fix: lint errors from scripts/checkstyle.py (#1385)

Co-authored-by: James Hegedus <jthegedus@hey.com>

.editorconfig

@@ -6,3 +6,6 @@ indent_size = 2
 charset = utf-8
 trim_trailing_whitespace = true
 insert_final_newline = true
+
+[*.py]
+indent_size = 4

.github/workflows/lint.yml

@@ -33,3 +33,15 @@ jobs:
 
       - name: Run shfmt
         run: scripts/shfmt.bash
+
+  checkstyle-py:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Install asdf dependencies
+        uses: asdf-vm/actions/install@v1
+
+      - name: Run checkstyle.py
+        run: scripts/checkstyle.py

.tool-versions

@@ -1,3 +1,4 @@
 bats 1.7.0
 shellcheck 0.8.0
 shfmt 3.5.1
+python 3.10.9

lib/commands/command-current.bash

@@ -44,7 +44,7 @@ plugin_current_command() {
 
 # shellcheck disable=SC2059
 current_command() {
-  local terminal_format="%-15s %-15s %-10s\\n"
+  local terminal_format="%-15s %-15s %-10s\n"
   local exit_status=0
   local plugin
 
@@ -75,8 +75,8 @@ check_for_deprecated_plugin() {
   local new_script="${plugin_path}/bin/list-legacy-filenames"
 
   if [ "$legacy_config" = "yes" ] && [ -f "$deprecated_script" ] && [ ! -f "$new_script" ]; then
-    printf "Heads up! It looks like your %s plugin is out of date. You can update it with:\\n\\n" "$plugin_name"
+    printf "Heads up! It looks like your %s plugin is out of date. You can update it with:\n\n" "$plugin_name"
-    printf "  asdf plugin-update %s\\n\\n" "$plugin_name"
+    printf "  asdf plugin-update %s\n\n" "$plugin_name"
   fi
 }
 

lib/commands/command-env.bash

@@ -6,7 +6,7 @@ shim_env_command() {
   local env_args=("${@:3}")
 
   if [ -z "$shim_name" ]; then
-    printf "usage: asdf env <command>\\n"
+    printf "usage: asdf env <command>\n"
     exit 1
   fi
 

lib/commands/command-exec.bash

@@ -6,7 +6,7 @@ shim_exec_command() {
   local shim_args=("${@:2}")
 
   if [ -z "$shim_name" ]; then
-    printf "usage: asdf exec <command>\\n"
+    printf "usage: asdf exec <command>\n"
     exit 1
   fi
 
@@ -16,7 +16,7 @@ shim_exec_command() {
     local executable_path="$3"
 
     if [ ! -x "$executable_path" ]; then
-      printf "No %s executable found for %s %s\\n" "$shim_name" "$plugin_name" "$version" >&2
+      printf "No %s executable found for %s %s\n" "$shim_name" "$plugin_name" "$version" >&2
       exit 2
     fi
 

lib/commands/command-export-shell-version.bash

@@ -8,8 +8,8 @@ shell_command() {
   shift
 
   if [ "$#" -lt "2" ]; then
-    printf "Usage: asdf shell <name> {<version>|--unset}\\n" >&2
+    printf "Usage: asdf shell <name> {<version>|--unset}\n" >&2
-    printf "false\\n"
+    printf "false\n"
     exit 1
   fi
 
@@ -23,7 +23,7 @@ shell_command() {
   if [ "$version" = "--unset" ]; then
     case "$asdf_shell" in
     fish)
-      printf "set -e %s\\n" "$version_env_var"
+      printf "set -e %s\n" "$version_env_var"
       ;;
     elvish)
       # Elvish doesn't have a `source` command, and eval is banned, so the
@@ -32,7 +32,7 @@ shell_command() {
       printf "unset-env\n%s" "$version_env_var"
       ;;
     *)
-      printf "unset %s\\n" "$version_env_var"
+      printf "unset %s\n" "$version_env_var"
       ;;
     esac
     exit 0
@@ -42,13 +42,13 @@ shell_command() {
   fi
   if ! (check_if_version_exists "$plugin" "$version"); then
     version_not_installed_text "$plugin" "$version" 1>&2
-    printf "false\\n"
+    printf "false\n"
     exit 1
   fi
 
   case "$asdf_shell" in
   fish)
-    printf "set -gx %s \"%s\"\\n" "$version_env_var" "$version"
+    printf "set -gx %s \"%s\"\n" "$version_env_var" "$version"
     ;;
   elvish)
     # Elvish doesn't have a `source` command, and eval is banned, so the
@@ -57,7 +57,7 @@ shell_command() {
     printf "set-env\n%s\n%s" "$version_env_var" "$version"
     ;;
   *)
-    printf "export %s=\"%s\"\\n" "$version_env_var" "$version"
+    printf "export %s=\"%s\"\n" "$version_env_var" "$version"
     ;;
   esac
 }

lib/commands/command-help.bash

@@ -3,7 +3,7 @@
 . "$(dirname "$(dirname "$0")")/lib/functions/versions.bash"
 
 asdf_help() {
-  printf "version: %s\\n\\n" "$(asdf_version)"
+  printf "version: %s\n\n" "$(asdf_version)"
   cat "$(asdf_dir)/help.txt"
 }
 
