The gnu version of iconv offers a couple of internal filters for dealing with unsupported characters. They can be called in the shell program by tacking a string onto the "to" code. They may be undocumented in the man pages of some distros (or even unavailable?).
/usr/bin/iconv -f utf8 -t iso8895_15//IGNORE
/usr/bin/iconv -f utf8 -t iso8895_15//TRANSLIT
The first is equivalent to the -c
option. It will simply remove the unsupported character from the text. The second is smarter, and will attempt to substitute it with a similar character from the target set.