diff --git a/bin/asdf b/bin/asdf
index 4a15f61f0..351d93848 100755
--- a/bin/asdf
+++ b/bin/asdf
@@ -63,7 +63,7 @@ asdf_cmd() {
   local ASDF_CMD_FILE args_offset
 
   if [ "shell" = "$1" ]; then
-    printf "Shell integration is not enabled. Please ensure you source asdf in your shell setup." >&2
+    display_error "Shell integration is not enabled. Please ensure you source asdf in your shell setup."
     exit 1
   fi
 
@@ -96,12 +96,12 @@ asdf_cmd() {
     # In those cases, the path to that command is always an absolute path. However, this codepath can also be activated if a user accidentally
     # marks files in ./lib/commands/* as executable. This code detects when that happens and prints a useful warning message.
     if [[ "$ASDF_CMD_FILE" == ./lib/commands/* ]]; then
-      printf '%s\n' "----------"
-      printf '%s\n' "asdf: Warning: You are executing an asdf command from \$ASDF_DIR, but we detected that some files have been"
-      printf '%s\n' "               erroneously marked as executable. All files under '$ASDF_DIR/lib/commands' must NOT be marked"
-      printf '%s\n' "               as executable. Otherwise, asdf will not be able to source its core files"
-      printf '%s\n' "----------"
-    fi >&2
+      display_error "----------"
+      display_error "asdf: Warning: You are executing an asdf command from \$ASDF_DIR, but we detected that some files have been"
+      display_error "               erroneously marked as executable. All files under '$ASDF_DIR/lib/commands' must NOT be marked"
+      display_error "               as executable. Otherwise, asdf will not be able to source its core files"
+      display_error "----------"
+    fi
 
     exec "$ASDF_CMD_FILE" "${@:${args_offset}}"
   elif [ -f "$ASDF_CMD_FILE" ]; then
@@ -111,7 +111,7 @@ asdf_cmd() {
   else
     local asdf_cmd_dir
     asdf_cmd_dir="$(asdf_dir)/lib/commands"
-    printf "%s\n" "Unknown command: \`asdf ${*}\`" >&2
+    display_error "Unknown command: \`asdf ${*}\`"
     # shellcheck source=lib/commands/command-help.bash
     . "$asdf_cmd_dir/command-help.bash" >&2
     return 127
diff --git a/lib/commands/command-current.bash b/lib/commands/command-current.bash
index f4724626e..1684c5241 100644
--- a/lib/commands/command-current.bash
+++ b/lib/commands/command-current.bash
@@ -30,15 +30,15 @@ plugin_current_command() {
 
   if [ -n "$version_not_installed" ]; then
     description="Not installed. Run \"asdf install $plugin $version\""
-    printf "$terminal_format" "$plugin" "$version" "$description" 1>&2
+    display_error "$terminal_format" "$plugin" "$version" "$description"
     return 1
   elif [ -z "$full_version" ]; then
     description="No version is set. Run \"asdf <global|shell|local> $plugin <version>\""
-    printf "$terminal_format" "$plugin" "______" "$description" 1>&2
+    display_error "$terminal_format" "$plugin" "______" "$description"
     return 126
   else
     description="$version_file_path"
-    printf "$terminal_format" "$plugin" "$full_version" "$description"
+    display_info "$terminal_format" "$plugin" "$full_version" "$description"
   fi
 }
 
@@ -48,7 +48,7 @@ current_command() {
   local exit_status=0
   local plugin
 
-  # printf "$terminal_format" "PLUGIN" "VERSION" "SET BY CONFIG" # disable this until we release headings across the board
+  # printf "$terminal_format" "PLUGIN" "VERSION" "SET BY CONFIG" # TODO: disable this until we release headings across the board
   if [ $# -eq 0 ]; then
     # shellcheck disable=SC2119
     for plugin in $(plugin_list_command); do
@@ -75,8 +75,8 @@ check_for_deprecated_plugin() {
   local new_script="${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 "  asdf plugin-update %s\n\n" "$plugin_name"
+    display_info "Heads up! It looks like your %s plugin is out of date. You can update it with:\n\n" "$plugin_name"
+    display_info "  asdf plugin-update %s\n\n" "$plugin_name"
   fi
 }
 
