On Tue, Apr 15, 2008 at 5:51 PM, Patrick O'Callaghan <pocallaghan@xxxxxxxxx> wrote:
Yes, and some of the most Unix/Linux knowledgeable people I know. :-)
I'm amazed it even exists on AIX. I was assuming you meant Linux (this
On Tue, 2008-04-15 at 16:56 -0700, Don Russell wrote:
>
>
> On Tue, Apr 15, 2008 at 4:17 PM, Cameron Simpson <cs@xxxxxxxxxx>
> wrote:
>
> On 15Apr2008 12:09, Don Russell <fedora@xxxxxxxxxxxxxxxxxxxxx>
> wrote:
> | On Tue, Apr 15, 2008 at 11:08 AM, Patrick O'Callaghan
> <pocallaghan@xxxxxxxxx>
> | wrote:
> | > On Tue, 2008-04-15 at 10:49 -0700, Don Russell wrote:
> | > > How can I tell, from a Korn shell script, if the script
> is running in
> | > > a vi sub-shell?
> | > >
> | > > I have a script that has a problem when run from a vi
> subshell, and
> | > > I'd like to check for that condition and just issue an
> error message.
> | > > (I know that's not the solution to the problem, but the
> thing that
> | > > fails is being replaced, so this is a temporary "fix")
> | >
> | > Try:
> | > ls -l /proc/`cat /proc/$$/status|grep PPid|cut -f2`/exe
> | > and work from there.
> |
> | That looks promising... thanks :-)
>
>
> Promising, but will work only on Linux. That may be enough for
> you, but you
> shouldn't forget that it's nonportable.
>
> I just tried this on a Linux system... it makes sense... I tried it on
> a UNIX (AIX) system, and it did not help directly. On UNIX the status
> file appears to be "raw" binary data that maps to a C structure...
> could get tricky trying to extract the correct parts.
is a Fedora list after all).
Yes, and some of the most Unix/Linux knowledgeable people I know. :-)
You can. Just put the wrapper in $HOME/bin and set PATH=$HOME/bin:$PATH, e.g.
> On Linux, it looks like that decoding is all done and present in
> human-readable terms. :-)
>
>
>
>
> You can probably make that `cat|grep|cut` into a single `sed`
> at some
> performance benefit.
>
> Another approach is to alter your shell environment to always
> set and export
> an environment variable when starting vi (by invoking vi via a
> wrapper script
> or alias or shell function) and then just checking for it.
>
> Though simple, that's not an option for me.... I can't "wrap" vi...
$ cat $HOME/vi
#!/bin/sh
export MY-SPECIAL-FLAG=1
exec /usr/bin/vi $*
$
Well, yes, I can do it for me, but I'm not in a position to do it for all the other users of the system to which I do not have root access. I *do* have control over the script they all use, which is why I want to detect "in a sub-shell" from that script, then I can just exit with an error message...
You've given me some good information... I just might have to decode the raw binary data on AIX instead of having the friendly text as seen on Linux. :-)
In the mean time, if people complain that it fails when run from a sub-shell, I just reply with "don't run it from a sub-shell". :-)
And maybe before too long, the whole point will be moot because the part that breaks right now will be replaced...
Still, a fun exercise. :-)
Cheers
