From db8639fcfd00ebb2c37a5c0a6acb9d17baa232bf Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Sat, 12 Sep 2026 13:46:56 +0200
Subject: [PATCH 1/6] Generated exercice files with `configlet create`

---
 config.json                                   |  8 ++++
 .../save-the-cow/.docs/instructions.md        |  7 ++++
 .../save-the-cow/.docs/introduction.md        |  4 ++
 .../practice/save-the-cow/.meta/config.json   | 15 +++++++
 .../practice/save-the-cow/.meta/example.sh    |  0
 .../practice/save-the-cow/.meta/tests.toml    | 40 +++++++++++++++++++
 .../practice/save-the-cow/save_the_cow.bats   |  0
 .../practice/save-the-cow/save_the_cow.sh     |  0
 8 files changed, 74 insertions(+)
 create mode 100644 exercises/practice/save-the-cow/.docs/instructions.md
 create mode 100644 exercises/practice/save-the-cow/.docs/introduction.md
 create mode 100644 exercises/practice/save-the-cow/.meta/config.json
 create mode 100644 exercises/practice/save-the-cow/.meta/example.sh
 create mode 100644 exercises/practice/save-the-cow/.meta/tests.toml
 create mode 100644 exercises/practice/save-the-cow/save_the_cow.bats
 create mode 100644 exercises/practice/save-the-cow/save_the_cow.sh

diff --git a/config.json b/config.json
index d39f93ea..aa4b57ba 100644
--- a/config.json
+++ b/config.json
@@ -1244,6 +1244,14 @@
           "associative_arrays",
           "control_flow_conditionals"
         ]
+      },
+      {
+        "slug": "save-the-cow",
+        "name": "Save the Cow",
+        "uuid": "21b2a344-925e-427a-a2bb-69122df2ce61",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
       }
     ],
     "foregone": [
diff --git a/exercises/practice/save-the-cow/.docs/instructions.md b/exercises/practice/save-the-cow/.docs/instructions.md
new file mode 100644
index 00000000..1ec98a43
--- /dev/null
+++ b/exercises/practice/save-the-cow/.docs/instructions.md
@@ -0,0 +1,7 @@
+# Instructions
+
+Implement the logic for a word-guessing game.
+
+A player tries to solve a secret word by guessing individual letters.
+They win if they reveal all the letters in the secret word.
+They lose if they make ten incorrect guesses before revealing the word.
diff --git a/exercises/practice/save-the-cow/.docs/introduction.md b/exercises/practice/save-the-cow/.docs/introduction.md
new file mode 100644
index 00000000..c87a7fa9
--- /dev/null
+++ b/exercises/practice/save-the-cow/.docs/introduction.md
@@ -0,0 +1,4 @@
+# Introduction
+
+Bessie the cow has wandered onto an alien spaceship.
+Guess the secret door code to bring her home before the ship blasts off.
diff --git a/exercises/practice/save-the-cow/.meta/config.json b/exercises/practice/save-the-cow/.meta/config.json
new file mode 100644
index 00000000..4d7a536c
--- /dev/null
+++ b/exercises/practice/save-the-cow/.meta/config.json
@@ -0,0 +1,15 @@
+{
+  "authors": [],
+  "files": {
+    "solution": [
+      "save_the_cow.sh"
+    ],
+    "test": [
+      "save_the_cow.bats"
+    ],
+    "example": [
+      ".meta/example.sh"
+    ]
+  },
+  "blurb": "Implement a word-guessing game."
