Block and character devices(块或字符设备) Block devices include disk drives(块设备包括磁盘) Commands include read. write, seek (命令包括读,写,搜寻) Raw lo or file-system access (原始的O或文件系统存取) Memory-mapped file access possible (存储器映射文件访问的可能性) Character devices include keyboards, mice, serial ports (字符设备包括键盘,鼠标和串口设备) Commands include get,put(命令有 get, put) Libraries layered on top allow line editing (顶层的函数库允许行编辑) Applied Operating System Concepts 12 Silberschatz, Galvin, and Gagne @199912.9 Silberschatz, Galvin, and Gagne ©1999 Applied Operating System Concepts Block and Character Devices（块或字符设备） • Block devices include disk drives（块设备包括磁盘） – Commands include read, write, seek （命令包括读，写，搜寻） – Raw I/O or file-system access （原始的I/O或文件系统存取） – Memory-mapped file access possible （存储器映射文件访问的可能性） • Character devices include keyboards, mice, serial ports （字符设备包括键盘，鼠标和串口设备） – Commands include get, put（命令有get,put) – Libraries layered on top allow line editing （顶层的函数库允许行编辑）