@@ -23,7 +23,7 @@ asdf_extension_cmds() {
     ext_cmd_path="$plugin_path/lib/commands"
     ext_cmds="$(find "$ext_cmd_path" -name "command*.bash" 2>/dev/null)"
     if [[ -n $ext_cmds ]]; then
-      printf "\\nPLUGIN %s\\n" "$plugin"
+      printf "\nPLUGIN %s\n" "$plugin"
       for ext_cmd in $ext_cmds; do
         ext_cmd_name="$(basename "$ext_cmd")"
         sed "s/-/ /g;s/.bash//;s/command-*/  asdf $plugin/;" <<<"$ext_cmd_name"
@@ -78,11 +78,11 @@ help_command() {
           (print_plugin_help "$plugin_path")
         fi
       else
-        printf "No documentation for plugin %s\\n" "$plugin_name" >&2
+        printf "No documentation for plugin %s\n" "$plugin_name" >&2
         exit 1
       fi
     else
-      printf "No plugin named %s\\n" "$plugin_name" >&2
+      printf "No plugin named %s\n" "$plugin_name" >&2
       exit 1
     fi
   else

lib/commands/command-info.bash

@@ -3,11 +3,11 @@
 . "$(dirname "$(dirname "$0")")/lib/functions/plugins.bash"
 
 info_command() {
-  printf "%s:\\n%s\\n\\n" "OS" "$(uname -a)"
+  printf "%s:\n%s\n\n" "OS" "$(uname -a)"
-  printf "%s:\\n%s\\n\\n" "SHELL" "$($SHELL --version)"
+  printf "%s:\n%s\n\n" "SHELL" "$($SHELL --version)"
-  printf "%s:\\n%s\\n\\n" "ASDF VERSION" "$(asdf_version)"
+  printf "%s:\n%s\n\n" "ASDF VERSION" "$(asdf_version)"
-  printf "%s:\\n%s\\n\\n" "ASDF ENVIRONMENT VARIABLES" "$(env | grep -E "ASDF_DIR|ASDF_DATA_DIR|ASDF_CONFIG_FILE|ASDF_DEFAULT_TOOL_VERSIONS_FILENAME")"
+  printf "%s:\n%s\n\n" "ASDF ENVIRONMENT VARIABLES" "$(env | grep -E "ASDF_DIR|ASDF_DATA_DIR|ASDF_CONFIG_FILE|ASDF_DEFAULT_TOOL_VERSIONS_FILENAME")"
-  printf "%s:\\n%s\\n\\n" "ASDF INSTALLED PLUGINS" "$(plugin_list_command --urls --refs)"
+  printf "%s:\n%s\n\n" "ASDF INSTALLED PLUGINS" "$(plugin_list_command --urls --refs)"
 }
 
 info_command "$@"

lib/commands/command-list.bash

@@ -11,11 +11,11 @@ list_command() {
     if find "$plugins_path" -mindepth 1 -type d &>/dev/null; then
       for plugin_path in "$plugins_path"/*/; do
         plugin_name=$(basename "$plugin_path")
-        printf "%s\\n" "$plugin_name"
+        printf "%s\n" "$plugin_name"
         display_installed_versions "$plugin_name" "$query"
       done
     else
-      printf "%s\\n" 'No plugins installed'
+      printf "%s\n" 'No plugins installed'
     fi
   else
     check_if_plugin_exists "$plugin_name"
@@ -49,7 +49,7 @@ display_installed_versions() {
       if [[ "$version" == "$current_version" ]]; then
         flag=" *"
       fi
-      printf "%s%s\\n" "$flag" "$version"
+      printf "%s%s\n" "$flag" "$version"
     done
   else
     display_error '  No versions installed'

lib/commands/command-plugin-list-all.bash

@@ -18,11 +18,11 @@ plugin_list_all_command() {
 
         [[ -d "${plugins_local_path}/${index_plugin_name}" ]] && installed_flag='*'
 
-        printf "%s\\t%s\\n" "$index_plugin_name" "$installed_flag$source_url"
+        printf "%s\t%s\n" "$index_plugin_name" "$installed_flag$source_url"
       done
     ) | awk '{ printf("%-28s", $1); sub(/^[^*]/, " &", $2); $1=""; print $0 }'
   else
-    printf "%s%s\\n" "error: index of plugins not found at " "$plugins_index_path"
+    printf "%s%s\n" "error: index of plugins not found at " "$plugins_index_path"
   fi
 }
 

lib/commands/command-plugin-push.bash

@@ -4,14 +4,14 @@ plugin_push_command() {
   local plugin_name=$1
   if [ "$plugin_name" = "--all" ]; then
     for dir in "$(asdf_data_dir)"/plugins/*/; do
-      printf "Pushing %s...\\n" "$(basename "$dir")"
+      printf "Pushing %s...\n" "$(basename "$dir")"
       (cd "$dir" && git push)
     done
   else
     local plugin_path
     plugin_path=$(get_plugin_path "$plugin_name")
     check_if_plugin_exists "$plugin_name"
-    printf "Pushing %s...\\n" "$plugin_name"
+    printf "Pushing %s...\n" "$plugin_name"
     (cd "$plugin_path" && git push)
   fi
 }

