ls

ls可以用来查看目录下文件与子目录信息

$ ls -lh
total 6.9G
-rw-rw-r-- 1 root root 531M Jul 12  2017 test1.txt
-rw-rw-r-- 1 root root 438M Jul 12  2017 test2.txt

查看指定文件信息

$ ls -lh test1.txt test2.txt
-rw-rw-r-- 1 root root 531M Jul 12  2017 test1.txt
-rw-rw-r-- 1 root root 438M Jul 12  2017 test2.txt

du

du是专门显示文件或目录大小信息的命令

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

  -0, --null            end each output line with 0 byte rather than newline
  -a, --all    #每个文件
      --apparent-size   #文件大小
  -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     
  -c, --total   #总的大小
  -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  #自动使用K,M,G
  -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   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 STYLE:
                          full-iso, long-iso, iso, +FORMAT
                          FORMAT is interpreted like '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

$du -h #显示当前文件和目录大小
812K    a.txt
444K    ./count

$ du -h *
531M    test1.sam
438M    test2.sam

$ du -h test1.sam
531M    test1.sam