In /usr/bin/compile_et line 23:
  if (set +x; test -z "`(eval $as_var=C; export $as_var) 2>&1`"); then
                       ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.
                                                ^-----^ SC2163: This does not export 'as_var'. Remove $/${} for that, or use ${var?} to quiet.

Did you mean: 
  if (set +x; test -z "$((eval $as_var=C; export $as_var) 2>&1)"); then


In /usr/bin/compile_et line 24:
    eval $as_var=C; export $as_var
                           ^-----^ SC2163: This does not export 'as_var'. Remove $/${} for that, or use ${var?} to quiet.


In /usr/bin/compile_et line 26:
    $as_unset $as_var
    ^-------^ SC2154: as_unset is referenced but not assigned.


In /usr/bin/compile_et line 39:
ROOT=`echo $1 | sed -e s/.et$//`
     ^-------------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
           ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
ROOT=$(echo "$1" | sed -e s/.et$//)


In /usr/bin/compile_et line 40:
BASE=`basename $ROOT`
     ^--------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
               ^---^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
BASE=$(basename "$ROOT")


In /usr/bin/compile_et line 48:
if test -f ${BASE}.h && cmp -s ${BASE}.h.$$ ${BASE}.h ; then
           ^-----^ SC2086: Double quote to prevent globbing and word splitting.
                               ^-----^ SC2086: Double quote to prevent globbing and word splitting.
                                            ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
if test -f "${BASE}".h && cmp -s "${BASE}".h.$$ "${BASE}".h ; then


In /usr/bin/compile_et line 49:
    rm -f ${BASE}.h.$$
          ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    rm -f "${BASE}".h.$$


In /usr/bin/compile_et line 51:
    mv -f ${BASE}.h.$$ ${BASE}.h
          ^-----^ SC2086: Double quote to prevent globbing and word splitting.
                       ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    mv -f "${BASE}".h.$$ "${BASE}".h


In /usr/bin/compile_et line 52:
    chmod a-w ${BASE}.h
              ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    chmod a-w "${BASE}".h


In /usr/bin/compile_et line 55:
if test -f ${BASE}.c && cmp -s ${BASE}.c.$$ ${BASE}.c ; then
           ^-----^ SC2086: Double quote to prevent globbing and word splitting.
                               ^-----^ SC2086: Double quote to prevent globbing and word splitting.
                                            ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
if test -f "${BASE}".c && cmp -s "${BASE}".c.$$ "${BASE}".c ; then


In /usr/bin/compile_et line 56:
    rm -f ${BASE}.c.$$
          ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    rm -f "${BASE}".c.$$


In /usr/bin/compile_et line 58:
    mv -f ${BASE}.c.$$ ${BASE}.c
          ^-----^ SC2086: Double quote to prevent globbing and word splitting.
                       ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    mv -f "${BASE}".c.$$ "${BASE}".c


In /usr/bin/compile_et line 59:
    chmod a-w ${BASE}.c
              ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    chmod a-w "${BASE}".c

For more information:
  https://www.shellcheck.net/wiki/SC2154 -- as_unset is referenced but not as...
  https://www.shellcheck.net/wiki/SC2163 -- This does not export 'as_var'. Re...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...