diff --git a/lib/commands/command-exec.bash b/lib/commands/command-exec.bash
index cb56b36c3..0e226f4f5 100644
--- a/lib/commands/command-exec.bash
+++ b/lib/commands/command-exec.bash
@@ -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
+      display_error "No %s executable found for %s %s\n" "$shim_name" "$plugin_name" "$version"
       exit 2
     fi
 
diff --git a/lib/commands/command-export-shell-version.bash b/lib/commands/command-export-shell-version.bash
index 92ace8abe..605435152 100644
--- a/lib/commands/command-export-shell-version.bash
+++ b/lib/commands/command-export-shell-version.bash
@@ -8,7 +8,7 @@ shell_command() {
   shift
 
   if [ "$#" -lt "2" ]; then
-    printf "Usage: asdf shell <name> {<version>|--unset}\n" >&2
+    display_error "Usage: asdf shell <name> {<version>|--unset}\n"
     printf "false\n"
     exit 1
   fi
@@ -44,7 +44,7 @@ shell_command() {
     version=$(latest_command "$plugin")
   fi
   if ! (check_if_version_exists "$plugin" "$version"); then
-    version_not_installed_text "$plugin" "$version" 1>&2
+    display_version_not_installed "$plugin" "$version" >&2
     printf "false\n"
     exit 1
   fi
diff --git a/lib/commands/command-help.bash b/lib/commands/command-help.bash
index 77f1bb27c..2e547dc13 100644
--- a/lib/commands/command-help.bash
+++ b/lib/commands/command-help.bash
@@ -78,11 +78,11 @@ help_command() {
           (print_plugin_help "$plugin_path")
         fi
       else
-        printf "No documentation for plugin %s\n" "$plugin_name" >&2
+        display_error "No documentation for plugin %s\n" "$plugin_name"
         exit 1
       fi
     else
-      printf "No plugin named %s\n" "$plugin_name" >&2
+      display_error "No plugin named %s\n" "$plugin_name"
       exit 1
     fi
   else
diff --git a/lib/commands/command-update.bash b/lib/commands/command-update.bash
index f9912645f..b5bc20807 100644
--- a/lib/commands/command-update.bash
+++ b/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"
+      display_info "Update command disabled. Please use the package manager that you used to install asdf to upgrade asdf."
       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"
+    display_info "Updated asdf to latest on the master branch"
   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"
+    display_info "Updated asdf to release %s\n" "$tag"
   fi
 }
 
diff --git a/lib/commands/command-which.bash b/lib/commands/command-which.bash
index 8696dbf3e..786bf6aaf 100644
--- a/lib/commands/command-which.bash
+++ b/lib/commands/command-which.bash
@@ -15,7 +15,7 @@ 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
+      display_error "No %s executable found for %s %s\n" "$shim_name" "$plugin_name" "$version"
       exit 1
     fi
 
diff --git a/lib/functions/installs.bash b/lib/functions/installs.bash
index 721ae50c4..54e16433b 100644
--- a/lib/functions/installs.bash
+++ b/lib/functions/installs.bash
@@ -67,7 +67,7 @@ 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" "$plugin_name"
+    display_info "No versions specified for %s in config files or environment\n" "$plugin_name"
     exit 1
   fi
 }
@@ -97,7 +97,7 @@ install_local_tool_versions() {
   fi
 
   if [ -z "$plugins_installed" ]; then
-    printf "Install plugins first to be able to install tools\n"
+    display_info "Install plugins first to be able to install tools"
     exit 1
   fi
 