lib/commands/command-plugin-test.bash

@@ -53,7 +53,7 @@ plugin_test_command() {
   local TEST_DIR
 
   fail_test() {
-    printf "FAILED: %s\\n" "$1"
+    printf "FAILED: %s\n" "$1"
     rm -rf "$TEST_DIR"
     exit 1
   }
@@ -92,20 +92,20 @@ plugin_test_command() {
     local list_all="$plugin_path/bin/list-all"
     if grep api.github.com "$list_all" >/dev/null; then
       if ! grep Authorization "$list_all" >/dev/null; then
-        printf "\\nLooks like %s/bin/list-all relies on GitHub releases\\n" "$plugin_name"
+        printf "\nLooks like %s/bin/list-all relies on GitHub releases\n" "$plugin_name"
-        printf "but it does not properly sets an Authorization header to prevent\\n"
+        printf "but it does not properly sets an Authorization header to prevent\n"
-        printf "GitHub API rate limiting.\\n\\n"
+        printf "GitHub API rate limiting.\n\n"
-        printf "See https://github.com/asdf-vm/asdf/blob/master/docs/creating-plugins.md#github-api-rate-limiting\\n"
+        printf "See https://github.com/asdf-vm/asdf/blob/master/docs/creating-plugins.md#github-api-rate-limiting\n"
 
         fail_test "$plugin_name/bin/list-all does not set GitHub Authorization token"
       fi
 
       # test for most common token names we have on plugins. If both are empty show this warning
       if [ -z "$OAUTH_TOKEN" ] && [ -z "$GITHUB_API_TOKEN" ]; then
-        printf "%s/bin/list-all is using GitHub API, just be sure you provide an API Authorization token\\n" "$plugin_name"
+        printf "%s/bin/list-all is using GitHub API, just be sure you provide an API Authorization token\n" "$plugin_name"
-        printf "via your CI env GITHUB_API_TOKEN. This is the current rate_limit:\\n\\n"
+        printf "via your CI env GITHUB_API_TOKEN. This is the current rate_limit:\n\n"
         curl -s https://api.github.com/rate_limit
-        printf "\\n"
+        printf "\n"
       fi
     fi
 

lib/commands/command-update.bash

@@ -7,7 +7,7 @@ update_command() {
     cd "$(asdf_dir)" || exit 1
 
     if [ -f asdf_updates_disabled ] || ! git rev-parse --is-inside-work-tree &>/dev/null; then
-      printf "Update command disabled. Please use the package manager that you used to install asdf to upgrade asdf.\\n"
+      printf "Update command disabled. Please use the package manager that you used to install asdf to upgrade asdf.\n"
       exit 42
     else
       do_update "$update_to_head"
@@ -23,7 +23,7 @@ do_update() {
     git fetch origin master
     git checkout master
     git reset --hard origin/master
-    printf "Updated asdf to latest on the master branch\\n"
+    printf "Updated asdf to latest on the master branch\n"
   else
     # Update to latest release
     git fetch origin --tags || exit 1
@@ -38,7 +38,7 @@ do_update() {
 
     # Update
     git checkout "$tag" || exit 1
-    printf "Updated asdf to release %s\\n" "$tag"
+    printf "Updated asdf to release %s\n" "$tag"
   fi
 }
 

lib/commands/command-where.bash

@@ -34,14 +34,14 @@ where_command() {
   install_path=$(get_install_path "$plugin_name" "$install_type" "$version")
 
   if [ -d "$install_path" ]; then
-    printf "%s\\n" "$install_path"
+    printf "%s\n" "$install_path"
     exit 0
   else
     if [ "$version" = "system" ]; then
-      printf "System version is selected\\n"
+      printf "System version is selected\n"
       exit 1
     else
-      printf "Version not installed\\n"
+      printf "Version not installed\n"
       exit 1
     fi
   fi

lib/commands/command-which.bash

@@ -5,7 +5,7 @@ which_command() {
   shim_name=$(basename "$1")
 
   if [ -z "$shim_name" ]; then
-    printf "usage: asdf which <command>\\n"
+    printf "usage: asdf which <command>\n"
     exit 1
   fi
 
@@ -15,11 +15,11 @@ which_command() {
     local executable_path="$3"
 
     if [ ! -x "$executable_path" ]; then
-      printf "No %s executable found for %s %s\\n" "$shim_name" "$plugin_name" "$version" >&2
+      printf "No %s executable found for %s %s\n" "$shim_name" "$plugin_name" "$version" >&2
       exit 1
     fi
 
-    printf "%s\\n" "$executable_path"
+    printf "%s\n" "$executable_path"
     exit 0
   }
 

lib/commands/reshim.bash

@@ -142,10 +142,10 @@ remove_obsolete_shims() {
   # comm only takes to files, so we write this data to temp files so we can
   # pass it to comm.
   formatted_shims="$(mktemp "$temp_dir/asdf-command-reshim-formatted-shims.XXXXXX")"
-  printf "%s\\n" "$shims" >"$formatted_shims"
+  printf "%s\n" "$shims" >"$formatted_shims"
 
   formatted_exec_names="$(mktemp "$temp_dir/asdf-command-reshim-formatted-exec-names.XXXXXX")"
-  printf "%s\\n" "$exec_names" >"$formatted_exec_names"
+  printf "%s\n" "$exec_names" >"$formatted_exec_names"
 
   obsolete_shims=$(comm -23 "$formatted_shims" "$formatted_exec_names")
   rm -f "$formatted_exec_names" "$formatted_shims"

lib/functions/installs.bash

@@ -6,7 +6,7 @@ handle_failure() {
 
 handle_cancel() {
   local install_path="$1"
-  printf "\\nreceived sigint, cleaning up"
+  printf "\nreceived sigint, cleaning up"
   handle_failure "$install_path"
 }
 
@@ -32,7 +32,7 @@ get_concurrency() {
   elif [ -f /proc/cpuinfo ]; then
     grep -c processor /proc/cpuinfo
   else
-    printf "1\\n"
+    printf "1\n"
   fi
 }
 
