在Linux中显示文件列表/文件大小等文件信息的时候，通常的做法是使用“ls -l”或者ll，这里显示显示的大小是文件的字节大小。
但是，如果文件比较大的话，显示起来不是特别易读，需要单独的计算。这个时候，可以使用“ls -lh”，就可以使用比较接近文件大小的单位显示文件的大小，如下：：
使用“-h”参数时，会根据文件的大小选择显示的单位是“K”、“M”还是“G”。如果希望指定显示的单位，可以使用“--block-size”参数，如下：
对比可以看到，使用 不同的单位显示的时候，使用的是进一法，所以一个1k的东西，使用G为单位显示的是，会显示为“1G”。所以，还是使用“-h”显示起来，更符合人的习惯。
下面是ls显示的相关描述：
LS(1) User Commands LS(1)
NAME
ls - list directory contents
SYNOPSIS
ls [OPTION]... [FILE]...
DESCRIPTION
List information about the FILEs (the current directory by default). Sort entries alphabetically if none of -cftuvSUX nor --sort is specified.
Mandatory arguments to long options are mandatory for short options too.
-a, --all
do not ignore entries starting with .
-A, --almost-all
do not list implied . and ..
--author
with -l, print the author of each file
-b, --escape
print C-style escapes for nongraphic characters
--block-size=SIZE
scale sizes by SIZE before printing them. E.g., `--block-size=M' prints sizes in units of 1,048,576 bytes. See SIZE format below.
-B, --ignore-backups
do not list implied entries ending with ~
-c with -lt: sort by, and show, ctime (time of last modification of file status information) with -l: show ctime and sort by name otherwise: sort by ctime, newest first
-C list entries by columns
--color[=WHEN]
colorize the output. WHEN defaults to `always' or can be `never' or `auto'. More info below
-d, --directory
list directory entries instead of contents, and do not dereference symbolic links
-D, --dired
generate output designed for Emacs' dired mode
-f do not sort, enable -aU, disable -ls --color
-F, --classify
append indicator (one of */=>@|) to entries
--file-type
likewise, except do not append `*'
--format=WORD
across -x, commas -m, horizontal -x, long -l, single-column -1, verbose -l, vertical -C
--full-time
like -l --time-style=full-iso
-g like -l, but do not list owner
--group-directories-first
group directories before files.
augment with a --sort option, but any use of --sort=none (-U) disables grouping
-G, --no-group
in a long listing, don't print group names
-h, --human-readable
with -l, print sizes in human readable format (e.g., 1K 234M 2G)
--si likewise, but use powers of 1000 not 1024
-H, --dereference-command-line
follow symbolic links listed on the command line
--dereference-command-line-symlink-to-dir
follow each command line symbolic link that points to a directory
--hide=PATTERN
do not list implied entries matching shell PATTERN (overridden by -a or -A)
--indicator-style=WORD
append indicator with style WORD to entry names: none (default), slash (-p), file-type (--file-type), classify (-F)
-i, --inode
print the index number of each file
-I, --ignore=PATTERN
do not list implied entries matching shell PATTERN
-k like --block-size=1K
-l use a long listing format
-L, --dereference
when showing file information for a symbolic link, show information for the file the link references rather than for the link itself
-m fill width with a comma separated list of entries
-n, --numeric-uid-gid
like -l, but list numeric user and group IDs
-N, --literal
print raw entry names (don't treat e.g. control characters specially)
-o like -l, but do not list group information
-p, --indicator-style=slash
append / indicator to directories
-q, --hide-control-chars
print ? instead of non graphic characters
--show-control-chars
show non graphic characters as-is (default unless program is `ls' and output is a terminal)
-Q, --quote-name
enclose entry names in double quotes
--quoting-style=WORD
use quoting style WORD for entry names: literal, locale, shell, shell-always, c, escape
-r, --reverse
reverse order while sorting
-R, --recursive
list subdirectories recursively
-s, --size
print the allocated size of each file, in blocks
-S sort by file size
--sort=WORD
sort by WORD instead of name: none -U, extension -X, size -S, time -t, version -v
--time=WORD
with -l, show time as WORD instead of modification time: atime -u, access -u, use -u, ctime -c, or status -c; use specified time as sort key if --sort=time
--time-style=STYLE
with -l, show times using style STYLE: full-iso, long-iso, iso, locale, +FORMAT. FORMAT is interpreted like `date'; if FORMAT is FORMAT1<newline>FORMAT2, FORMAT1 applies to non-recent files
and FORMAT2 to recent files; if STYLE is prefixed with `posix-', STYLE takes effect only outside the POSIX locale
-t sort by modification time, newest first
-T, --tabsize=COLS
assume tab stops at each COLS instead of 8
-u with -lt: sort by, and show, access time with -l: show access time and sort by name otherwise: sort by access time
-U do not sort; list entries in directory order
-v natural sort of (version) numbers within text
-w, --width=COLS
assume screen width instead of current value
-x list entries by lines instead of by columns
-X sort alphabetically by entry extension
-Z, --context
print any SELinux security context of each file
-1 list one file per line
--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.
Using color to distinguish file types is disabled both by default and with --color=never. With --color=auto, ls emits color codes only when standard output is connected to a terminal. The LS_COL‐
ORS environment variable can change the settings. Use the dircolors command to set it.
Exit status:
0 if OK,
1 if minor problems (e.g., cannot access subdirectory),
2 if serious trouble (e.g., cannot access command-line argument).
AUTHOR
Written by Richard M. Stallman and David MacKenzie.
REPORTING BUGS
Report ls bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report ls translation bugs to <http://translationproject.org/team/>
COPYRIGHT
Copyright © 2011 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
The full documentation for ls is maintained as a Texinfo manual. If the info and ls programs are properly installed at your site, the command
info coreutils 'ls invocation'
should give you access to the complete manual.
GNU coreutils 8.12.197-032bb September 2011 LS(1)