-int run_command_v(const char **argv);
-int run_command_opt(int opt, const char *cmd, ...);
-int run_command(const char *cmd, ...);
+int run_command_v_opt_cd(const char **argv, int opt, const char *dir);
+
+/*
+ * env (the environment) is to be formatted like environ: "VAR=VALUE".
+ * To unset an environment variable use just "VAR".
+ */
+int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);