如何使用linux命令之--du

问题需求：查询指定目录下的所有文件夹的大小

思路：GOOGLE,BAIDU，常常忘记了MANUAL --help

1.

[root@racnode1 aiki]# du --help

Usage: du [OPTION]... [FILE]...

or: du [OPTION]... --files0-from=F

Summarize disk usage of each FILE, recursively for directories.

Mandatory arguments to long options are mandatory for short options too.

-a, --all write counts for all files, not just directories

--apparent-size print apparent sizes, rather than disk usage; although

the apparent size is usually smaller, it may be

larger due to holes in (`sparse') files, internal

fragmentation, indirect blocks, and the like

-B, --block-size=SIZE use SIZE-byte blocks

-b, --bytes equivalent to `--apparent-size --block-size=1'

-c, --total produce a grand total

-D, --dereference-args dereference FILEs that are symbolic links

--files0-from=F summarize disk usage of the NUL-terminated file

names specified in file F

-H like --si, but also evokes a warning; will soon

change to be equivalent to --dereference-args (-D)

-h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G)

--si like -h, but use powers of 1000 not 1024

-k like --block-size=1K

-l, --count-links count sizes many times if hard linked

-m like --block-size=1M

-L, --dereference dereference all symbolic links

-P, --no-dereference don't follow any symbolic links (this is the default)

-0, --null end each output line with 0 byte rather than newline

-S, --separate-dirs do not include size of subdirectories

-s, --summarize display only a total for each argument

-x, --one-file-system skip directories on different file systems

-X FILE, --exclude-from=FILE Exclude files that match any pattern in FILE.

--exclude=PATTERN Exclude files that match PATTERN.

--max-depth=N print the total for a directory (or file, with --all)

only if it is N or fewer levels below the command

line argument; --max-depth=0 is the same as

--summarize

--time show time of the last modification of any file in the

directory, or any of its subdirectories

--time=WORD show time as WORD instead of modification time:

atime, access, use, ctime or status

--time-style=STYLE show times using style STYLE:

full-iso, long-iso, iso, +FORMAT

FORMAT is interpreted like `date'

--help display this help and exit

--version output version information and exit

SIZE may be (or may be an integer optionally followed by) one of following:

kB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.

2.很多时候看是看不出个具体意思，简单做法做建相应目录文件，运行相关命令即可；

文章开头的需求，当我们敲入命令du --max-depth=1时

[root@racnode1 aiki]# du --max-depth=1

4 ./1

12 ./2

4 ./3

24

3.如果要进一步的详看子目录那么

[root@racnode1 aiki]# du -c

4 ./1

4 ./2/22

12 ./2

4 ./3

24 .

24 total

4.对于数字，如果你不知道单位是K，M时根据测试输入

[root@racnode1 aiki]# du --max-depth=1 -h

4.0K ./1

12K ./2

4.0K ./3

24K .

5.下面我们再回来看上面列举的3个参数

--max-depth=N print the total for a directory (or file, with --all)

only if it is N or fewer levels below the command

line argument; --max-depth=0 is the same as

--summarize

意思：输出一个目录的总大小（或者是文件，使用--all参数，也就是此命令也适用于文件)

仅它等于N或者是更低级别作为命令行参数时；--max-depth=0等同于--summarize

[root@racnode1 aiki]# du --max-depth=1 aa.txt

0 aa.txt

[root@racnode1 aiki]# du --summarize

24 .

------------------------------------------------------------------------------------------------------------------

-h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G)

-h也就是将格式转换为可读性强的格式，如果没有加很明显有时不知道单位是什么；

[root@racnode1 aiki]# du -h

4.0K ./1

4.0K ./2/22

12K ./2

4.0K ./3

24K .

[root@racnode1 aiki]# du --human-readable

4.0K ./1

4.0K ./2/22

12K ./2

4.0K ./3

24K

------------------------------------------------------------------------------------------------------------------

-c, --total produce a grand total

很简单：输入目录和子目录的总大小

[root@racnode1 aiki]# du --total

4 ./1

4 ./2/22

12 ./2

4 ./3

24 .

24 total

[root@racnode1 aiki]# du -c

4 ./1

4 ./2/22

12 ./2

4 ./3

24 .

24 total

6.小结

对于很多LINUX命令当不知道具体操作时要学会使用这些命令，而不当于是依靠GOOGLE,BAIDU......