regexp bug in sed/grep?

[Miles Bader]

In the following command, I think the `ABx' suffix should be deleted by
the sed program, but it isn't:

   $ echo pqrABx | sed -e 's/AB*x?$//'
   pqrABx

grep fails similarly:

   $ echo pqrABx | grep 'AB*x?$'
   <no output>

If I try the equivalent AWK program, it works as I expect:

   $ echo pqrABx | nawk '{ sub (/AB*x?$/, ""); print }'
   pqr

Is this a bug with the regexp implementation in sed/grep, or am I just
confused?

Thanks,

-Miles

-- 
Somebody has to do something, and it's just incredibly pathetic that it
has to be us.  -- Jerry Garcia
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