Both /sbin/sh and /usr/bin/sh shells are Bourne shells.
The difference is that /sbin/sh is statically linked and /usr/bin/sh is
dynamically linked. There is also /bin/sh, however /bin is just a symbolic
link to /usr/bin.
# ls -l /sbin/sh
-r-xr-xr-x 2 bin root 251712 Jul 16 1997 /sbin/sh
# file /sbin/sh
/sbin/sh: ELF 32-bit MSB executable SPARC Version 1, statically linked, stripped
# ldd /sbin/sh
ldd: /sbin/sh: file is not a dynamic executable or shared object
# ls -l /usr/bin/sh
-r-xr-xr-x 3 bin root 88620 Jul 16 1997 /usr/bin/sh
# file /usr/bin/sh
/usr/bin/sh: ELF 32-bit MSB executable SPARC Version 1, dynamically linked, stripped
# ldd /usr/bin/sh
libc.so.1 => /usr/lib/libc.so.1
libdl.so.1 => /usr/lib/libdl.so.1
Dynamically linked binaries use shared libraries during their execution. This
makes them smaller in size and when libraries get updated, the binaries will
automatically use the updated libraries.
Statically linked binaries contain all the code within them. They do not
use shared libraries at all. This makes them larger in size. The useful thing
about statically linked binaries is that they can run all by themselves as
they do not depend on shared libraries. If the system is "broken" and libraries
were removed, damaged, or /usr is not mounted, /sbin/sh can still be executed.
This is why it is recommended to use /sbin/sh as the default root shell.
| zhangbin 回复于：2002-09-20 08:52:01 |
| 长见识. |
| czc9 回复于：2002-09-20 08:58:27 |
| 好，应该加入精华区 |
| skip 回复于：2002-09-20 09:17:38 |
| 不错，up |
| zjfzq 回复于：2002-09-20 09:27:48 |
| 继续发扬 |
| 中原一片红 回复于：2002-09-20 09:36:02 |
| 好ENGLISH~~ |
| 风中男人 回复于：2002-09-20 10:01:48 |
| 是这样的，我的机器因为换了主板，而不能启动到单用户状态下，原来是/bin/sh ,后来我改成/sbin/sh 就能进入了。不错 |
| bear 回复于：2002-09-20 10:53:49 |
| 确实不错，进精 |
| 阿骁 回复于：2002-09-20 10:58:03 |
| 很好的对比，但这个概念论坛很早就有了，只是没有对比的那么详细！ |
| kinux 回复于：2002-09-20 11:53:43 |
谢谢你的分享!!! ^_^   |
| cfananbb 回复于：2002-10-13 10:11:54 |
| well done! |
| starwang 回复于：2002-10-13 23:44:26 |
| so good |
| kiner007 回复于：2002-10-14 09:20:50 |
| 好像以前看见过类似的文章 |
| wangqi 回复于：2002-10-29 15:50:06 |
| 不错，你也让大家明白了，希望多发表你的高见！ |