@@ -107,7 +107,7 @@ install_local_tool_versions() {
     tools_file=$(strip_tool_version_comments "$tool_versions_path" | cut -d ' ' -f 1)
     for plugin_name in $tools_file; do
       if ! printf '%s\n' "${plugins_installed[@]}" | grep -q "^$plugin_name\$"; then
-        printf "%s plugin is not installed\n" "$plugin_name"
+        display_info "%s plugin is not installed\n" "$plugin_name"
         some_plugin_not_installed='yes'
       fi
     done
@@ -134,9 +134,9 @@ install_local_tool_versions() {
   fi
 
   if [ -z "$some_tools_installed" ]; then
-    printf "Either specify a tool & version in the command\n"
-    printf "OR add .tool-versions file in this directory\n"
-    printf "or in a parent directory\n"
+    display_info "Either specify a tool & version in the command"
+    display_info "OR add .tool-versions file in this directory"
+    display_info "or in a parent directory"
     exit 1
   fi
 }
@@ -192,7 +192,7 @@ install_tool_version() {
   trap 'handle_cancel $install_path' INT
 
   if [ -d "$install_path" ]; then
-    printf "%s %s is already installed\n" "$plugin_name" "$full_version"
+    display_info "%s %s is already installed\n" "$plugin_name" "$full_version"
   else
 
     if [ -f "${plugin_path}/bin/download" ]; then
diff --git a/lib/functions/plugins.bash b/lib/functions/plugins.bash
index 3b36ddd9c..5f7c1fdcb 100644
--- a/lib/functions/plugins.bash
+++ b/lib/functions/plugins.bash
@@ -79,7 +79,7 @@ plugin_add_command() {
   mkdir -p "$(asdf_data_dir)/plugins"
 
   if [ -d "$plugin_path" ]; then
-    printf '%s\n' "Plugin named $plugin_name already added"
+    display_info "Plugin named $plugin_name already added"
     exit 0
   else
     asdf_run_hook "pre_asdf_plugin_add" "$plugin_name"
@@ -140,11 +140,11 @@ update_plugin() {
   local prev_ref=
   local post_ref=
   {
-    printf "Location of %s plugin: %s\n" "$plugin_name" "$plugin_path"
+    display_info "Location of %s plugin: %s\n" "$plugin_name" "$plugin_path"
     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"
+    display_info "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)
diff --git a/lib/functions/versions.bash b/lib/functions/versions.bash
index 4b7cc34bc..185e8f749 100644
--- a/lib/functions/versions.bash
+++ b/lib/functions/versions.bash
@@ -53,7 +53,7 @@ version_command() {
     fi
 
     if ! (check_if_version_exists "$plugin_name" "$version"); then
-      version_not_installed_text "$plugin_name" "$version" 1>&2
+      display_version_not_installed "$plugin_name" "$version" >&2
       exit 1
     fi
 
@@ -99,9 +99,9 @@ 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 "%s\n" "$(cat "$std_err_file")" >&2
-    printf "%s\n" "$(cat "$std_out_file")" >&2
+    display_error "Plugin %s's list-all callback script failed with output:\n" "${plugin_name}"
+    display_error "%s\n" "$(cat "$std_err_file")"
+    display_error "%s\n" "$(cat "$std_out_file")"
     rm "$std_out_file" "$std_err_file"
     exit 1
   fi
@@ -151,7 +151,7 @@ latest_command() {
     versions=$("${plugin_path}"/bin/latest-stable "$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" "$query" >&2
+      display_error "No compatible versions available (%s %s)\n" "$plugin_name" "$query"
       exit 1
     fi
   else
@@ -208,7 +208,7 @@ latest_all() {
       printf "%s\t%s\t%s\n" "$plugin_name" "$version" "$installed_status"
     done
   else
-    printf "%s\n" 'No plugins installed'
+    display_info 'No plugins installed'
   fi
   exit 0
 }
diff --git a/lib/utils.bash b/lib/utils.bash
index 8eae18fcb..7439f5ba7 100644
--- a/lib/utils.bash
+++ b/lib/utils.bash
@@ -137,13 +137,6 @@ check_if_version_exists() {
   fi
 }
 