@@ -55,7 +55,7 @@ install_one_local_tool() {
       install_tool_version "$plugin_name" "$plugin_version"
     done
   else
-    printf "No versions specified for %s in config files or environment\\n" "$plugin_name"
+    printf "No versions specified for %s in config files or environment\n" "$plugin_name"
     exit 1
   fi
 }
@@ -85,7 +85,7 @@ install_local_tool_versions() {
   fi
 
   if [ -z "$plugins_installed" ]; then
-    printf "Install plugins first to be able to install tools\\n"
+    printf "Install plugins first to be able to install tools\n"
     exit 1
   fi
 
@@ -122,9 +122,9 @@ install_local_tool_versions() {
   fi
 
   if [ -z "$some_tools_installed" ]; then
-    printf "Either specify a tool & version in the command\\n"
+    printf "Either specify a tool & version in the command\n"
-    printf "OR add .tool-versions file in this directory\\n"
+    printf "OR add .tool-versions file in this directory\n"
-    printf "or in a parent directory\\n"
+    printf "or in a parent directory\n"
     exit 1
   fi
 }
@@ -180,7 +180,7 @@ install_tool_version() {
   trap 'handle_cancel $install_path' INT
 
   if [ -d "$install_path" ]; then
-    printf "%s %s is already installed\\n" "$plugin_name" "$full_version"
+    printf "%s %s is already installed\n" "$plugin_name" "$full_version"
   else
 
     if [ -f "${plugin_path}/bin/download" ]; then

lib/functions/plugins.bash

@@ -28,7 +28,7 @@ plugin_list_command() {
         printf "%s" "$plugin_name"
 
         if [ -n "$show_repo" ]; then
-          printf "\\t%s" "$(git --git-dir "$plugin_path/.git" remote get-url origin 2>/dev/null)"
+          printf "\t%s" "$(git --git-dir "$plugin_path/.git" remote get-url origin 2>/dev/null)"
         fi
 
         if [ -n "$show_ref" ]; then
@@ -36,10 +36,10 @@ plugin_list_command() {
           local gitref
           branch=$(git --git-dir "$plugin_path/.git" rev-parse --abbrev-ref HEAD 2>/dev/null)
           gitref=$(git --git-dir "$plugin_path/.git" rev-parse --short HEAD 2>/dev/null)
-          printf "\\t%s\\t%s" "$branch" "$gitref"
+          printf "\t%s\t%s" "$branch" "$gitref"
         fi
 
-        printf "\\n"
+        printf "\n"
       done
     ) | awk '{ if (NF > 1) { printf("%-28s", $1) ; $1="" }; print $0}'
   else
@@ -145,7 +145,7 @@ update_plugin() {
     asdf_run_hook "pre_asdf_plugin_update" "$plugin_name"
     asdf_run_hook "pre_asdf_plugin_update_${plugin_name}"
 
-    printf "Updating %s to %s\\n" "$plugin_name" "$gitref"
+    printf "Updating %s to %s\n" "$plugin_name" "$gitref"
 
     git "${common_git_options[@]}" fetch --prune --update-head-ok origin "$gitref:$gitref"
     prev_ref=$(git "${common_git_options[@]}" rev-parse --short HEAD)

lib/functions/versions.bash

@@ -4,9 +4,9 @@ version_command() {
 
   if [ "$#" -lt "3" ]; then
     if [ "$cmd" = "global" ]; then
-      printf "Usage: asdf global <name> <version>\\n"
+      printf "Usage: asdf global <name> <version>\n"
     else
-      printf "Usage: asdf local <name> <version>\\n"
+      printf "Usage: asdf local <name> <version>\n"
     fi
     exit 1
   fi
@@ -68,7 +68,7 @@ version_command() {
     [[ -n "$(tail -c1 "$file")" && -f "$file" ]] && printf '\n' >>"$file"
 
     # Add a new version line to the end of the file
-    printf "%s %s\\n" "$plugin_name" "${resolved_versions[*]}" >>"$file"
+    printf "%s %s\n" "$plugin_name" "${resolved_versions[*]}" >>"$file"
   fi
 }
 
@@ -92,9 +92,9 @@ list_all_command() {
 
   if [[ $return_code -ne 0 ]]; then
     # Printing all output to allow plugin to handle error formatting
-    printf "Plugin %s's list-all callback script failed with output:\\n" "${plugin_name}" >&2
+    printf "Plugin %s's list-all callback script failed with output:\n" "${plugin_name}" >&2
-    printf "%s\\n" "$(cat "$std_err_file")" >&2
+    printf "%s\n" "$(cat "$std_err_file")" >&2
-    printf "%s\\n" "$(cat "$std_out_file")" >&2
+    printf "%s\n" "$(cat "$std_out_file")" >&2
     rm "$std_out_file" "$std_err_file"
     exit 1
   fi
@@ -115,7 +115,7 @@ list_all_command() {
   IFS=' ' read -r -a versions_list <<<"$output"
 
   for version in "${versions_list[@]}"; do
-    printf "%s\\n" "${version}"
+    printf "%s\n" "${version}"
   done
 
   # Remove temp files if they still exist
@@ -144,7 +144,7 @@ latest_command() {
     versions=$("${plugin_path}"/bin/latest-stable "$query")
     if [ -z "${versions}" ]; then
       # this branch requires this print to mimic the error from the list-all branch
-      printf "No compatible versions available (%s %s)\\n" "$plugin_name" "$query" >&2
+      printf "No compatible versions available (%s %s)\n" "$plugin_name" "$query" >&2
       exit 1
     fi
   else
@@ -158,7 +158,7 @@ latest_command() {
     fi
   fi
 
