feat(expansion) 10291 expansion

src/utils/vars/vars.c

@@ -2,8 +2,11 @@
 #include "vars.h"
 
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
+#include <unistd.h>
 
 #include "../hash_map/hash_map.h"
 
@@ -14,6 +17,26 @@ struct hash_map *vars_init(void)
     return hash_map_init(VARS_INITIAL_SIZE);
 }
 
+void vars_default(struct hash_map *vars)
+{
+    set_var_copy(vars, "?", "0");
+    pid_t pid = getpid();
+    char pid_str[20];
+    snprintf(pid_str, sizeof(pid_str), "%d", pid);
+    set_var_copy(vars, "$$", pid_str);
+}
+
+short short_random(void)
+{
+    static bool seeded = false;
+    if (!seeded)
+    {
+        srand((unsigned)time(NULL));
+        seeded = true;
+    }
+    return (short)(rand() & 0x7FFF); // force 16 bits positive
+}
+
 char *get_var(const struct hash_map *vars, const char *key)
 {
     return (char *)hash_map_get(vars, key);

src/utils/vars/vars.h

@@ -10,6 +10,16 @@
  */
 struct hash_map *vars_init(void);
 
+/**
+ * Set default variables.
+ */
+void vars_default(struct hash_map *vars);
+
+/**
+ * Generate a random short integer (16 bits positive [0-32767]).
+ */
+short short_random(void);
+
 /**
  * Get the value of a variable, NULL if not found.
  */
@@ -26,7 +36,8 @@ char *get_var_or_env(const struct hash_map *vars, const char *key);
  * the hash_map and need to be on the heap. Returns true on success, false on
  * failure.
  */
-bool set_var(struct hash_map *vars, const char *key, const char *value);
+bool set_var(struct hash_map *vars, const char *key, const char *value,
+             bool *updated);
 
 /**
  * Same as set_var, but makes copies of key and value so you don't have to worry