Re: My script almost works but spams the terminal its launched from if useing dash.
On Saturday 16 April 2016 12:01:28 Aero Maxx wrote:
> On 16/04/2016 16:23, Gene Heskett wrote:
> > But when I run it with dash, it doesn't seem to work right, and
> > spams the terminal with its error messages. One that appears to
> > kill its function is the bashism of using [[ ]] to surround string
> > variables, reported like this:
> > bin/mailwatcher: 64: bin/mailwatcher: [[: not found
> > bin/mailwatcher: 70: bin/mailwatcher: [[: not found
> > bin/mailwatcher: 77: bin/mailwatcher: [[: not found
>
> dash isn't the same as bash, as it has a limited set of instructions
> or commands it can do.
>
> But I too would be interested to know if it is possible to get it to
> work in dash, I don't believe it is, but I am happy to be corrected
> or proved wrong.
>
> > And finally, once its working with either shell, how do I shut it up
> > totally? Even the above command line launch fails as it outputs to
> > that shell, a newline for every incoming mail which gradually
> > scrolls any output that was on-screen, offscreen without leaving a
> > prompt until I tap the return key to restore it.
>
> Also isn't the command you are running supposed to be as follows ?
>
> > bin/mailwatcher 2>&1 > /dev/null &
>
Is the space you inserted into my line between the > and the /dev/null a
game changer? In either bash or dash? Its been a while since I last
read the bash docs, but I don't recall there was any emphasis on that.
Looking at man bash, I see this:
The general format for redirecting output is:
[n]>word
Dash lists the same syntax as one of several variations.
So if either has changed to require a space there, it apparently hasn't
made it into the manpage. I dare say that such a change, breaking a
good share of our scripts, might lead to a search party carrying buckets
of verbal hot tar and big bags of verbal abuse feathers. ;-)
Me, goes off scratching whats left of a thinning head of hair.
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
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