fix(terraform_docs): Fix non-GNU sed issues, introduced in v1.93.0, as previous fix doesn't work correctly (antonbabenko#708)

Author: MaxymVlasov

README.md

@@ -585,8 +585,9 @@ Unlike most other hooks, this hook triggers once if there are any changed files
       To migrate everything to `terraform-docs` insertion markers, run in repo root:
 
       ```bash
-      grep -rl --null 'BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK' . | xargs -0 sed -i'' -e 's/BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK/BEGIN_TF_DOCS/'
-      grep -rl --null 'END OF PRE-COMMIT-TERRAFORM DOCS HOOK' . | xargs -0 sed -i'' -e 's/END OF PRE-COMMIT-TERRAFORM DOCS HOOK/END_TF_DOCS/'
+      sed --version &> /dev/null && SED_CMD=(sed -i) || SED_CMD=(sed -i '')
+      grep -rl --null 'BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK' . | xargs -0 "${SED_CMD[@]}" -e 's/BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK/BEGIN_TF_DOCS/'
+      grep -rl --null 'END OF PRE-COMMIT-TERRAFORM DOCS HOOK' . | xargs -0 "${SED_CMD[@]}" -e 's/END OF PRE-COMMIT-TERRAFORM DOCS HOOK/END_TF_DOCS/'
       ```
 
     ```yaml

hooks/terraform_docs.sh

@@ -40,8 +40,10 @@ function main {
 function replace_old_markers {
   local -r file=$1
 
-  sed -i'' -e "s/^${old_insertion_marker_begin}$/${insertion_marker_begin}/" "$file"
-  sed -i'' -e "s/^${old_insertion_marker_end}$/${insertion_marker_end}/" "$file"
+  # Determine the appropriate sed command based on the operating system (GNU sed or BSD sed)
+  sed --version &> /dev/null && SED_CMD=(sed -i) || SED_CMD=(sed -i '')
+  "${SED_CMD[@]}" -e "s/^${old_insertion_marker_begin}$/${insertion_marker_begin}/" "$file"
+  "${SED_CMD[@]}" -e "s/^${old_insertion_marker_end}$/${insertion_marker_end}/" "$file"
 }
 
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