+}
diff --git a/exercises/practice/save-the-cow/.meta/example.sh b/exercises/practice/save-the-cow/.meta/example.sh
new file mode 100644
index 00000000..e69de29b
diff --git a/exercises/practice/save-the-cow/.meta/tests.toml b/exercises/practice/save-the-cow/.meta/tests.toml
new file mode 100644
index 00000000..eca72c42
--- /dev/null
+++ b/exercises/practice/save-the-cow/.meta/tests.toml
@@ -0,0 +1,40 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[71d340f9-fc29-4826-872e-ad7d0b83dd98]
+description = "Initially 9 failures are allowed and no letters are guessed"
+
+[76759c24-8f1a-4fc8-9ffd-d6a1ff0cf03b]
+description = "After 10 failures the game is over"
+
+[d6f2e202-7857-46fb-b709-43a7f3f3b2de]
+description = "Losing with several correct guesses"
+
+[71bc0cda-2032-4637-80c8-fc8771124c08]
+description = "Feeding a correct letter removes underscores"
+
+[5b568a1c-867d-418f-97a8-7b6f8a7ca0a2]
+description = "Feeding a correct letter twice counts as a failure"
+
+[3d40f15b-0271-4c5d-b1a4-3e1f66ff221f]
+description = "Guessing a repeated letter reveals all instances"
+
+[11a86435-e401-4250-a26e-3b0d8c4049ad]
+description = "Getting all the letters right makes for a win"
+
+[b3d81876-84ee-45bb-b531-baa1b05b4709]
+description = "Winning on the last guess is still a win"
+
+[cf204398-5e9f-402f-8bff-42cb7cbbbda9]
+description = "Guessing after a lose is error"
+
+[c2ec5b3d-4923-4a0e-a485-6aa6e78c7ece]
+description = "Guessing after a win is error"
diff --git a/exercises/practice/save-the-cow/save_the_cow.bats b/exercises/practice/save-the-cow/save_the_cow.bats
new file mode 100644
index 00000000..e69de29b
diff --git a/exercises/practice/save-the-cow/save_the_cow.sh b/exercises/practice/save-the-cow/save_the_cow.sh
new file mode 100644
index 00000000..e69de29b

From 803e30c9ca63277238b4ead0bf83fae616b0e3ff Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Sat, 12 Sep 2026 22:43:22 +0200
Subject: [PATCH 2/6] Created `template.j2`, `.bats` file and `example.sh`

---
 .../practice/save-the-cow/.meta/example.sh    |  41 ++
 .../practice/save-the-cow/.meta/template.j2   |  15 +
 .../practice/save-the-cow/bats-extra.bash     | 642 ++++++++++++++++++
 .../practice/save-the-cow/save_the_cow.bats   |  91 +++
 .../practice/save-the-cow/save_the_cow.sh     |  24 +
 5 files changed, 813 insertions(+)
 create mode 100644 exercises/practice/save-the-cow/.meta/template.j2
 create mode 100644 exercises/practice/save-the-cow/bats-extra.bash

diff --git a/exercises/practice/save-the-cow/.meta/example.sh b/exercises/practice/save-the-cow/.meta/example.sh
index e69de29b..e718f49c 100644
--- a/exercises/practice/save-the-cow/.meta/example.sh
+++ b/exercises/practice/save-the-cow/.meta/example.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+guess() {
+    local word="$1"; shift
+    local -a guesses=( "$@" )
+    local state="Ongoing"
+    local remaining_failures=9
+    local masked_word=${word//?/_}
+    local i
+
+    for guess in "${guesses[@]}"; do
+        if [[ $state == "Win" ]]; then
+            echo "cannot guess after the game is won"
+        elif [[ $state == "Lose" ]]; then
+            echo "cannot guess after the game is lost"
+        fi
+
+        if [[ -n $guess && $word =~ $guess && ! $masked_word =~ $guess ]]; then