-  printf "%s\\n" "$versions"
+  printf "%s\n" "$versions"
 }
 
 latest_all() {
@@ -198,10 +198,10 @@ latest_all() {
       if [ -n "$installed_versions" ] && printf '%s\n' "$installed_versions" | grep -q "^$version\$"; then
         installed_status="installed"
       fi
-      printf "%s\\t%s\\t%s\\n" "$plugin_name" "$version" "$installed_status"
+      printf "%s\t%s\t%s\n" "$plugin_name" "$version" "$installed_status"
     done
   else
-    printf "%s\\n" 'No plugins installed'
+    printf "%s\n" 'No plugins installed'
   fi
   exit 0
 }

lib/utils.bash

@@ -13,9 +13,9 @@ asdf_version() {
   version="v$(cat "$(asdf_dir)/version.txt")"
   if [ -d "$(asdf_dir)/.git" ]; then
     git_rev="$(git --git-dir "$(asdf_dir)/.git" rev-parse --short HEAD)"
-    printf "%s-%s\\n" "$version" "$git_rev"
+    printf "%s-%s\n" "$version" "$git_rev"
   else
-    printf "%s\\n" "$version"
+    printf "%s\n" "$version"
   fi
 }
 
@@ -29,11 +29,11 @@ asdf_dir() {
     )
   fi
 
-  printf "%s\\n" "$ASDF_DIR"
+  printf "%s\n" "$ASDF_DIR"
 }
 
 asdf_repository_url() {
-  printf "https://github.com/asdf-vm/asdf-plugins.git\\n"
+  printf "https://github.com/asdf-vm/asdf-plugins.git\n"
 }
 
 asdf_data_dir() {
@@ -47,7 +47,7 @@ asdf_data_dir() {
     data_dir=$(asdf_dir)
   fi
 
-  printf "%s\\n" "$data_dir"
+  printf "%s\n" "$data_dir"
 }
 
 get_install_path() {
@@ -61,11 +61,11 @@ get_install_path() {
   mkdir -p "${install_dir}/${plugin}"
 
   if [ "$install_type" = "version" ]; then
-    printf "%s/%s/%s\\n" "$install_dir" "$plugin" "$version"
+    printf "%s/%s/%s\n" "$install_dir" "$plugin" "$version"
   elif [ "$install_type" = "path" ]; then
-    printf "%s\\n" "$version"
+    printf "%s\n" "$version"
   else
-    printf "%s/%s/%s-%s\\n" "$install_dir" "$plugin" "$install_type" "$version"
+    printf "%s/%s/%s-%s\n" "$install_dir" "$plugin" "$install_type" "$version"
   fi
 }
 
@@ -80,11 +80,11 @@ get_download_path() {
   mkdir -p "${download_dir}/${plugin}"
 
   if [ "$install_type" = "version" ]; then
-    printf "%s/%s/%s\\n" "$download_dir" "$plugin" "$version"
+    printf "%s/%s/%s\n" "$download_dir" "$plugin" "$version"
   elif [ "$install_type" = "path" ]; then
     return
   else
-    printf "%s/%s/%s-%s\\n" "$download_dir" "$plugin" "$install_type" "$version"
+    printf "%s/%s/%s-%s\n" "$download_dir" "$plugin" "$install_type" "$version"
   fi
 }
 
@@ -137,19 +137,19 @@ version_not_installed_text() {
   local plugin_name=$1
   local version=$2
 
-  printf "version %s is not installed for %s\\n" "$version" "$plugin_name"
+  printf "version %s is not installed for %s\n" "$version" "$plugin_name"
 }
 
 get_plugin_path() {
   if [ -n "$1" ]; then
-    printf "%s\\n" "$(asdf_data_dir)/plugins/$1"
+    printf "%s\n" "$(asdf_data_dir)/plugins/$1"
   else
-    printf "%s\\n" "$(asdf_data_dir)/plugins"
+    printf "%s\n" "$(asdf_data_dir)/plugins"
   fi
 }
 
 display_error() {
-  printf "%s\\n" "$1" >&2
+  printf "%s\n" "$1" >&2
 }
 
 get_version_in_dir() {
@@ -163,7 +163,7 @@ get_version_in_dir() {
   asdf_version=$(parse_asdf_version_file "$search_path/$file_name" "$plugin_name")
 
   if [ -n "$asdf_version" ]; then
-    printf "%s\\n" "$asdf_version|$search_path/$file_name"
+    printf "%s\n" "$asdf_version|$search_path/$file_name"
     return 0
   fi
 
@@ -172,7 +172,7 @@ get_version_in_dir() {
     legacy_version=$(parse_legacy_version_file "$search_path/$filename" "$plugin_name")
 
     if [ -n "$legacy_version" ]; then
-      printf "%s\\n" "$legacy_version|$search_path/$filename"
+      printf "%s\n" "$legacy_version|$search_path/$filename"
       return 0
     fi
   done
@@ -190,10 +190,10 @@ find_versions() {
   version=$(get_version_from_env "$plugin_name")
   if [ -n "$version" ]; then
     local upcase_name
-    upcase_name=$(printf "%s\\n" "$plugin_name" | tr '[:lower:]-' '[:upper:]_')
+    upcase_name=$(printf "%s\n" "$plugin_name" | tr '[:lower:]-' '[:upper:]_')
     local version_env_var="ASDF_${upcase_name}_VERSION"
 
