Re: manual: a wrong description in sample scripts

[Paolo Bonzini]

On 05/26/2011 08:29 PM, Micah Cowan wrote:
> (05/25/2011 10:31 PM), wu liang wrote:
> > Sir,
> > In the chapter "4.2 Increment a Number", it is said " The tn commands
> > are not necessary, but make the thing
> >   faster". However it is not correct in case that  all the digits is 9.
> >   For example, 999 will not get result of 1000 but 2000, if there is no
> > tn command,since it will be addressed again in the following s
> > command.
>
> Yup.
>
> It also strikes me that the comment
>
> # replace all leading 9s by _ (any other character except digits, could
> # be used)
> :d
> s/9\(_*\)$/_\1/
> td
>
> is incorrect, since "leading" should mean the left-most digits, whereas
> this code is clearly replacing the right-most (trailing) digits.

I fixed both issues, thanks.

Regarding Wu's reported problem, in fact all but the first "tn" are 
unnecessary, and you can change the replacement from 1 to 0 in the first 
to eliminate the first "tn" as well.  This may be useful with sed 
implementations that have a hard limit on the number of commands.

Paolo