+            for (( i = 0; i < ${#word}; i++ )); do
+                if [[ ${word:i:1} == "$guess" ]]; then
+                    masked_word="${masked_word:0:i}${guess}${masked_word:i+1}"
+                fi
+            done
+            if [[ ! $masked_word =~ "_" ]]; then
+                state="Win"
+            fi
+        elif [[ -n $guess ]]; then
+            if (( remaining_failures == 0 )); then
+                state="Lose"
+            else
+                (( remaining_failures -- ))
+            fi
+        fi
+    done
+
+    echo "State: $state"
+    echo "Masked word: $masked_word"
+    echo "Remaining failures: $remaining_failures"
+}
+
+guess "$@"
diff --git a/exercises/practice/save-the-cow/.meta/template.j2 b/exercises/practice/save-the-cow/.meta/template.j2
new file mode 100644
index 00000000..f1c7864a
--- /dev/null
+++ b/exercises/practice/save-the-cow/.meta/template.j2
@@ -0,0 +1,15 @@
+{{ header }}
+{% for case in cases %}
+@test "{{ case["descriptions"] | join(": ") }}" {
+    {% if loop.first %}# {% endif %}[[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash {{ solution }} "{{ case["input"]["word"] }}" "{{ case["input"]["guesses"] | join('" "') }}"
+    assert_success
+{%- if case["expect_error"] %}
+    assert_output --partial "{{ case["expect_error_msg"] }}"
+{%- else %}
+    assert_output --partial "{{ case["expected"]["state"] }}"
+    assert_output --partial "{{ case["expected"]["maskedWord"] }}"
+    assert_output --partial "{{ case["expected"]["remainingFailures"] }}"
+{%- endif %}
+}
+{% endfor %}
diff --git a/exercises/practice/save-the-cow/bats-extra.bash b/exercises/practice/save-the-cow/bats-extra.bash
new file mode 100644
index 00000000..7cef63ea
--- /dev/null
+++ b/exercises/practice/save-the-cow/bats-extra.bash
@@ -0,0 +1,642 @@
+# This is the source code for bats-support and bats-assert, concatenated
+# * https://github.com/bats-core/bats-support
+# * https://github.com/bats-core/bats-assert
+#
+# Comments have been removed to save space. See the git repos for full source code.
+
+############################################################
+#
+# bats-support - Supporting library for Bats test helpers
+#
+# Written in 2016 by Zoltan Tombol <zoltan dot tombol at gmail dot com>
+#
+# To the extent possible under law, the author(s) have dedicated all
+# copyright and related and neighboring rights to this software to the
+# public domain worldwide. This software is distributed without any
+# warranty.
+#
+# You should have received a copy of the CC0 Public Domain Dedication
+# along with this software. If not, see
+# <http://creativecommons.org/publicdomain/zero/1.0/>.
+#
+
+# shellcheck disable=SC2120 # (warning): fail references arguments, but none are ever passed.
+fail() {
+  # shellcheck disable=2015 # (info): Note that A && B || C is not if-then-else. C may run when A is true.
+  (( $# == 0 )) && batslib_err || batslib_err "$@"
+  return 1
+}
+
+batslib_is_caller() {
+  local -i is_mode_direct=1
+
+  # Handle options.
+  while (( $# > 0 )); do
+    case "$1" in
+      -i|--indirect) is_mode_direct=0; shift ;;
+      --) shift; break ;;
+      *) break ;;
+    esac
+  done
+
+  # Arguments.
+  local -r func="$1"
+
+  # Check call stack.
