added nosave parameter to lf em 4x05 dump

CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+ - Changed `lf em 4x05 dump` - now supports the `--ns` nosave parameter (@iceman1001)
  - Added new command `data bmap` - breaks down a hexvalue to a binary template (@iceman1001)
  - Changed aid_desfire.json - added entreis from the Metrodroid project (@iceman1001)
  - Changed mad.json - added entries from the Metrodroid project (@iceman1001)

client/src/cmdlfem4x05.c

@@ -514,6 +514,7 @@ int CmdEM4x05Dump(const char *Cmd) {
         arg_param_begin,
         arg_str0("p", "pwd", "<hex>", "password (00000000)"),
         arg_str0("f", "file", "<fn>", "override filename prefix (optional).  Default is based on UID"),
+        arg_lit0(NULL, "ns", "no save to file"),
         arg_param_end
     };
     CLIExecWithReturn(ctx, Cmd, argtable, true);
@@ -522,6 +523,7 @@ int CmdEM4x05Dump(const char *Cmd) {
     int fnlen = 0;
     char filename[FILE_PATH_SIZE] = {0};
     CLIParamStrToBuf(arg_get_str(ctx, 2), (uint8_t *)filename, FILE_PATH_SIZE, &fnlen);
+    bool nosave = arg_get_lit(ctx, 3);
     CLIParserFree(ctx);
 
     uint8_t addr = 0;
@@ -693,6 +695,13 @@ int CmdEM4x05Dump(const char *Cmd) {
     } else {
     }
 
+    if (nosave) {
+        PrintAndLogEx(NORMAL, "");
+        PrintAndLogEx(INFO, "Called with no save option");
+        PrintAndLogEx(NORMAL, "");
+        return PM3_SUCCESS;
+    }
+
     // all ok save dump to file
     if (success == PM3_SUCCESS) {