Add config path to settings including XDG_CONFIG_HOME usage

https://github.com/Hamlib/Hamlib/issues/985

src/rig.c

@@ -844,6 +844,7 @@ int HAMLIB_API rig_open(RIG *rig)
         strcpy(rs->dcdport.pathname, rs->dcdport_deprecated.pathname);
     }
 
+    rig_settings_load_all(NULL); // load default .hamlib_settings
     // Read in our settings
     char *cwd = malloc(4096);
 

src/settings.c

@@ -973,8 +973,38 @@ int HAMLIB_API rig_setting2idx(setting_t s)
 #endif
 
 
-#define SETTINGS_FILE ".hamlib_settings"
+#define SETTINGS_FILE "hamlib_settings"
-char *settings_file = SETTINGS_FILE;
+char settings_file[4096];
+
+HAMLIB_EXPORT(int) rig_settings_get_path(char *path, int pathlen)
+{
+    char cwd[4096];
+
+    if (getcwd(cwd, 4096) == NULL)
+    {
+        rig_debug(RIG_DEBUG_ERR, "%s: getcwd: %s\n", __func__, strerror(errno));
+        return -RIG_EINTERNAL;
+    }
+
+    char *xdgpath = getenv("XDG_CONFIG_HOME");
+    char *home = getenv("HOME");
+    snprintf(path, pathlen, "%s/.config", home);
+    if (xdgpath)
+    {
+        snprintf(path, pathlen-1, "%s/%s/%s", xdgpath, cwd, SETTINGS_FILE);
+    }
+    else if (home && access(path, F_OK) != -1)
+    {
+        snprintf(path, pathlen-1, "%s/.config/%s", home, SETTINGS_FILE);
+    }
+    else
+    {
+        // we add a leading period to hide the file
+        snprintf(path, pathlen-1, "%s/.%s", home, SETTINGS_FILE);
+    }
+    rig_debug(RIG_DEBUG_TRACE, "%s: path=%s\n", __func__, path);
+    return RIG_OK;
+}
 
 /**
  * \brief Save setting parameter
@@ -987,17 +1017,25 @@ char *settings_file = SETTINGS_FILE;
 HAMLIB_EXPORT(int) rig_settings_save(char *setting, void *value,
                                      settings_value_t valuetype)
 {
-    FILE *fp = fopen(settings_file, "r");
+    FILE *fp;
     FILE *fptmp;
+    char path[4096];
     char buf[4096];
     char *cvalue = (char *)value;
     int *ivalue = (int *)value;
+    int n=0;
     long *lvalue = (long *) value;
     float *fvalue = (float *) value;
     double *dvalue = (double *) value;
     char *vformat;
     char template[64];
 
+    rig_settings_get_path(path,sizeof(path));
+    fp = fopen(path, "r");
+    if (fp == NULL) {
+        rig_debug(RIG_DEBUG_WARN, "%s: %s not found\n", __func__,  path);
+        return -RIG_EIO;
+    }
     strcpy(template, "hamlib_settings_XXXXXX");
 
     switch (valuetype)
@@ -1057,6 +1095,10 @@ HAMLIB_EXPORT(int) rig_settings_save(char *setting, void *value,
     {
         char *tmp = strdup(buf);
         char *s = strtok(tmp, "=");
+        if (buf[0] == '#') {
+            fprintf(fptmp, "%s\n", buf);
+            continue;
+        }
 
         if (s == NULL)
         {
@@ -1066,6 +1108,7 @@ HAMLIB_EXPORT(int) rig_settings_save(char *setting, void *value,
             fclose(fptmp);
             return -RIG_EINTERNAL;
         }
+        ++n;
 
         char *v = strtok(NULL, "\r\n");
 
@@ -1077,7 +1120,7 @@ HAMLIB_EXPORT(int) rig_settings_save(char *setting, void *value,
             fclose(fptmp);
             return -RIG_EINTERNAL;
         }
-
+        rig_debug(RIG_DEBUG_TRACE, "%s: parsing setting %s=%s\n", __func__, s, v);
         fprintf(fptmp, vformat, s, value);
     }
 
@@ -1085,6 +1128,7 @@ HAMLIB_EXPORT(int) rig_settings_save(char *setting, void *value,
     fclose(fptmp);
     remove(settings_file);
     rename(template, settings_file);
+    rig_debug(RIG_DEBUG_TRACE, "%s: %d settings read\n", __func__, n);
     return -RIG_ENIMPL;
 }
 
@@ -1096,15 +1140,23 @@ HAMLIB_EXPORT(int) rig_settings_load(char *setting, void *value,
 
 HAMLIB_EXPORT(int) rig_settings_load_all(char *settings_file)
 {
-    FILE *fp = fopen(settings_file, "r");
+    FILE *fp;
     char buf[4096];
+    char settingstmp[4096];
 
+    if (settings_file == NULL) {
+        rig_settings_get_path(settingstmp, sizeof(settingstmp));
+        settings_file = settingstmp;
+    }
+
+    fp = fopen(settings_file, "r");
     if (fp == NULL)
     {
         rig_debug(RIG_DEBUG_ERR, "%s: settings_file error(%s): %s\n", __func__,
                   settings_file, strerror(errno));
         return -RIG_EINVAL;
     }
+    rig_debug(RIG_DEBUG_TRACE, "%s: opened %s\n", __func__, settings_file);
 
     while (fgets(buf, sizeof(buf), fp))
     {