Baslinux mailing list

[3aoo-cvfd AT dea.spamcon.org]

Sheldon Isaac wrote:
>
> > if [ `pidof rpciod` > 0  ]
> > then
> >  echo FIC mounted
> >  PS1="FICon \w> "
> > else
> >  echo FIC not mounted
> >  PS1="\w> "
> > fi
>
> I'm not understanding how to do tests such as   Is this thing 
> equal/bigger/smaller, or  Is this thing null (whatever that is)  
> or  Does so-and-so exist
> 
> You saw the way I did it with the  bash  in BL2.1, apparently 
> was that a string or numeric comparison of `pidof rpciod`.

`pidof xxxx` simply outputs the process number of xxxx.
For example, try the following:
-----------
pidof kpiod
-----------
You will probably get 4 (kpiod is a kernel process that usually
runs in that position).

Now try this little script:
------------------------
if [ `pidof kpiod` > 0 ]
  then echo yes
  else echo no
fi
------------------------
It should output yes.  If you edit the script and change kpiod
to xxx (or other nonsense), it should output no.

> But I can' t find simple lessons on how to say it so that  
> sh will do it.

sh does it just fine.  I've just run the above script in BL3.

> I need to know how to do   if then else  and   case  and such stuff.

As you can see "if then else" works fine in BL3.  So does "case":
-----------------------------------
case `pidof kpiod` in 4) echo yes;;
                      *) echo no
esac
-----------------------------------
I've just run that script in BL3 too.  

> Are there functions like length, 

Yes.
------------------
a=apple; length $a
------------------

> as in 
> if length(`pidof rpciod`) -gt 0;

This works on BL3:
------------------------
a=apple
if [ `length $a` -gt 0 ]
  then echo yes
  else echo no
fi
------------------------
However, if $a is null, length treats it like --help and you get
some usage junk.

> or is it length(string(`pidof rpciod`))   

length does not use (
There is no string command.

Cheers,
Steven