我必须为我的大学完成一些活动，我需要知道命令是什么du -sm。我已经搜索了很多网站，但没有找到答案。
你能帮助我吗？
答案1
man您可以使用以下方式阅读此类内容
man du
那里说
du—估计文件空间使用情况
-m
类似 --block-size=1M
-B, --block-size=大小
在打印之前按 SIZE 缩放尺寸；例如，'-BM' 以 1,048,576 字节为单位打印尺寸；请参阅下面的 SIZE 格式
-s, --summarize 仅显示每个参数的总数
单数-通常表示单个字符参数，也--可以是整个单词。因此，当单数后面有多个字符时，-通常是组合。
答案2
我发现这在维基百科上，或者你可以使用
du --help
获取有关该命令的信息。
帮助命令内容：
Usage: du [OPTION]... [FILE]...
or: du [OPTION]... --files0-from=F
Summarize disk usage of the set of FILEs, recursively for directories.
Mandatory arguments to long options are mandatory for short options too.
-0, --null end each output line with NUL, not newline
-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 scale sizes by SIZE before printing them; e.g.,
'-BM' prints sizes in units of 1,048,576 bytes;
see SIZE format below
-b, --bytes equivalent to '--apparent-size --block-size=1'
-c, --total produce a grand total
-D, --dereference-args dereference only symlinks that are listed on the
command line
-d, --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
--files0-from=F summarize disk usage of the
NUL-terminated file names specified in file F;
if F is -, then read names from standard input
-H equivalent to --dereference-args (-D)
-h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G)
--inodes list inode usage information instead of block usage
-k like --block-size=1K
-L, --dereference dereference all symbolic links
-l, --count-links count sizes many times if hard linked
-m like --block-size=1M
-P, --no-dereference don't follow any symbolic links (this is the default)
-S, --separate-dirs for directories do not include size of subdirectories
--si like -h, but use powers of 1000 not 1024
-s, --summarize display only a total for each argument
-t, --threshold=SIZE exclude entries smaller than SIZE if positive,
or entries greater than SIZE if negative
--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, which can be:
full-iso, long-iso, iso, or +FORMAT;
FORMAT is interpreted like in 'date'
-X, --exclude-from=FILE exclude files that match any pattern in FILE
--exclude=PATTERN exclude files that match PATTERN
-x, --one-file-system skip directories on different file systems
--help display this help and exit
--version output version information and exit
Display values are in units of the first available SIZE from --block-size,
and the DU_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.
Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).
The SIZE argument is an integer and optional unit (example: 10K is 10*1024).
Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (powers of 1000).
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Full documentation at: <http://www.gnu.org/software/coreutils/du>
or available locally via: info '(coreutils) du invocation'