-    printf "%s\\n" "$version|$version_env_var environment variable"
+    printf "%s\n" "$version|$version_env_var environment variable"
     return 0
   fi
 
@@ -212,7 +212,7 @@ find_versions() {
   while [ "$search_path" != "/" ]; do
     version=$(get_version_in_dir "$plugin_name" "$search_path" "$legacy_filenames")
     if [ -n "$version" ]; then
-      printf "%s\\n" "$version"
+      printf "%s\n" "$version"
       return 0
     fi
     search_path=$(dirname "$search_path")
@@ -223,7 +223,7 @@ find_versions() {
   if [ -f "$ASDF_DEFAULT_TOOL_VERSIONS_FILENAME" ]; then
     versions=$(parse_asdf_version_file "$ASDF_DEFAULT_TOOL_VERSIONS_FILENAME" "$plugin_name")
     if [ -n "$versions" ]; then
-      printf "%s\\n" "$versions|$ASDF_DEFAULT_TOOL_VERSIONS_FILENAME"
+      printf "%s\n" "$versions|$ASDF_DEFAULT_TOOL_VERSIONS_FILENAME"
       return 0
     fi
   fi
@@ -231,16 +231,16 @@ find_versions() {
 
 display_no_version_set() {
   local plugin_name=$1
-  printf "No version is set for %s; please run \`asdf <global | shell | local> %s <version>\`\\n" "$plugin_name" "$plugin_name"
+  printf "No version is set for %s; please run \`asdf <global | shell | local> %s <version>\`\n" "$plugin_name" "$plugin_name"
 }
 
 get_version_from_env() {
   local plugin_name=$1
   local upcase_name
-  upcase_name=$(printf "%s\\n" "$plugin_name" | tr '[:lower:]-' '[:upper:]_')
+  upcase_name=$(printf "%s\n" "$plugin_name" | tr '[:lower:]-' '[:upper:]_')
   local version_env_var="ASDF_${upcase_name}_VERSION"
   local version=${!version_env_var:-}
-  printf "%s\\n" "$version"
+  printf "%s\n" "$version"
 }
 
 find_install_path() {
@@ -251,7 +251,7 @@ find_install_path() {
   IFS=':' read -a version_info <<<"$version"
 
   if [ "$version" = "system" ]; then
-    printf "\\n"
+    printf "\n"
   elif [ "${version_info[0]}" = "ref" ]; then
     local install_type="${version_info[0]}"
     local version="${version_info[1]}"
@@ -263,7 +263,7 @@ find_install_path() {
     # And then use the binaries there
     local install_type="path"
     local version="path"
-    printf "%s\\n" "${version_info[1]}"
+    printf "%s\n" "${version_info[1]}"
   else
     local install_type="version"
     local version="${version_info[0]}"
@@ -281,12 +281,12 @@ get_custom_executable_path() {
     cmd=$(basename "$executable_path")
     local relative_path
     # shellcheck disable=SC2001
-    relative_path=$(printf "%s\\n" "$executable_path" | sed -e "s|${install_path}/||")
+    relative_path=$(printf "%s\n" "$executable_path" | sed -e "s|${install_path}/||")
     relative_path="$("${plugin_path}/bin/exec-path" "$install_path" "$cmd" "$relative_path")"
     executable_path="$install_path/$relative_path"
   fi
 
-  printf "%s\\n" "$executable_path"
+  printf "%s\n" "$executable_path"
 }
 
 get_executable_path() {
@@ -304,11 +304,11 @@ get_executable_path() {
     if [ $? -ne 0 ]; then
       return 1
     fi
-    printf "%s\\n" "$cmd_path"
+    printf "%s\n" "$cmd_path"
   else
     local install_path
     install_path=$(find_install_path "$plugin_name" "$version")
-    printf "%s\\n" "${install_path}"/"${executable_path}"
+    printf "%s\n" "${install_path}"/"${executable_path}"
   fi
 }
 
@@ -320,7 +320,7 @@ parse_asdf_version_file() {
     local version
     version=$(strip_tool_version_comments "$file_path" | grep "^${plugin_name} " | sed -e "s/^${plugin_name} //")
     if [ -n "$version" ]; then
-      printf "%s\\n" "$version"
+      printf "%s\n" "$version"
       return 0
     fi
   fi
@@ -353,7 +353,7 @@ get_preset_version_for() {
   local version
   version=$(cut -d '|' -f 1 <<<"$version_and_path")
 
-  printf "%s\\n" "$version"
+  printf "%s\n" "$version"
 }
 
 get_asdf_config_value_from_file() {
@@ -367,7 +367,7 @@ get_asdf_config_value_from_file() {
   local result
   result=$(grep -E "^\s*$key\s*=\s*" "$config_path" | head | sed -e 's/^[^=]*= *//' -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')
   if [ -n "$result" ]; then
-    printf "%s\\n" "$result"
+    printf "%s\n" "$result"
     return 0
   fi
 
@@ -414,7 +414,7 @@ initialize_or_update_repository() {
 
   disable_plugin_short_name_repo="$(get_asdf_config_value "disable_plugin_short_name_repository")"
   if [ "yes" == "$disable_plugin_short_name_repo" ]; then
-    printf "Short-name plugin repository is disabled\\n" >&2
+    printf "Short-name plugin repository is disabled\n" >&2
     exit 1
   fi
 
