Hi,
This is a bug. What happens at line #236 in PreProcessorContext.java is
basically as follows:
$FILTER".replaceFirst("\\$FILTER", "($0 == 'a')"));
This returns ($FILTER == 'a').
The reason is explained in the Java doc for String class:
Note that backslashes (\) and dollar signs ($) in the replacement string
> may cause the results to be different than if it were being treated as a
> literal replacement string. Dollar signs may be treated as references to
> captured subsequences as described above, and backslashes are used to
> escape literal characters in the replacement string.
I guess that the fix is to escape the $ and \ chars in the replacement
string before calling replaceFirst(). I will open a jira for this.
Thanks,
Cheolsoo
On Mon, Sep 24, 2012 at 7:51 PM, Huo Zhu <[email protected]> wrote:
> hi, i recently find this problem when i using parameter substitution in
> pig script
>
> my test.pig
>
> a = load ‘data' as (ch:chararray, num:int)
> > b = filter by $FILTER
>
>
>
> i execute this script with, ( i need to use positional notation to refer ch
> )
>
> pig -x local -dryrun -p FILTER=“ (\$0 == 'a') " -f test.pig
>
>
> the test.pig.substituted is
>
> b = filter by ($FILTER == 'a')
>
>
> why is \$0 replaced by $FILTER even i escaped the '$'
>
> --
> Good Luck
>
