help"},
@@ -752,6 +760,7 @@ static command_t CommandTable[] =
   {"tune",			CmdHFTune,      0, "Continuously measure HF antenna tuning"},
   {"list",        CmdHFList,        1, "List protocol data in trace buffer"},
   {"search",      CmdHFSearch,      1, "Search for known HF tags [preliminary]"},
+  {"snoop",       CmdHFSnoop,       0, "<samples to skip (10000)> <triggers to skip (1)> Generic LF/HF Snoop in Testing stage"},
 	{NULL, NULL, 0, NULL}
 };