基于IFS文件过滤驱动开发，工作在系统核心层，与杀毒软件、防火墙软件完全兼容-IFS file system filter driver-based development work in the system, the core layer, and antivirus software, firewall software is fully compatible

Ifcount keeps track of the number of ifs and ends. Each time an if is encountered Ifcount is incremented and each time an end is encountered it is decremented.

strip leading IFS characters.