-version_not_installed_text() {
-  local plugin_name=$1
-  local version=$2
-
-  printf "version %s is not installed for %s\n" "$version" "$plugin_name"
-}
-
 get_plugin_path() {
   if [ -n "$1" ]; then
     printf "%s\n" "$(asdf_data_dir)/plugins/$1"
@@ -153,7 +146,33 @@ get_plugin_path() {
 }
 
 display_error() {
-  printf "%s\n" "$1" >&2
+  if (($# == 1)); then
+    set -- '%s\n' "$@"
+  fi
+
+  # shellcheck disable=SC2059
+  printf "$@" >&2 # checkstyle-ignore
+}
+
+display_info() {
+  if (($# == 1)); then
+    set -- '%s\n' "$@"
+  fi
+
+  # shellcheck disable=SC2059
+  printf "$@"
+}
+
+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"
+}
+
+display_version_not_installed() {
+  local plugin_name=$1
+  local version=$2
+
+  printf "version %s is not installed for %s\n" "$version" "$plugin_name"
 }
 
 get_version_in_dir() {
@@ -229,11 +248,6 @@ find_versions() {
   fi
 }
 
-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"
-}
-
 get_version_from_env() {
   local plugin_name=$1
   local upcase_name
@@ -426,7 +440,7 @@ initialize_or_update_plugin_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
+    display_error "Short-name plugin repository is disabled"
     exit 1
   fi
 
@@ -646,7 +660,7 @@ 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" "$executable_name"
+    display_info "asdf: unknown shim %s\n" "$executable_name"
     return 1
   fi
 }
@@ -659,7 +673,7 @@ 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" "$executable_name"
+    display_info "asdf: unknown shim %s\n" "$executable_name"
     return 1
   fi
 }
@@ -761,7 +775,7 @@ with_shim_executable() {
   local shim_exec="${2}"
 
   if [ ! -f "$(asdf_data_dir)/shims/${shim_name}" ]; then
-    printf "%s %s %s\n" "unknown command:" "${shim_name}." "Perhaps you have to reshim?" >&2
+    display_error "%s %s %s\n" "unknown command:" "${shim_name}." "Perhaps you have to reshim?"
     return 1
   fi
 
@@ -820,15 +834,15 @@ with_shim_executable() {
     done
 
     if [ -n "${preset_plugin_versions[*]}" ]; then
-      printf "%s %s\n" "No preset version installed for command" "$shim_name"
-      printf "%s\n\n" "Please install a version by running one of the following:"
+      display_info "%s %s\n" "No preset version installed for command" "$shim_name"
+      display_info "%s\n\n" "Please install a version by running one of the following:"
       for preset_plugin_version in "${preset_plugin_versions[@]}"; do
-        printf "%s %s\n" "asdf install" "$preset_plugin_version"
+        display_info "%s %s\n" "asdf install" "$preset_plugin_version"
       done
-      printf "\n%s %s\n" "or add one of the following versions in your config file at" "$closest_tool_version"
+      display_info "\n%s %s\n" "or add one of the following versions in your config file at" "$closest_tool_version"
     else
-      printf "%s %s\n" "No version is set for command" "$shim_name"
-      printf "%s %s\n" "Consider adding one of the following versions in your config file at" "$closest_tool_version"
+      display_info "%s %s\n" "No version is set for command" "$shim_name"
+      display_info "%s %s\n" "Consider adding one of the following versions in your config file at" "$closest_tool_version"
     fi
     shim_plugin_versions "${shim_name}"
   ) >&2
@@ -872,7 +886,7 @@ util_validate_no_carriage_returns() {
   local file_path="$1"
 
   if grep -qr $'\r' "$file_path"; then
-    printf '%s\n' "asdf: Warning: File $file_path contains carriage returns. Please remove them." >&2
+    display_error "asdf: Warning: File $file_path contains carriage returns. Please remove them."
   fi
 }
 
diff --git a/scripts/checkstyle.py b/scripts/checkstyle.py
index 28294ea0b..9e5713b39 100755
--- a/scripts/checkstyle.py
+++ b/scripts/checkstyle.py
@@ -35,7 +35,7 @@ class c:
     UNDERLINE = '\033[4m'
     LINK: Callable[[str, str], str] = lambda href, text: f'\033]8;;{href}\a{text}\033]8;;\a'
 
