More efficient use of jq.

Author: bluegate010

.github/workflows/render.yml

@@ -86,15 +86,13 @@ jobs:
             if echo "${input}" | jq -e '.append_git_rev_to_version' > /dev/null; then
               echo "Appending git rev to version string in ${src}"
 
-              # The sed command handles the following transformations:
               # `version: 1.3` --> `version: 1.3 (Git commit xyz)`
               # `version: "2.0"` --> `version: "2.0 (Git commit xyz)"`
               sed -i -r "/^---$/,/^---$/s/^(version: \"?[^\"]*)(\"?)$/\1 (Git commit ${commit_hash})\2/g" "${src}"
             fi
 
-            if echo "${input}" | jq -e 'has("gh_pages_html")' > /dev/null; then
-              gh_pages_html=$(echo "${input}" | jq -r '.gh_pages_html')
-
+            gh_pages_html=$(echo "${input}" | jq -e -r '.gh_pages_html')
+            if [ $? -eq 0 ]; then
               echo "Rendering ${src} to gh-pages/${gh_pages_html}/index.html"
 
               (cd "${src_dirname}" && exec \
@@ -113,9 +111,8 @@ jobs:
               mv "${src_dirname}/index.html" "gh-pages/${gh_pages_html}/"
             fi
 
-            if echo "${input}" | jq -e 'has("gh_pages_pdf")' > /dev/null; then
-              gh_pages_pdf=$(echo "${input}" | jq -r '.gh_pages_pdf')
-
+            gh_pages_pdf=$(echo "${input}" | jq -e -r '.gh_pages_pdf')
+            if [ $? -eq 0 ]; then
               # [parent dir name]_[filename sans extension]_[git commit hash].pdf
               pdf_name="$(basename "${src_dirname}")_${src_basename%.*}_${commit_hash}.pdf"