+  if (( is_mode_direct )); then
+    [[ $func == "${FUNCNAME[2]}" ]] && return 0
+  else
+    local -i depth
+    for (( depth=2; depth<${#FUNCNAME[@]}; ++depth )); do
+      [[ $func == "${FUNCNAME[$depth]}" ]] && return 0
+    done
+  fi
+
+  return 1
+}
+
+batslib_err() {
+  { if (( $# > 0 )); then
+      echo "$@"
+    else
+      cat -
+    fi
+  } >&2
+}
+
+batslib_count_lines() {
+  local -i n_lines=0
+  local line
+  while IFS='' read -r line || [[ -n $line ]]; do
+    (( ++n_lines ))
+  done < <(printf '%s' "$1")
+  echo "$n_lines"
+}
+
+batslib_is_single_line() {
+  for string in "$@"; do
+    (( $(batslib_count_lines "$string") > 1 )) && return 1
+  done
+  return 0
+}
+
+batslib_get_max_single_line_key_width() {
+  local -i max_len=-1
+  while (( $# != 0 )); do
+    local -i key_len="${#1}"
+    batslib_is_single_line "$2" && (( key_len > max_len )) && max_len="$key_len"
+    shift 2
+  done
+  echo "$max_len"
+}
+
+batslib_print_kv_single() {
+  local -ir col_width="$1"; shift
+  while (( $# != 0 )); do
+    printf '%-*s : %s\n' "$col_width" "$1" "$2"
+    shift 2
+  done
+}
+
+batslib_print_kv_multi() {
+  while (( $# != 0 )); do
+    printf '%s (%d lines):\n' "$1" "$( batslib_count_lines "$2" )"
+    printf '%s\n' "$2"
+    shift 2
+  done
+}
+
+batslib_print_kv_single_or_multi() {
+  local -ir width="$1"; shift
+  local -a pairs=( "$@" )
+
+  local -a values=()
+  local -i i
+  for (( i=1; i < ${#pairs[@]}; i+=2 )); do
+    values+=( "${pairs[$i]}" )
+  done
+
+  if batslib_is_single_line "${values[@]}"; then
+    batslib_print_kv_single "$width" "${pairs[@]}"
+  else
+    local -i i
+    for (( i=1; i < ${#pairs[@]}; i+=2 )); do
+      pairs[i]="$( batslib_prefix < <(printf '%s' "${pairs[$i]}") )"
+    done
+    batslib_print_kv_multi "${pairs[@]}"
+  fi
+}
+
+batslib_prefix() {
+  local -r prefix="${1:-  }"
+  local line
+  while IFS='' read -r line || [[ -n $line ]]; do
+    printf '%s%s\n' "$prefix" "$line"
+  done
+}
+
+batslib_mark() {
+  local -r symbol="$1"; shift
+  # Sort line numbers.
+  # shellcheck disable=SC2046 # (warning): Quote this to prevent word splitting.
+  set -- $( sort -nu <<< "$( printf '%d\n' "$@" )" )
+
+  local line
+  local -i idx=0
+  while IFS='' read -r line || [[ -n $line ]]; do
+    if (( ${1:--1} == idx )); then
+      printf '%s\n' "${symbol}${line:${#symbol}}"
+      shift
+    else
+      printf '%s\n' "$line"
+    fi
+    (( ++idx ))
+  done
+}
+
+batslib_decorate() {
+  echo
+  echo "-- $1 --"
+  cat -
+  echo '--'
+  echo
+}
+
+############################################################
+
+assert() {
+  if ! "$@"; then
+    batslib_print_kv_single 10 'expression' "$*" \
+    | batslib_decorate 'assertion failed' \
+    | fail
+  fi
+}
+
+assert_equal() {
+  if [[ $1 != "$2" ]]; then
+    batslib_print_kv_single_or_multi 8 \
+    'expected' "$2" \
+    'actual'   "$1" \
+    | batslib_decorate 'values do not equal' \
+    | fail
+  fi
+}
+
+assert_failure() {
+  : "${output?}"
+  : "${status?}"
+
+  (( $# > 0 )) && local -r expected="$1"
+  if (( status == 0 )); then
+    batslib_print_kv_single_or_multi 6 'output' "$output" \
+    | batslib_decorate 'command succeeded, but it was expected to fail' \
+    | fail
+  elif (( $# > 0 )) && (( status != expected )); then
+    { local -ir width=8
+      batslib_print_kv_single "$width" \
+      'expected' "$expected" \
+      'actual'   "$status"
+      batslib_print_kv_single_or_multi "$width" \
+      'output' "$output"
+    } \
+    | batslib_decorate 'command failed as expected, but status differs' \
+    | fail
+  fi
+}
+
+assert_line() {
+  local -i is_match_line=0
+  local -i is_mode_partial=0
+  local -i is_mode_regexp=0
+  : "${lines?}"
+
+  # Handle options.