-def utilGetStrs(line: Any, m: Any):
+def utilGetStrs(line: str, m: Any):
     return (
         line[0:m.start('match')],
         line[m.start('match'):m.end('match')],
@@ -90,6 +90,42 @@ def noVerboseRedirectionFixer(line: str, m: Any) -> str:
 
     return f'{prestr}&>/dev/null{poststr}'
 
+def noExplicitStandardOutputRedirectionFixer(line: str, m: Any) -> str:
+    prestr, _, poststr = utilGetStrs(line, m)
+
+    return f'{prestr}>&2{poststr}'
+
+# Before: printf '%s\n' 'text' >&2
+# After: display_error 'text'
+def noPrintfStandardErrorFixer(line: str, m: Any) -> str:
+    prestr, _, poststr = utilGetStrs(line, m)
+
+    poststr = poststr.rstrip()
+    if poststr.endswith('>&2'): # str.removesuffix Python 3.9
+        poststr = poststr[0:len(poststr)-len('>&2')]
+    poststr = poststr.rstrip()
+
+    return f'{prestr}display_error{poststr}'
+
+# Before: display_info 'text\n'
+# After: display_info 'text'
+def noDisplayFnNewlineFixer(line: str, m: Any) -> str:
+    prestr, midstr, poststr = utilGetStrs(line, m)
+
+    midstr = midstr.removesuffix('\\n')
+
+    return f'{prestr}{midstr}{poststr}'
+
+# Before: display_info '%s\n' 'text'
+# After: display_info 'text'
+def noDisplayFnFormattingArgFixer(line: str, m: Any) -> str:
+    prestr, _, poststr = utilGetStrs(line, m)
+
+    prestr = prestr.rstrip()
+    poststr = poststr.lstrip()
+
+    return f'{prestr} {poststr}'
+
 def lintfile(file: Path, rules: List[Rule], options: Dict[str, Any]):
     content_arr = file.read_text().split('\n')
 
@@ -106,6 +142,13 @@ def lintfile(file: Path, rules: List[Rule], options: Dict[str, Any]):
                 if file.name.endswith('.bash') or file.name.endswith('.bats'):
                     should_run = True
 
+            if 'matchesIgnored' in rule:
+                for glb in rule['matchesIgnored']:
+                    if file.match(glb):
+                        should_run = False
+                        break
+
+
             if options['verbose']:
                 print(f'{str(file)}: {should_run}')
 
