PRN在Windows上是一个特殊的文件名,它表示并口设备。Windows中的其他保留文件名还有:
CON : Keyboard and display
PRN : System list device, usually a parallel port
AUX : Auxiliary device, usually a serial port
CLOCK$ : System real-time clock
NUL: Bit-bucket device
A:-Z: : Drive letters
COM1 : First serial communications port
LPT1 : First parallel printer port
LPT2 : Second parallel printer port
LPT3 : Third parallel printer port
COM2 : Second serial communications port
COM3 : Third serial communications port
COM4 : Fourth serial communications port
这是MS-DOS就开始有的历史遗留问题,直到现在的Windows 10仍然受其影响。Unix系统不受此限制。