Re: Bash string substitution bug (?)

[Bernd Eggink]

Dmitry V Golovashkin schrieb:

> Description:
>    unexpected bad substitution:
>    enter the following simple list:
>
>     prompt:  CLUSTER='1 2'; echo ${CLUSTER/${HOSTNAME%%.*}}
>     output:       1 2
>
>    the idea of the above line is to remove short HOSTNAME (without the 
> trailing domain)
>          from the CLUSTER - works fine (CLUSTER was assigned a dummy 
> value - irrelevant)
>    however the same operation with slash results in a bad substitution 
> error.
>    the substitution appears to be a valid one.
>
>       prompt: CLUSTER='1 2'; echo ${CLUSTER/${HOSTNAME/.*}}
>       output:             -bash: ${HOSTNAME: bad substitution

Apparently bash interprets this as  ${parameter/pattern/string}
where pattern = ${HOSTNAME. Looks like a bug; it works in ksh.

As a workaround, you could use:

        H=${HOSTNAME/.*}
        echo ${CLUSTER/$H}

Regards,
Bernd

--
Bernd Eggink
monoped@sudrala.de
http://sudrala.de