[ferret_users] string comparison

[Sudheer Joseph <sjo.india@xxxxxxxxx>]

Dear Users,
                             Is there any way in ferret to do string comparison,

ie, I want to use the unit information in netcdf variable and do
action based on that.
Also if there is no unit for the variable the code should not break
instead continue echoing that there was no unit.
it could  be some thing like below

use monthly_navy_winds

def sym unt=`uwnd,r=ubnit`
if (($unt) eq "cm") then
nwnd=uwnd/100
else
nwnd=uwnd
end if

though the above code is written it will break if a data file do not
have unit information