Alpine Linux 是一个基于 musl libc 和 busybox 的轻量级Linux发行版，busybox 实现了很多常用类Unix命令的精简版，特点是体积很小，舍弃了很多不常用参数，我们简单对比一下标准Linux自带的 ls命令 和Alpine下的 ls 命令便可略知一二：
root@spacex:~# ls --help
Usage: ls [OPTION]... [FILE]...
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 with -l, scale sizes by SIZE when printing them;
e.g., '--block-size=M'; 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 can be 'always' (default
if omitted), 'auto', or 'never'; more info below
-d, --directory list directories themselves, not their contents
-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;
can be augmented 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 and -s, print sizes like 1K 234M 2G etc.
--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)
--hyperlink[=WHEN] hyperlink file names; WHEN can be 'always'
(default if omitted), 'auto', or 'never'
--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, --kibibytes default to 1024-byte blocks for disk usage;
used only with -s and per directory totals
-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 entry names without quoting
-o like -l, but do not list group information
-p, --indicator-style=slash
append / indicator to directories
-q, --hide-control-chars print ? instead of nongraphic characters
--show-control-chars show nongraphic characters as-is (the 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,
shell-escape, shell-escape-always, c, escape
(overrides QUOTING_STYLE environment variable)
-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, largest first
--sort=WORD sort by WORD instead of name: none (-U), size (-S),
time (-t), version (-v), extension (-X)
--time=WORD change the default of using modification times;
access time (-u): atime, access, use;
change time (-c): ctime, status;
birth time: birth, creation;
with -l, WORD determines which time to show;
with --sort=time, sort by WORD (newest first)
--time-style=TIME_STYLE time/date format with -l; see TIME_STYLE below
-t sort by time, newest first; see --time
-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, newest first
-U do not sort; list entries in directory order
-v natural sort of (version) numbers within text
-w, --width=COLS set output width to COLS. 0 means no limit
-x list entries by lines instead of by columns
-X sort alphabetically by entry extension
-Z, --context print any security context of each file
-1 list one file per line. Avoid '\n' with -q or -b
--help display this help and exit
--version output version information and exit
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).
Binary prefixes can be used, too: KiB=K, MiB=M, and so on.
The TIME_STYLE argument can be full-iso, long-iso, iso, locale, or +FORMAT.
FORMAT is interpreted like in date(1). If FORMAT is FORMAT1<newline>FORMAT2,
then FORMAT1 applies to non-recent files and FORMAT2 to recent files.
TIME_STYLE prefixed with 'posix-' takes effect only outside the POSIX locale.
Also the TIME_STYLE environment variable sets the default style to use.
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_COLORS 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).
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Full documentation <https://www.gnu.org/software/coreutils/ls>
or available locally via: info '(coreutils) ls invocation'
可以看到参数少了很多，虽然大部分情况下busybox的命令都足够用了，但特殊情况下可能并不能满足我们的需求，比如要运行一个基于标准Linux编写的shell脚本，其中用了很多命令的高级参数，对此，Alpine Linux 也提供了替换标准Linux 命令的方法。
默认情况下，Alpine下的一些常用Linux 命令其实都是指向 busybox 的软链，包括 ls 命令本身
除了上述列出的 /bin 目录下命令，还有 /sbin/， /usr/bin/，/usr/sbin/ 目录下的大多命令都是如此。
要想替换Alpine 下的所有 busybox 命令，我们可以执行：
apk add util-linux pciutils hwdata-pci usbutils hwdata-usb coreutils binutils findutils grep iproute2 bash bash-completion
替换完之后，这些软链接要么被替换成了具体的可执行文件，要么还是软链，但不再指向busybox了：
如果只想替换某个具体用到的，那就要找出该命令所在的 GNU 工具包了，然后只安装该工具包即可，从而尽量保持体积不要太过膨胀，根据我目前的经验找出某个具体命令所在的工具包大致有以下几种方法供参考：
- 查看标准Linux命令的帮助文档
比如从 date --help 的帮助文档我们可以知道它在 GNU coreutils 工具包下：
- 查看busybox项目的源码结构和文件命名，busybox通常一个命令就是一个源码文件。
比如 fdisk,flock, getopt 这些命令都是由 util-linux 包提供的，如果我们只用到其中的命令，只安装 util-linux 即可
同理，find, grep, xargs 三个命令由 findutils 包提供
还可以直接尝试搜索某个命令，看是否有对应的源文件，直接就能定位到软件包：
- 用
apk info查看某个包的具体介绍，从而推断可能有哪些命令
- 实在不行只能一个个的尝试，看到安装了哪个包之后，目标软件的软链被替换掉了，说明这个就是我们要找的。
