Append White Space using preprocessor

System

When extracting metadata from a html file, I need to replace any new line character with a white space. In the .ism file, I put:

action PUT_SPACE
{
appendb(" ");
}
...
state START_MYTAG
NEWLINE PUT_SPACE START_MYTAG

...

When I see the dump of bufferB, the new line characters are gone, but no white space added to replace them. If I change the PUT_SPACE to appendb("\s"), the dump of bufferB shows "\s" in the places where the new lines are originally there.

I guess MetaTagger does not like it when I specify white space as " ". What can I use instead to fix this?

Thanks in advance!