In /usr/bin/fftw-wisdom-to-conf line 39:
read preamble fftw_wisdom
^--^ SC2162: read without -r will mangle backslashes.


In /usr/bin/fftw-wisdom-to-conf line 43:
		prefix=`echo $fftw_wisdom | cut -d_ -f1`_
                       ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.
                             ^----------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
		prefix=$(echo "$fftw_wisdom" | cut -d_ -f1)_


In /usr/bin/fftw-wisdom-to-conf line 66:
sed 's/ *(//' | cut -d" " -f1 | grep -v -- - | egrep -v '^ *\)*$' | sort | uniq | while read reg_nam; do
                                               ^---^ SC2196: egrep is non-standard and deprecated. Use grep -E instead.
                                                                                        ^--^ SC2162: read without -r will mangle backslashes.

For more information:
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2162 -- read without -r will mangle backs...
  https://www.shellcheck.net/wiki/SC2196 -- egrep is non-standard and depreca...