add option --json to pref show

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 `pref show` - add option to dump as JSON (@doegox)
 - Changed `mf_backdoor_dump.py`- use faster ecfill/eview (@doegox)
 - Changed `hf mf ecfill` - wait for execution and return status (@doegox)
 - Changed `hf 14a reader` - added option to wait for a card (@doegox)

client/src/fileutils.c

@@ -818,6 +818,17 @@ int saveFileJSONrootEx(const char *preferredName, const void *root, size_t flags
     return PM3_EFILE;
 }
 
+char *sprintJSON(JSONFileType ftype, uint8_t *data, size_t datalen, bool verbose, void (*callback)(json_t *)) {
+
+    json_t *root = json_object();
+    if (prepareJSON(root, ftype, data, datalen, verbose, callback) != PM3_SUCCESS) {
+        return NULL;
+    }
+    char *s = json_dumps(root, JSON_INDENT(2));
+    json_decref(root);
+    return s;
+}
+
 // wave file of trace,
 int saveFileWAVE(const char *preferredName, const int *data, size_t datalen) {
 

client/src/fileutils.h

@@ -142,6 +142,7 @@ int saveFileJSONex(const char *preferredName, JSONFileType ftype, uint8_t *data,
 int saveFileJSONroot(const char *preferredName, void *root, size_t flags, bool verbose);
 int saveFileJSONrootEx(const char *preferredName, const void *root, size_t flags, bool verbose, bool overwrite, savePaths_t e_save_path);
 int prepareJSON(json_t *root, JSONFileType ftype, uint8_t *data, size_t datalen, bool verbose, void (*callback)(json_t *));
+char *sprintJSON(JSONFileType ftype, uint8_t *data, size_t datalen, bool verbose, void (*callback)(json_t *));
 /** STUB
  * @brief Utility function to save WAVE data to a file. This method takes a preferred name, but if that
  * file already exists, it tries with another name until it finds something suitable.

client/src/preferences.c

@@ -168,6 +168,16 @@ int preferences_save(void) {
     return PM3_SUCCESS;
 }
 
+// Dump all settings from memory (struct) to console in JSON
+int preferences_dump(void) {
+    uint8_t dummyData = 0x00;
+    size_t dummyDL = 0x01;
+    char *s = sprintJSON(jsfCustom, &dummyData, dummyDL, true, &preferences_save_callback);
+    PrintAndLogEx(NORMAL, "%s", s);
+    free(s);
+    return PM3_SUCCESS;
+}
+
 void preferences_save_callback(json_t *root) {
 
     JsonSaveStr(root, "FileType", "settings");
@@ -1393,11 +1403,18 @@ static int CmdPrefShow(const char *Cmd) {
                  );
     void *argtable[] = {
         arg_param_begin,
+        arg_lit0("j", "json", "Dump prefs as JSON"),
         arg_param_end
     };
+
     CLIExecWithReturn(ctx, Cmd, argtable, true);
+    bool json_dump = arg_get_lit(ctx, 1);
     CLIParserFree(ctx);
 
+    if (json_dump) {
+        preferences_dump();
+        return PM3_SUCCESS;
+    }
     if (g_session.preferences_loaded) {
         char *fn = prefGetFilename();
         PrintAndLogEx(NORMAL, "");

client/src/preferences.h

@@ -27,6 +27,7 @@
 int CmdPreferences(const char *Cmd);
 int preferences_load(void);
 int preferences_save(void);
+int preferences_dump(void);
 
 void preferences_save_callback(json_t *root);
 void preferences_load_callback(json_t *root);