• Linux学习记录(三):time 相关


    time 不仅仅可以统计时间,还可以反映CPU、内存情况等。

    一、time

    格式  : time [options] [commands] [arguments]

    time ls
     

    real    0m0.016s   <== 实际使用时间(real time)

    user    0m0.001s    <== 用户态使用时间(the process spent in user mode)

    sys     0m0.002s   <== 内核态使用时间(the process spent in kernel mode)

    time命令跟上-p参数可以只打印时间数值(秒数),不打印单位。

    如 

    time –p ls

    real 0.01
    user 0.00
    sys 0.00

    二、更为强大的外部命令     /usr/bin/time

    其实:

    [root@v01 ~]# type -a time
    time is a shell keyword
    time is /usr/bin/time

    time 是/usr/bin/time 一个简单执行

    /usr/bin/time 用法

    [root@v01 ~]# /usr/bin/time
    Usage: /usr/bin/time [-apvV] [-f format] [-o file] [--append] [--verbose]
           [--portability] [--format=format] [--output=file] [--version]
           [--help] command [arg...]

    /usr/bin/time ls

    0.00user 0.00system 0:00.01elapsed 10%CPU (0avgtext+0avgdata 4080maxresident)k
    0inputs+0outputs (0major+294minor)pagefaults 0swaps

    很强大有没有啊,再来一发

    /usr/bin/time –v  ls

    Command being timed: "ls"
            User time (seconds): 0.00
            System time (seconds): 0.00
            Percent of CPU this job got: 10%
            Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.01
            Average shared text size (kbytes): 0
            Average unshared data size (kbytes): 0
            Average stack size (kbytes): 0
            Average total size (kbytes): 0
            Maximum resident set size (kbytes): 4096
            Average resident set size (kbytes): 0
            Major (requiring I/O) page faults: 0
            Minor (reclaiming a frame) page faults: 298
            Voluntary context switches: 1
            Involuntary context switches: 8
            Swaps: 0
            File system inputs: 0
            File system outputs: 0
            Socket messages sent: 0
            Socket messages received: 0
            Signals delivered: 0
            Page size (bytes): 4096
            Exit status: 0

    重定向到文件   注意格式

    { time command-line; } 2>file

    ( time command-line ) 2>file

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  • 原文地址:https://www.cnblogs.com/xinqi/p/4914965.html
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