Hi, I'm confused about sh. someone help me.Thanks!
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depand on. There are several sh in the system.
For example, in Solaris,
-bash-3.00$ ls -l /usr/bin/sh
lrwxrwxrwx 1 root root 13 Mar 5 2007 /usr/bin/sh -> ../../sbin/sh
-bash-3.00$ ls -l /bin/sh
lrwxrwxrwx 1 root root 13 Mar 5 2007 /bin/sh -> ../../sbin/sh
So both /usr/bin/sh and /bin/sh are link, link to /sbin/sh (real sh)
en,thaks.
And the 2nd question:
if we say sh, does that mean the earliest shell on Unix, I mean the real file?
at rhel 5.5 here:
[root@newinstaller19 ~]# which sh
/bin/sh
[root@newinstaller19 ~]# ls -l /bin/sh
lrwxrwxrwx 1 root root 4 Oct 12 09:28 /bin/sh -> bash
[root@newinstaller19 ~]#
and then:
[root@newinstaller19 ~]# which bash
/bin/bash
[root@newinstaller19 ~]# ls -l /bin/bash
-rwxr-xr-x 1 root root 801512 Oct 21 2008 /bin/bash
[root@newinstaller19 ~]#
---------- Post updated at 04:56 PM ---------- Previous update was at 04:52 PM ----------
why don't you read Unix shell - Wikipedia, the free encyclopedia
AFAIK of the modern OS, only on Solaris /bin/sh points to an actual bare-bones Bourne Shell, which is indeed the "earliest shell".
On most other modern systems /bin/sh is either a soft link or a hard link to a POSIX-compliant shell, which may have additional features.
On Solaris, /usr/xpg4/bin/sh should be used instead.
If you stick to the features listed on this page: POSIX Shell & Utilities your scripts should work across platforms...
thanks a lot to all of you guys.
And HP-UX /sbin/sh... the /usr/bin/sh is the posix...
ran:/sbin $ file sh
sh: PA-RISC1.1 shared executable
ran:/sbin $ file /usr/bin/sh
/usr/bin/sh: PA-RISC1.1 shared executable dynamically linked
ran:/sbin $
Why in /sbin? It belongs to root FS, not the case of the others (/usr on separate FS...)
It helps when in single user doing maintenance...
And because /sbin/sh is statically linked and does not need additional libraries, so that it will run even if the libraries become unavailable.
What does /bin/sh point to on HPUX?
In our HP-UX, /bin/sh -> /usr/bin/sh
So that is the Posix Shell that vbe mentioned. Thanks...
then, how to determine it's a posix shell or a bourne shell
Look it up in the man page:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c02267599/c02267599.pdf
clear! thanks again to all!!!