10 Sep
2016
10 Sep
'16
11:06 p.m.
On Sat, Sep 10, 2016, at 05:13, Michael Kjörling wrote:
On 10 Sep 2016 09:45 +0200, from dnied(a)tiscali.it
(Dario Niedermann):
> Il 15/07/2016 alle 14:27, Norman Wilson ha scritto:
>> lu$ cat /bin/cd
>> #!/bin/sh
>> builtin cd "$@"
>> lu$
>
> But doesn't this change the current dir only in the child shell?
> Which then exits right after the second line, parent shell's $PWD
> unaffected. I really don't see how this script is useful.
I've wondered about this in the past, the conclusion was that it is
something that is technically required by POSIX. There is a general
requirement that "regular builtin" commands [with no exception for cd]
"shall be implemented in a manner so that they can be accessed via the
exec family of functions as defined in the System Interfaces volume of
POSIX.1-2008 and can be invoked directly by those standard utilities
that require it (env, find, nice, nohup, time, xargs)."