void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
void exec_command_append_list(ExecCommand **l, ExecCommand *e);
int exec_command_set(ExecCommand *c, const char *path, ...);
+int exec_command_append(ExecCommand *c, const char *path, ...);
void exec_context_init(ExecContext *c);
void exec_context_done(ExecContext *c);