In /usr/bin/m17n-db line 65:
ENTRIES=`sed -n "/$TAG0/s|$SPC($TAGS$FILE).*$|/\1/\2/\3/\4/\5|p" $DIRFILE`
        ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
ENTRIES=$(sed -n "/$TAG0/s|$SPC($TAGS$FILE).*$|/\1/\2/\3/\4/\5|p" $DIRFILE)


In /usr/bin/m17n-db line 67:
cd $datadir/m17n
^--------------^ SC2164: Use 'cd ... || exit' or 'cd ... || return' in case cd fails.

Did you mean: 
cd $datadir/m17n || exit


In /usr/bin/m17n-db line 70:
    FN=`expr "$e" : "/[^/]*/[^/]*/[^/]*/[^/]*/\(.*\)"`
       ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
    FN=$(expr "$e" : "/[^/]*/[^/]*/[^/]*/[^/]*/\(.*\)")


In /usr/bin/m17n-db line 74:
		if test -f $f; then
                           ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
		if test -f "$f"; then


In /usr/bin/m17n-db line 75:
		    ENTRY=`sed -n "/$TAG0/s|$SPC($TAGS).*$|/\1/\2/\3/\4|p" $f`
                          ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.
                                                                           ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
		    ENTRY=$(sed -n "/$TAG0/s|$SPC($TAGS).*$|/\1/\2/\3/\4|p" "$f")


In /usr/bin/m17n-db line 82:
	    if test -f $FN; then
                       ^-^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
	    if test -f "$FN"; then


In /usr/bin/m17n-db line 90:
	/$TAG0/$TAG1/$TAG2/$TAG3)
        ^----------------------^ SC2254: Quote expansions in case patterns to match literally rather than as a glob.


In /usr/bin/m17n-db line 91:
	    FN=`expr "$l" : "/[^/]*/[^/]*/[^/]*/[^/]*/\(.*\)"`
               ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
	    FN=$(expr "$l" : "/[^/]*/[^/]*/[^/]*/[^/]*/\(.*\)")


In /usr/bin/m17n-db line 92:
	    echo "`pwd`/$FN"
                  ^---^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
	    echo "$(pwd)/$FN"

For more information:
  https://www.shellcheck.net/wiki/SC2164 -- Use 'cd ... || exit' or 'cd ... |...
  https://www.shellcheck.net/wiki/SC2254 -- Quote expansions in case patterns...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...