Support 'config get' var pattern matching

commandline.c

@@ -1001,13 +1001,13 @@ int app_config_get(int argc, const char *const *argv, const struct command_line_
 {
   if (debug & DEBUG_VERBOSE) DEBUG_argv("command", argc, argv);
   const char *var;
-  if (cli_arg(argc, argv, o, "variable", &var, is_configvarname, NULL) == -1)
+  if (cli_arg(argc, argv, o, "variable", &var, is_configvarpattern, NULL) == -1)
     return -1;
   if (create_serval_instance_dir() == -1)
     return -1;
   if (cf_om_reload() == -1)
     return -1;
-  if (var) {
+  if (var && is_configvarname(var)) {
     const char *value = cf_om_get(cf_om_root, var);
     if (value) {
       cli_puts(var);
@@ -1018,6 +1018,8 @@ int app_config_get(int argc, const char *const *argv, const struct command_line_
   } else {
     struct cf_om_iterator it;
     for (cf_om_iter_start(&it, cf_om_root); it.node; cf_om_iter_next(&it)) {
+      if (var && cf_om_match(var, it.node) <= 0)
+	continue;
       if (it.node->text) {
 	cli_puts(it.node->fullkey);
 	cli_delim("=");

conf.h

@@ -232,6 +232,7 @@ struct cf_om_node {
 };
 
 int is_configvarname(const char *);
+int is_configvarpattern(const char *);
 int cf_om_parse(const char *source, const char *buf, size_t len, struct cf_om_node **rootp);
 int cf_om_get_child(const struct cf_om_node *parent, const char *key, const char *keyend);
 const char *cf_om_get(const struct cf_om_node *root, const char *fullkey);
@@ -239,6 +240,7 @@ int cf_om_set(struct cf_om_node **nodep, const char *fullkey, const char *text);
 int cf_om_add_child(struct cf_om_node **const parentp, const char *const key);
 void cf_om_free_node(struct cf_om_node **nodep);
 void cf_om_dump_node(const struct cf_om_node *node, int indent);
+int cf_om_match(const char *pattern, const struct cf_om_node *node);
 
 struct cf_om_iterator {
     const struct cf_om_node *node;

conf_om.c

@@ -44,8 +44,30 @@ static const char *cf_find_keyend(const char *const key, const char *const fullk
   return s;
 }
 
+static const char *cf_find_keypattern_end(const char *const key, const char *const fullkeyend)
+{
+  const char *s = cf_find_keyend(key, fullkeyend);
+  if (s == NULL) {
+    s = key;
+    if (s < fullkeyend && *s == '*')
+      ++s;
+    if (s + 1 == fullkeyend && *s == '*')
+      ++s;
+    if (s == key || (s < fullkeyend && *s != '.'))
+      return NULL;
+  }
+  return s;
+}
+
 /* This predicate function defines the constraints on configuration option names.
- * Valid:
+ *
+ *    OPTION_NAME  ::= ( KEY "." )* LASTKEY
+ *    KEY	   ::= ( ALPHA | "_") ( ALPHANUM | "_" )*
+ *    LASTKEY	   ::= KEY
+ *    ALPHA	   ::= "A" .. "Z" | "a" .. "z"
+ *    ALPHANUM	   ::= ALPHA | "0" .. "9"
+ *
+ * Valid examples:
  *	foo
  *	foo.bar
  *	foo.bar.chow
@@ -72,6 +94,25 @@ int is_configvarname(const char *text)
   return keyend != NULL;
 }
 
+/* This predicate function defines the constraints on configuration option patterns.
+ * Similar to is_configvarname().
+ *
+ *    OPTION_PATTERN	::= ( KEY_PATTERN "." )* LASTKEY_PATTERN
+ *    KEY_PATTERN	::= "*" | KEY
+ *    LASTKEY_PATTERN	::= "**" | KEY_PATTERN
+ *
+ *  @author Andrew Bettison <andrew@servalproject.com>
+ */
+int is_configvarpattern(const char *text)
+{
+  const char *const textend = text + strlen(text);
+  const char *key = text;
+  const char *keyend = NULL;
+  while (key <= textend && (keyend = cf_find_keypattern_end(key, textend)) != NULL)
+    key = keyend + 1;
+  return keyend != NULL;
+}
+
 static int cf_om_make_child(struct cf_om_node **const parentp, const char *const fullkey, const char *const key, const char *const keyend)
 {
   // Allocate parent node if it is not present.
@@ -253,6 +294,55 @@ void cf_om_dump_node(const struct cf_om_node *node, int indent)
   }
 }
 
+int cf_om_match(const char *pattern, const struct cf_om_node *node)
+{
+  if (node == NULL) {
+    //DEBUGF("pattern='%s' node=NULL", pattern);
+    return 0;
+  }
+  if (node->fullkey == NULL) {
+    //DEBUGF("pattern='%s' node->fullkey=NULL", pattern);
+    return 0;
+  }
+  /*
+  DEBUGF("pattern='%s' node->fullkey=%s node->nodc=%d node->text=%s",
+      pattern,
+      alloca_str_toprint(node->fullkey),
+      node->nodc,
+      alloca_str_toprint(node->text)
+    );
+  */
+  if (!pattern[0])
+    return -1;
+  const char *const pattern_end = pattern + strlen(pattern);
+  const char *pat = pattern;
+  const char *key = node->fullkey;
+  const char *const fullkeyend = node->fullkey + strlen(node->fullkey);
+  const char *keyend = NULL;
+  const char *patend = pat;
+  //DEBUGF("   pat=%s key=%s", alloca_str_toprint(pat), alloca_str_toprint(key));
+  while (pat < pattern_end && key <= fullkeyend && (keyend = cf_find_keyend(key, fullkeyend)) && (patend = cf_find_keypattern_end(pat, pattern_end))) {
+    if (pat[0] == '*') {
+      if (pat[1] == '*')
+	return 1;
+      pat = patend;
+      key = keyend;
+    } else {
+      while (pat < patend && key < fullkeyend && *pat == *key)
+	++pat, ++key;
+      if (pat != patend || key != keyend)
+	return 0;
+    }
+    if (*pat)
+      ++pat;
+    if (*key)
+      ++key;
+    //DEBUGF("   pat=%s key=%s", alloca_str_toprint(pat), alloca_str_toprint(key));
+  }
+  //DEBUGF("   patend=%s keyend=%s", alloca_str_toprint(patend), alloca_str_toprint(keyend));
+  return patend == NULL ? -1 : keyend && keyend == fullkeyend && pat == pattern_end;
+}
+
 const char *cf_om_get(const struct cf_om_node *node, const char *fullkey)
 {
   if (node == NULL)