+  while (( $# > 0 )); do
+    case "$1" in
+    -n|--index)
+      if (( $# < 2 )) || ! [[ $2 =~ ^([0-9]|[1-9][0-9]+)$ ]]; then
+        echo "\`--index' requires an integer argument: \`$2'" \
+        | batslib_decorate 'ERROR: assert_line' \
+        | fail
+        return $?
+      fi
+      is_match_line=1
+      local -ri idx="$2"
+      shift 2
+      ;;
+    -p|--partial) is_mode_partial=1; shift ;;
+    -e|--regexp) is_mode_regexp=1; shift ;;
+    --) shift; break ;;
+    *) break ;;
+    esac
+  done
+
+  if (( is_mode_partial )) && (( is_mode_regexp )); then
+    echo "\`--partial' and \`--regexp' are mutually exclusive" \
+    | batslib_decorate 'ERROR: assert_line' \
+    | fail
+    return $?
+  fi
+
+  # Arguments.
+  local -r expected="$1"
+
+  if (( is_mode_regexp == 1 )) && [[ '' =~ $expected ]] || (( $? == 2 )); then
+    echo "Invalid extended regular expression: \`$expected'" \
+    | batslib_decorate 'ERROR: assert_line' \
+    | fail
+    return $?
+  fi
+
+  # Matching.
+  if (( is_match_line )); then
+    # Specific line.
+    if (( is_mode_regexp )); then
+      if ! [[ ${lines[$idx]} =~ $expected ]]; then
+        batslib_print_kv_single 6 \
+        'index' "$idx" \
+        'regexp' "$expected" \
+        'line'  "${lines[$idx]}" \
+        | batslib_decorate 'regular expression does not match line' \
+        | fail
+      fi
+    elif (( is_mode_partial )); then
+      if [[ ${lines[$idx]} != *"$expected"* ]]; then
+        batslib_print_kv_single 9 \
+        'index'     "$idx" \
+        'substring' "$expected" \
+        'line'      "${lines[$idx]}" \
+        | batslib_decorate 'line does not contain substring' \
+        | fail
+      fi
+    else
+      if [[ ${lines[$idx]} != "$expected" ]]; then
+        batslib_print_kv_single 8 \
+        'index'    "$idx" \
+        'expected' "$expected" \
+        'actual'   "${lines[$idx]}" \
+        | batslib_decorate 'line differs' \
+        | fail
+      fi
+    fi
+  else
+    # Contained in output.
+    if (( is_mode_regexp )); then
+      local -i idx
+      for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
+        [[ ${lines[$idx]} =~ $expected ]] && return 0
+      done
+      { local -ar single=( 'regexp' "$expected" )
+        local -ar may_be_multi=( 'output' "$output" )
+        local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
+        batslib_print_kv_single "$width" "${single[@]}"
+        batslib_print_kv_single_or_multi "$width" "${may_be_multi[@]}"
+      } \
+      | batslib_decorate 'no output line matches regular expression' \
+      | fail
+    elif (( is_mode_partial )); then
+      local -i idx
+      for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
+        [[ ${lines[$idx]} == *"$expected"* ]] && return 0
+      done
+      { local -ar single=( 'substring' "$expected" )
+        local -ar may_be_multi=( 'output' "$output" )
+        local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
+        batslib_print_kv_single "$width" "${single[@]}"
+        batslib_print_kv_single_or_multi "$width" "${may_be_multi[@]}"
+      } \
+      | batslib_decorate 'no output line contains substring' \
+      | fail
+    else
+      local -i idx
+      for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
+        [[ ${lines[$idx]} == "$expected" ]] && return 0
+      done
+      { local -ar single=( 'line' "$expected" )
+        local -ar may_be_multi=( 'output' "$output" )
+        local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
+        batslib_print_kv_single "$width" "${single[@]}"
+        batslib_print_kv_single_or_multi "$width" "${may_be_multi[@]}"
+      } \
+      | batslib_decorate 'output does not contain line' \
+      | fail
+    fi
+  fi
+}
+
+assert_output() {
+  local -i is_mode_partial=0
+  local -i is_mode_regexp=0
+  local -i is_mode_nonempty=0
+  local -i use_stdin=0
+  : "${output?}"
+
+  # Handle options.