@@ -454,7 +454,7 @@ find_file_upwards() {
   search_path=$(pwd)
   while [ "$search_path" != "/" ]; do
     if [ -f "$search_path/$name" ]; then
-      printf "%s\\n" "${search_path}/$name"
+      printf "%s\n" "${search_path}/$name"
       return 0
     fi
     search_path=$(dirname "$search_path")
@@ -475,12 +475,12 @@ resolve_symlink() {
   # as relative
   case $resolved_path in
   /*)
-    printf "%s\\n" "$resolved_path"
+    printf "%s\n" "$resolved_path"
     ;;
   *)
     (
       cd "$(dirname "$symlink")" || exit 1
-      printf "%s\\n" "$PWD/$resolved_path"
+      printf "%s\n" "$PWD/$resolved_path"
     )
     ;;
   esac
@@ -508,7 +508,7 @@ list_plugin_bin_paths() {
   else
     local space_separated_list_of_bin_paths="bin"
   fi
-  printf "%s\\n" "$space_separated_list_of_bin_paths"
+  printf "%s\n" "$space_separated_list_of_bin_paths"
 }
 
 list_plugin_exec_paths() {
@@ -531,7 +531,7 @@ list_plugin_exec_paths() {
   local plugin_shims_path
   plugin_shims_path=$(get_plugin_path "$plugin_name")/shims
   if [ -d "$plugin_shims_path" ]; then
-    printf "%s\\n" "$plugin_shims_path"
+    printf "%s\n" "$plugin_shims_path"
   fi
 
   space_separated_list_of_bin_paths="$(list_plugin_bin_paths "$plugin_name" "$version" "$install_type")"
@@ -541,7 +541,7 @@ list_plugin_exec_paths() {
   install_path=$(get_install_path "$plugin_name" "$install_type" "$version")
 
   for bin_path in "${all_bin_paths[@]}"; do
-    printf "%s\\n" "$install_path/$bin_path"
+    printf "%s\n" "$install_path/$bin_path"
   done
 }
 
@@ -603,7 +603,7 @@ plugin_executables() {
   for bin_path in "${all_bin_paths[@]}"; do
     for executable_file in "$bin_path"/*; do
       if is_executable "$executable_file"; then
-        printf "%s\\n" "$executable_file"
+        printf "%s\n" "$executable_file"
       fi
     done
   done
@@ -631,7 +631,7 @@ shim_plugin_versions() {
   if [ -x "$shim_path" ]; then
     grep "# asdf-plugin: " "$shim_path" 2>/dev/null | sed -e "s/# asdf-plugin: //" | uniq
   else
-    printf "asdf: unknown shim %s\\n" "$executable_name"
+    printf "asdf: unknown shim %s\n" "$executable_name"
     return 1
   fi
 }
@@ -644,7 +644,7 @@ shim_plugins() {
   if [ -x "$shim_path" ]; then
     grep "# asdf-plugin: " "$shim_path" 2>/dev/null | sed -e "s/# asdf-plugin: //" | cut -d' ' -f 1 | uniq
   else
-    printf "asdf: unknown shim %s\\n" "$executable_name"
+    printf "asdf: unknown shim %s\n" "$executable_name"
     return 1
   fi
 }
@@ -682,7 +682,7 @@ get_shim_versions() {
 
 preset_versions() {
   shim_name=$1
-  shim_plugin_versions "${shim_name}" | cut -d' ' -f 1 | uniq | xargs -IPLUGIN bash -c ". $(asdf_dir)/lib/utils.bash; printf \"%s %s\\n\" PLUGIN \$(get_preset_version_for PLUGIN)"
+  shim_plugin_versions "${shim_name}" | cut -d' ' -f 1 | uniq | xargs -IPLUGIN bash -c ". $(asdf_dir)/lib/utils.bash; printf \"%s %s\n\" PLUGIN \$(get_preset_version_for PLUGIN)"
 }
 
 select_from_preset_version() {
@@ -693,7 +693,7 @@ select_from_preset_version() {
   shim_versions=$(get_shim_versions "$shim_name")
   if [ -n "$shim_versions" ]; then
     preset_versions=$(preset_versions "$shim_name")
-    grep -F "$shim_versions" <<<"$preset_versions" | head -n 1 | xargs -IVERSION printf "%s\\n" VERSION
+    grep -F "$shim_versions" <<<"$preset_versions" | head -n 1 | xargs -IVERSION printf "%s\n" VERSION
   fi
 }
 
@@ -728,10 +728,10 @@ select_version() {
         IFS=' ' read -r plugin_shim_name plugin_shim_version <<<"$plugin_and_version"
         if [[ "$plugin_name" == "$plugin_shim_name" ]]; then
           if [[ "$plugin_version" == "$plugin_shim_version" ]]; then
-            printf "%s\\n" "$plugin_name $plugin_version"
+            printf "%s\n" "$plugin_name $plugin_version"
             return
           elif [[ "$plugin_version" == "path:"* ]]; then
-            printf "%s\\n" "$plugin_name $plugin_version"
+            printf "%s\n" "$plugin_name $plugin_version"
             return
           fi
         fi
@@ -746,7 +746,7 @@ with_shim_executable() {
   local shim_exec="${2}"
 
   if [ ! -f "$(asdf_data_dir)/shims/${shim_name}" ]; then
-    printf "%s %s %s\\n" "unknown command:" "${shim_name}." "Perhaps you have to reshim?" >&2
+    printf "%s %s %s\n" "unknown command:" "${shim_name}." "Perhaps you have to reshim?" >&2
     return 1
   fi
 
