INPUT=ABC; INPUT=${(S)INPUT//#%((#b)(*))/°match°}; print $match

#no output

# Try to quote #

INPUT=ABC; INPUT=${(S)INPUT//\#\%((#b)(*))/°match°}; print $match

#no output

# Anchor with (#s)/(#e) instead:

INPUT=ABC; INPUT=${(S)INPUT//(#s)((#b)(*))(#e)/°match°}; print $match

#ouput correct:

ABC

# No S-flag

INPUT=ABC; INPUT=${INPUT//#%((#b)(*))/°match°}; print $match

#output correct

ABC

BTW, what were the rules of (#b) flag activity (or (#B))? It was something about "till the end of the parens".

Best regards,

Sebastian Gniazdowski