+  if (( $# == 0 )); then
+    is_mode_nonempty=1
+  fi
+
+  while (( $# > 0 )); do
+    case "$1" in
+    -p|--partial) is_mode_partial=1; shift ;;
+    -e|--regexp) is_mode_regexp=1; shift ;;
+    -|--stdin) use_stdin=1; shift ;;
+    --) shift; break ;;
+    *) break ;;
+    esac
+  done
+
+  if (( is_mode_partial )) && (( is_mode_regexp )); then
+    echo "\`--partial' and \`--regexp' are mutually exclusive" \
+    | batslib_decorate 'ERROR: assert_output' \
+    | fail
+    return $?
+  fi
+
+  # Arguments.
+  local expected
+  if (( use_stdin )); then
+    expected="$(cat -)"
+  else
+    expected="${1-}"
+  fi
+
+  # Matching.
+  if (( is_mode_nonempty )); then
+    if [ -z "$output" ]; then
+      echo 'expected non-empty output, but output was empty' \
+      | batslib_decorate 'no output' \
+      | fail
+    fi
+  elif (( is_mode_regexp )); then
+    # shellcheck disable=SC2319 # (warning) `$?` in a conditional expression: https://github.com/koalaman/shellcheck/wiki/SC2319
+    if [[ '' =~ $expected ]] || (( $? == 2 )); then
+      # the regex matches an empty string or it is syntactically incorrect.
+      echo "Invalid extended regular expression: \`$expected'" \
+      | batslib_decorate 'ERROR: assert_output' \
+      | fail
+    elif ! [[ $output =~ $expected ]]; then
+      batslib_print_kv_single_or_multi 6 \
+      'regexp'  "$expected" \
+      'output' "$output" \
+      | batslib_decorate 'regular expression does not match output' \
+      | fail
+    fi
+  elif (( is_mode_partial )); then
+    if [[ $output != *"$expected"* ]]; then
+      batslib_print_kv_single_or_multi 9 \
+      'substring' "$expected" \
+      'output'    "$output" \
+      | batslib_decorate 'output does not contain substring' \
+      | fail
+    fi
+  else
+    if [[ $output != "$expected" ]]; then
+      batslib_print_kv_single_or_multi 8 \
+      'expected' "$expected" \
+      'actual'   "$output" \
+      | batslib_decorate 'output differs' \
+      | fail
+    fi
+  fi
+}
+
+assert_success() {
+  : "${output?}"
+  : "${status?}"
+
+  if (( status != 0 )); then
+    { local -ir width=6
+      batslib_print_kv_single "$width" 'status' "$status"
+      batslib_print_kv_single_or_multi "$width" 'output' "$output"
+    } \
+    | batslib_decorate 'command failed' \
+    | fail
+  fi
+}
+
+refute() {
+  if "$@"; then
+    batslib_print_kv_single 10 'expression' "$*" \
+    | batslib_decorate 'assertion succeeded, but it was expected to fail' \
+    | fail
+  fi
+}
+
+refute_line() {
+  local -i is_match_line=0
+  local -i is_mode_partial=0
+  local -i is_mode_regexp=0
+  : "${lines?}"
+
+  # Handle options.
+  while (( $# > 0 )); do
+    case "$1" in
+    -n|--index)
+      if (( $# < 2 )) || ! [[ $2 =~ ^([0-9]|[1-9][0-9]+)$ ]]; then
+        echo "\`--index' requires an integer argument: \`$2'" \
+        | batslib_decorate 'ERROR: refute_line' \
+        | fail
+        return $?