@@ -142,11 +185,15 @@ def main():
             'fixerFn': noDoubleBackslashFixer,
             'testPositiveMatches': [
                 'printf "%s\\\\n" "Hai"',
-                'echo -n "Hello\\\\n"'
+                'echo -n "Hello\\\\n"',
+            ],
+            'testPositiveMatchesFixed': [
+                'printf "%s\\n" "Hai"',
+                'echo -n "Hello\\n"',
             ],
             'testNegativeMatches': [
                 'printf "%s\\n" "Hai"',
-                'echo -n "Hello\\n"'
+                'echo -n "Hello\\n"',
             ],
         },
         {
@@ -156,10 +203,13 @@ def main():
             'fileTypes': ['bash', 'sh'],
             'fixerFn': noPwdCaptureFixer,
             'testPositiveMatches': [
-                '$(pwd)'
+                '$(pwd)',
+            ],
+            'testPositiveMatchesFixed': [
+                '$PWD',
             ],
             'testNegativeMatches': [
-                '$PWD'
+                '$PWD',
             ],
         },
         {
@@ -172,6 +222,10 @@ def main():
                 '[ a == b ]',
                 '[ "${lines[0]}" == blah ]',
             ],
+            'testPositiveMatchesFixed': [
+                '[ a = b ]',
+                '[ "${lines[0]}" = blah ]',
+            ],
             'testNegativeMatches': [
                 '[ a = b ]',
                 '[[ a = b ]]',
@@ -189,8 +243,12 @@ def main():
             'fileTypes': ['bash', 'sh'],
             'fixerFn': noFunctionKeywordFixer,
             'testPositiveMatches': [
-                'function fn() { :; }',
-                'function fn { :; }',
+                'function fn1() { :; }',
+                'function fn2 { :; }',
+            ],
+            'testPositiveMatchesFixed': [
+                'fn1() { :; }',
+                'fn2() { :; }',
             ],
             'testNegativeMatches': [
                 'fn() { :; }',
@@ -203,14 +261,92 @@ def main():
             'fileTypes': ['bash'],
             'fixerFn': noVerboseRedirectionFixer,
             'testPositiveMatches': [
-                'echo woof >/dev/null 2>&1',
-                'echo woof 2>/dev/null 1>&2',
+                'echo woof1 >/dev/null 2>&1',
+                'echo woof2 2>/dev/null 1>&2',
+            ],
+            'testPositiveMatchesFixed': [
+                'echo woof1 &>/dev/null',
+                'echo woof2 &>/dev/null',
             ],
             'testNegativeMatches': [
                 'echo woof &>/dev/null',
                 'echo woof >&/dev/null',
             ],
         },
+        {
+            'name': 'no-explicit-stdout-redirection',
+            'regex': '(?P<match>1>&2)',
+            'reason': 'For consistency and to support less complex linters',
+            'fileTypes': ['bash', 'sh'],
+            'fixerFn': noExplicitStandardOutputRedirectionFixer,
+            'testPositiveMatches': [
+                'echo blah 1>&2',
+            ],
+            'testPositiveMatchesFixed': [
+                'echo blah >&2',
+            ],
+            'testNegativeMatches': [
+                'echo blah >&2',
+            ],
+        },
+        {
+            'name': 'no-printf-standard-error',
+            'regex': '(?P<match>display_info|printf|echo).*(?P<r>>&2)',
+            'reason': 'Use `display_error`, which has shared semantics and logic',
+            'fileTypes': ['bash', 'sh'],
+            'matchesIgnored': ['scripts/*', 'asdf.sh'],
+            'fixerFn': noPrintfStandardErrorFixer,
+            'testPositiveMatches': [
+                'printf "text1" >&2',
+                "echo 'text2' >&2",
+                'display_info text4 >&2',
+            ],
+            'testPositiveMatchesFixed': [
+                'display_error "text1"',
+                "display_error 'text2'",
+                "display_error text4",
+            ],
+            'testNegativeMatches': [
+                'echo woah1',
+                'echo woah2',
+                '>&2 printf text3',
+            ],
+        },
+        {
+            'name': 'no-display-fn-newline',
+            'regex': 'display_info[ \\t]+[\'"](?P<match>.*?\\\\n)[\'"][ \\t]*$',
+            'reason': 'Function `display_info` already prints a newline',
+            'fileTypes': ['bash', 'sh'],
+            'fixerFn': noDisplayFnNewlineFixer,
+            'testPositiveMatches': [
+                'display_info "a\\n"',
+                "display_info 'b\\n'",
+            ],
+            'testPositiveMatchesFixed': [
+                'display_info "a"',
+                "display_info 'b'",
+            ],
+            'testNegativeMatches': [
+                'display_info c',
+                'display_info "\\nd"'
+            ],
+        },
+        {
+            'name': 'no-display-formatting-arg',
+            'regex': 'display_info[ \\t]+(?P<match>[\'"]%s\\\\n[\'"])',
+            'reason': 'Function `display_info` already prints a newline',
+            'fileTypes': ['bash', 'sh'],
+            'fixerFn': noDisplayFnFormattingArgFixer,
+            'testPositiveMatches': [
+                'display_info "%s\\n" other',
+            ],
+            'testPositiveMatchesFixed': [
+                'display_info other',
+            ],
+            'testNegativeMatches': [
+                'display_info "%s\\n\\n"',
+            ],
+        },
     ]
     [rule.update({ 'found': 0 }) for rule in rules]
 
