http://jackxiang.com/index.php zh-cn http://jackxiang.com/post// jack <xdy108@126.com> Fri, 19 Sep 2008 09:08:50 +0000 http://jackxiang.com/post// 查找目录：find /（查找范围） -name '查找关键字' -type d
查找文件：find /（查找范围） -name 查找关键字 -print
最后通过：
find . -name "*.jpg" &#124; xargs rm -Rf
find . -name "*bak_jack*"|xargs rm -Rf
完全解决！
find ./ -size 2265c &#124; xargs rm 按指定大小删除
如想删除/tmp/xdebug下面所有的文件，用下面方法，一定要加type f，不加会把目录也删除了滴:
#!/bin/bash find /tmp/xdebug -name "*" -type f|xargs rm -Rf dateTime=`date +%Y%m%d%H%M%S` echo $dateTime

以下来自：http://www.uini.net/?p=1985
Linux技巧：一次删除一百万个文件的最快方法---rsync –delete将目标文件夹以一个空文件夹来替换。
最初的测评
昨天，我看到一个非常有趣的删除一个目录下的海量文件的方法。这个方法来自http://www.quora.com/How-can-someone-rapidly-delete-400-000-files里的Zhenyu Lee。

他没有使用find 或 xargs，他很有创意的利用了rsync的强大功能，使用rsync –delete将目标文件夹以一个空文件夹来替换。之后，我做了一个实验来比较各种方法。让我吃惊的是，Lee的方法要比其它的快的多。下面就是我的测评。

环境：

    CPU: Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz
    MEM: 4G
    HD: ST3250318AS: 250G/7200RPM

Method   # Of Files   Deletion Time
rsync -a –delete empty/ s1/   1000000   6m50.638s
find s2/ -type f -delete   1000000   87m38.826s
find s3/ -type f | xargs -L 100 rm   1000000   83m36.851s
find s4/ -type f | xargs -L 100 -P 100 rm   1000000   78m4.658s
rm -rf s5   1000000   80m33.434s

使用 –delete 和 –exclude，你可以选择性删除符合条件的文件。还有一点，当你需要保留这个目录做其它用处时，这种方法是再适合不过了。
重新测评

几天前，Keith-Winstein在回复Quora上的这个帖子时说我之前的测评无法复制，因为操作的时间持续的太久。我澄清一下，这些数据过大，可能是因为我的计算机在过去的几年里做的事太多，测评中可能存在一些文件系统错误。但我不确定是这些原因。现在好了，我弄了一天比较新的计算机，把测评再做一次。这次我使用/usr/bin/time，它能提供更详细的信息。下面就是新的结果。

(每次都是1000000个文件。每个文件的体积都是0。)
Command   Elapsed   System Time   %CPU   cs (Vol/Invol)
rsync -a –delete empty/ a   10.60   1.31   95   106/22
find b/ -type f -delete   28.51   14.46   52   14849/11
find c/ -type f | xargs -L 100 rm   41.69   20.60   54   37048/15074
find d/ -type f | xargs -L 100 -P 100 rm   34.32   27.82   89   929897/21720
rm -rf f   31.29   14.80   47   15134/11
原始输出

# method 1
~/test $ /usr/bin/time -v  rsync -a --delete empty/ a/
        Command being timed: "rsync -a --delete empty/ a/"
        User time (seconds): 1.31
        System time (seconds): 10.60
        Percent of CPU this job got: 95%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:12.42
        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): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 24378
        Voluntary context switches: 106
        Involuntary context switches: 22
        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

# method 2
        Command being timed: "find b/ -type f -delete"
        User time (seconds): 0.41
        System time (seconds): 14.46
        Percent of CPU this job got: 52%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:28.51
        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): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 11749
        Voluntary context switches: 14849
        Involuntary context switches: 11
        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
# method 3
find c/ -type f | xargs -L 100 rm
~/test $ /usr/bin/time -v ./delete.sh
        Command being timed: "./delete.sh"
        User time (seconds): 2.06
        System time (seconds): 20.60
        Percent of CPU this job got: 54%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:41.69
        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): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 1764225
        Voluntary context switches: 37048
        Involuntary context switches: 15074
        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

# method 4
find d/ -type f | xargs -L 100 -P 100 rm
~/test $ /usr/bin/time -v ./delete.sh
        Command being timed: "./delete.sh"
        User time (seconds): 2.86
        System time (seconds): 27.82
        Percent of CPU this job got: 89%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:34.32
        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): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 1764278
        Voluntary context switches: 929897
        Involuntary context switches: 21720
        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

# method 5
~/test $ /usr/bin/time -v rm -rf f
        Command being timed: "rm -rf f"
        User time (seconds): 0.20
        System time (seconds): 14.80
        Percent of CPU this job got: 47%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 0:31.29
        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): 0
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 0
        Minor (reclaiming a frame) page faults: 176
        Voluntary context switches: 15134
        Involuntary context switches: 11
        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

我真的十分好奇为什么Lee的方法要比其它的快，竟然比rm -rf也要快。如果有人知道，请写在下面，非常感谢。 ]]> http://jackxiang.com/post//#blogcomment <user@domain.com> Thu, 01 Jan 1970 00:00:00 +0000 http://jackxiang.com/post//#blogcomment