@@ -803,15 +803,15 @@ with_shim_executable() {
     done
 
     if [ -n "${preset_plugin_versions[*]}" ]; then
-      printf "%s %s\\n" "No preset version installed for command" "$shim_name"
+      printf "%s %s\n" "No preset version installed for command" "$shim_name"
-      printf "%s\\n\\n" "Please install a version by running one of the following:"
+      printf "%s\n\n" "Please install a version by running one of the following:"
       for preset_plugin_version in "${preset_plugin_versions[@]}"; do
-        printf "%s %s\\n" "asdf install" "$preset_plugin_version"
+        printf "%s %s\n" "asdf install" "$preset_plugin_version"
       done
-      printf "\\n%s %s\\n" "or add one of the following versions in your config file at" "$closest_tool_version"
+      printf "\n%s %s\n" "or add one of the following versions in your config file at" "$closest_tool_version"
     else
-      printf "%s %s\\n" "No version is set for command" "$shim_name"
+      printf "%s %s\n" "No version is set for command" "$shim_name"
-      printf "%s %s\\n" "Consider adding one of the following versions in your config file at" "$closest_tool_version"
+      printf "%s %s\n" "Consider adding one of the following versions in your config file at" "$closest_tool_version"
     fi
     shim_plugin_versions "${shim_name}"
   ) >&2

scripts/checkstyle.py

@@ -0,0 +1,114 @@
+#!/usr/bin/env python3
+import re
+import sys
+import os
+import argparse
+from pathlib import Path
+from typing import List, Dict, Any # compat
+
+# This file checks Bash and Shell scripts for violations not found with
+# shellcheck or existing methods. You can use it in several ways:
+#
+# Lint all .bash, .sh, and .bats files and print out violations
+# $ ./scripts/checkstyle.py
+#
+# The former, but also fix all violations. This must be ran until there
+# are zero violations since any line can have more than one violation
+# $ ./scripts/checkstyle.py --fix
+#
+# Lint a particular file
+# $ ./scripts/checkstyle.py ./lib/functions/installs.bash
+
+class c:
+    RED = '\033[91m'
+    GREEN = '\033[92m'
+    YELLOW = '\033[93m'
+    BLUE = '\033[94m'
+    MAGENTA = '\033[95m'
+    CYAN = '\033[96m'
+    RESET = '\033[0m'
+    BOLD = '\033[1m'
+    UNDERLINE = '\033[4m'
+
+# Before: printf '%s\\n' '^w^'
+# After: printf '%s\n' '^w^'
+def noDoubleBackslashFixer(line: str, rule: Dict[str, str], m: re.Match[str]) -> str:
+    prestr = line[0:m.start('match')]
+    midstr = line[m.start('match'):m.end('match')]
+    poststr = line[m.end('match'):]
+
+    fixed_line = f'{prestr}{midstr[1:]}{poststr}'
+    return fixed_line
+
+def lintfile(filepath: Path, rules: List[Dict[str, str]], options: Dict[str, Any]):
+    content_arr = filepath.read_text().split('\n')
+
+    for line_i, line in enumerate(content_arr):
+        for rule in rules:
+            m = re.search(rule['regex'], line)
+            if m is not None and m.group('match') is not None:
+                dir = os.path.relpath(filepath.resolve(), Path.cwd())
+                prestr = line[0:m.start('match')]
+                midstr = line[m.start('match'):m.end('match')]
+                poststr = line[m.end('match'):]
+
+                print(f'{c.CYAN}{dir}{c.RESET}:{line_i + 1}')
+                print(f'{c.MAGENTA}{rule["name"]}{c.RESET}: {rule["reason"]}')
+                print(f'{prestr}{c.RED}{midstr}{c.RESET}{poststr}')
+                print()
+
+                if options['fix']:
+                    content_arr[line_i] = rule['fixer_fn'](line, rule, m)
+
+                rule['found'] += 1
+
+    if options['fix']:
+        filepath.write_text('\n'.join(content_arr))
+
+def main():
+    rules = [
+        {
+            'name': 'no-double-backslash',
+            'regex': '".*?(?P<match>\\\\\\\\[abeEfnrtv\'"?xuUc]).*?(?<!\\\\)"',
+            'reason': 'Backslashes are only required if followed by a $, `, ", \\, or <newline>',
+            'fixer_fn': noDoubleBackslashFixer,
+            'found': 0
+        },
+    ]
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('files', metavar='FILES', nargs='*')
+    parser.add_argument('--fix', action='store_true')
+    args = parser.parse_args()
+
+    options = {
+        'fix': args.fix
+    }
+
+    # parse files and print matched lints
+    if len(args.files) > 0:
+        for file in args.files:
+            p = Path(file)
+            if p.is_file():
+                lintfile(p, rules, options)
+    else:
+        for file in Path.cwd().glob('**/*'):
+            if file.name.endswith('.bash') or file.name.endswith('.sh') or file.name.endswith('.bats'):
+                if file.is_file():
+                    lintfile(file, rules, options)
+
+    # print final results
+    print(f'{c.UNDERLINE}TOTAL ISSUES{c.RESET}')
+    for rule in rules:
+        print(f'{c.MAGENTA}{rule["name"]}{c.RESET}: {rule["found"]}')
+
+    grand_total = sum([rule['found'] for rule in rules])
+    print(f'GRAND TOTAL: {grand_total}')
+
+    # exit
+    if grand_total == 0:
+        exit(0)
+    else:
+        exit(2)
+
+main()