@@ -223,12 +359,24 @@ def main():
 
     if args.internal_test_regex:
         for rule in rules:
-            for positiveMatch in rule['testPositiveMatches']:
+            for (i, positiveMatch) in enumerate(rule['testPositiveMatches']):
                 m: Any = re.search(rule['regex'], positiveMatch)
                 if m is None or m.group('match') is None:
                     print(f'{c.MAGENTA}{rule["name"]}{c.RESET}: Failed {c.CYAN}positive{c.RESET} test:')
                     print(f'=> {positiveMatch}')
-                    print()
+                    exit(1)
+
+                if len(rule['testPositiveMatchesFixed']) < len(rule['testPositiveMatches']):
+                    print(f'{c.MAGENTA}{rule["name"]}{c.RESET}: Failed {c.BLUE}fixer preliminary{c.RESET} test:')
+                    print(f'=> Missing items in array: testPositiveMatchesFixed')
+                    exit(1)
+
+                fixedLine = rule['fixerFn'](positiveMatch, m)
+                if rule['testPositiveMatchesFixed'][i] != fixedLine:
+                    print(f'{c.MAGENTA}{rule["name"]}{c.RESET}: Failed {c.BLUE}fixer{c.RESET} test:')
+                    print(f'=> expected: {rule["testPositiveMatchesFixed"][i]}')
+                    print(f'=> received: {fixedLine}')
+                    exit(1)
 
             for negativeMatch in rule['testNegativeMatches']:
                 m: Any = re.search(rule['regex'], negativeMatch)
diff --git a/scripts/install_dependencies.bash b/scripts/install_dependencies.bash
index 8965077d7..9904f6bdc 100755
--- a/scripts/install_dependencies.bash
+++ b/scripts/install_dependencies.bash
@@ -35,7 +35,7 @@ if [ "$RUNNER_OS" = "Linux" ]; then
   printf "%s\n" "Installing dependencies on Linux"
 
   curl -fsSLo- https://packages.microsoft.com/keys/microsoft.asc | sudo tee /etc/apt/trusted.gpg.d/microsoft.asc >/dev/null
-  sudo sh -c 'echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-debian-bullseye-prod bullseye main" > /etc/apt/sources.list.d/microsoft.list'
+  sudo sh -c 'printf "%s\n" "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-debian-bullseye-prod bullseye main" > /etc/apt/sources.list.d/microsoft.list'
   sudo add-apt-repository -y ppa:fish-shell/release-3
   sudo apt-get update
   sudo apt-get -y install curl parallel \
@@ -58,7 +58,7 @@ if [ "$RUNNER_OS" = "Linux" ]; then
   mv nu-${nushell_semver}-x86_64-unknown-linux-gnu/* "$HOME/bin"
 
   # Add $HOME/bin to path (add Elvish & Nushell to path)
-  echo "$HOME/bin" >>"$GITHUB_PATH"
+  printf '%s\n' "$HOME/bin" >>"$GITHUB_PATH"
 fi
 
 ### Install dependencies on macOS
@@ -75,4 +75,4 @@ fi
 printf "%s\n" "Installing bats-core"
 bats_version=$(grep -Eo "^\\s*bats\\s*.*$" ".tool-versions" | cut -d ' ' -f2-)
 git clone --depth 1 --branch "v$bats_version" https://github.com/bats-core/bats-core.git "$HOME/bats-core"
-echo "$HOME/bats-core/bin" >>"$GITHUB_PATH"
+printf '%s\n' "$HOME/bats-core/bin" >>"$GITHUB_PATH"
diff --git a/test/utils.bats b/test/utils.bats
index 39f29ebac..a1f0dd66f 100644
--- a/test/utils.bats
+++ b/test/utils.bats
@@ -70,8 +70,8 @@ teardown() {
   [ "$status" -eq 1 ]
 }
 
-@test "version_not_installed_text is correct" {
-  run version_not_installed_text "dummy" "1.0.0"
+@test "display_version_not_installed is correct" {
+  run display_version_not_installed "dummy" "1.0.0"
   [ "$status" -eq 0 ]
   [ "$output" = "version 1.0.0 is not installed for dummy" ]
 }