Re: [TUHS] Shell control through external commands - TUHS

10 Sep 2016

On 10 September 2016 at 05:41, Joerg Schilling &lt;schily(a)schily.net&gt; wrote:
...
  Michael Kjörling &lt;michael(a)kjorling.se&gt; 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. 
 It does appear rather useless. Curiously, Debian (checked on Wheezy =
 bash 4.2+dfsg-0.1+deb7u3 and Jessie = bash 4.3-11+b1) seems to not
 supply anything like that, so it would appear to be some kind of
 Fedora-ism rather than a part of anything upstream; that, or the
 Debian folks are actually paying attention to what they ship onto
 users' systems. 
 POSIX requires some commands to be callable via exec(). 
Solaris 10 has the following amusing implementation (/usr/bin/cd):

#!/bin/ksh -p
#
#ident  &quot;(a)(#)alias.sh   1.2     00/02/15 SMI"
#
# Copyright (c) 1995 by Sun Microsystems, Inc.
#
cmd=`basename $0`
$cmd "$@"

N.