TOP是一个动态显示过程,即可以通过用户按键来不断刷新当前状态.如果在前台执行该命令,它将独占前台,直到用户终止该程序为止.比较准确的说,top命令提供了实时的对系统处理器的状态监视.它将显示系统中CPU最“敏感”的任务列表.该命令可以按CPU使用.内存使用和执行时间对任务进行排序；而且该命令的很多特性都可以通过交互式命令或者在个人定制文件中进行设定.

top - 12:38:33 up 50 days, 23:15,??7 users,??load average: 60.58, 61.14, 61.22

Tasks: 203 total,??60 running, 139 sleeping,???4 stopped,???0 zombie

Cpu(s)??: 27.0%us, 73.0%sy,??0.0%ni,??0.0%id,??0.0%wa,??0.0%hi,??0.0%si,??0.0%st

Mem:???1939780k total,??1375280k used,???564500k free,???109680k buffers

Swap:??4401800k total,???497456k used,??3904344k free,???848712k cached

PID USER??????PR??NI??VIRT??RES??SHR S %CPU %MEM????TIME+??COMMAND????????????????????????????????

?4338 oracle????25???0??627m 209m 207m R????0 11.0 297:14.76 oracle????????????????????????????????

?4267 oracle????25???0??626m 144m 143m R????6??7.6??89:16.62 oracle????????????????????????????????

?3458 oracle????25???0??672m 133m 124m R????0??7.1???1283:08 oracle????????????????????????????????

?3478 oracle????25???0??672m 124m 115m R????0??6.6???1272:30 oracle????????????????????????????????

?3395 oracle????25???0??672m 122m 113m R????0??6.5???1270:03 oracle?????????????????????????????????

?3480 oracle????25???0??672m 122m 109m R????8??6.4???1274:13 oracle????????????????????????????????

?3399 oracle????25???0??672m 121m 110m R????0??6.4???1279:37 oracle????????????????????????????????

?4261 oracle????25???0??634m 100m??99m R????0??5.3??86:13.90 oracle????????????????????????????????

25737 oracle????25???0??632m??81m??74m R????0??4.3 272:35.42 oracle????????????????????????????????

?7072 oracle????25???0??626m??72m??71m R????0??3.8???6:35.68 oracle????????????????????????????????

16073 oracle????25???0??630m??68m??63m R????8??3.6 175:20.36 oracle????????????????????????????????

16140 oracle????25???0??630m??66m??60m R????0??3.5 175:13.42 oracle????????????????????????????????

16122 oracle????25???0??630m??66m??60m R????0??3.5 176:47.73 oracle????????????????????????????????

??786 oracle????25???0??627m??63m??63m R????0??3.4???1:54.93 oracle????????????????????????????????

?4271 oracle????25???0??627m??59m??58m R????8??3.1??86:09.64 oracle????????????????????????????????