In /usr/bin/db2html line 4:
for arg in $*
           ^-- SC2048: Use "$@" (with quotes) to prevent whitespace problems.


In /usr/bin/db2html line 8:
    skip=$(($skip - 1))
            ^---^ SC2004: $/${} is unnecessary on arithmetic variables.


In /usr/bin/db2html line 17:
  *)	output="$(echo $arg | sed 's,\.sgml$,,;s,\.sgm$,,;s,\.xml$,,')"
                       ^--^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
  *)	output="$(echo "$arg" | sed 's,\.sgml$,,;s,\.sgm$,,;s,\.xml$,,')"


In /usr/bin/db2html line 23:
if [ -d ${output} ]
        ^-------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
if [ -d "${output}" ]


In /usr/bin/db2html line 25:
  rm -rf ${output}.junk
         ^-------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
  rm -rf "${output}".junk


In /usr/bin/db2html line 26:
  mv ${output} ${output}.junk
     ^-------^ SC2086: Double quote to prevent globbing and word splitting.
               ^-------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
  mv "${output}" "${output}".junk


In /usr/bin/db2html line 28:
mkdir ${output}
      ^-------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
mkdir "${output}"


In /usr/bin/db2html line 29:
jw -f docbook -b html -o ${output} "$@"
                         ^-------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
jw -f docbook -b html -o "${output}" "$@"

For more information:
  https://www.shellcheck.net/wiki/SC2048 -- Use "$@" (with quotes) to prevent...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2004 -- $/${} is unnecessary on arithmeti...