+      fi
+      is_match_line=1
+      local -ri idx="$2"
+      shift 2
+      ;;
+    -p|--partial) is_mode_partial=1; shift ;;
+    -e|--regexp) is_mode_regexp=1; shift ;;
+    --) shift; break ;;
+    *) break ;;
+    esac
+  done
+
+  if (( is_mode_partial )) && (( is_mode_regexp )); then
+    echo "\`--partial' and \`--regexp' are mutually exclusive" \
+    | batslib_decorate 'ERROR: refute_line' \
+    | fail
+    return $?
+  fi
+
+  # Arguments.
+  local -r unexpected="$1"
+
+  if (( is_mode_regexp == 1 )) && [[ '' =~ $unexpected ]] || (( $? == 2 )); then
+    echo "Invalid extended regular expression: \`$unexpected'" \
+    | batslib_decorate 'ERROR: refute_line' \
+    | fail
+    return $?
+  fi
+
+  # Matching.
+  if (( is_match_line )); then
+    # Specific line.
+    if (( is_mode_regexp )); then
+      if [[ ${lines[$idx]} =~ $unexpected ]]; then
+        batslib_print_kv_single 6 \
+        'index' "$idx" \
+        'regexp' "$unexpected" \
+        'line'  "${lines[$idx]}" \
+        | batslib_decorate 'regular expression should not match line' \
+        | fail
+      fi
+    elif (( is_mode_partial )); then
+      if [[ ${lines[$idx]} == *"$unexpected"* ]]; then
+        batslib_print_kv_single 9 \
+        'index'     "$idx" \
+        'substring' "$unexpected" \
+        'line'      "${lines[$idx]}" \
+        | batslib_decorate 'line should not contain substring' \
+        | fail
+      fi
+    else
+      if [[ ${lines[$idx]} == "$unexpected" ]]; then
+        batslib_print_kv_single 5 \
+        'index' "$idx" \
+        'line'  "${lines[$idx]}" \
+        | batslib_decorate 'line should differ' \
+        | fail
+      fi
+    fi
+  else
+    # Line contained in output.
+    if (( is_mode_regexp )); then
+      local -i idx
+      for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
+        if [[ ${lines[$idx]} =~ $unexpected ]]; then
+          { local -ar single=( 'regexp' "$unexpected" 'index' "$idx" )
+            local -a may_be_multi=( 'output' "$output" )
+            local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
+            batslib_print_kv_single "$width" "${single[@]}"
+            if batslib_is_single_line "${may_be_multi[1]}"; then
+              batslib_print_kv_single "$width" "${may_be_multi[@]}"
+            else
+              may_be_multi[1]="$( printf '%s' "${may_be_multi[1]}" | batslib_prefix | batslib_mark '>' "$idx" )"
+              batslib_print_kv_multi "${may_be_multi[@]}"
+            fi
+          } \
+          | batslib_decorate 'no line should match the regular expression' \
+          | fail
+          return $?
+        fi
+      done
+    elif (( is_mode_partial )); then
+      local -i idx
+      for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
+        if [[ ${lines[$idx]} == *"$unexpected"* ]]; then
+          { local -ar single=( 'substring' "$unexpected" 'index' "$idx" )
+            local -a may_be_multi=( 'output' "$output" )
+            local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
+            batslib_print_kv_single "$width" "${single[@]}"
+            if batslib_is_single_line "${may_be_multi[1]}"; then
+              batslib_print_kv_single "$width" "${may_be_multi[@]}"
+            else
+              may_be_multi[1]="$( printf '%s' "${may_be_multi[1]}" | batslib_prefix | batslib_mark '>' "$idx" )"
+              batslib_print_kv_multi "${may_be_multi[@]}"
+            fi
+          } \
+          | batslib_decorate 'no line should contain substring' \
+          | fail
+          return $?
+        fi
+      done
+    else
+      local -i idx
+      for (( idx = 0; idx < ${#lines[@]}; ++idx )); do
+        if [[ ${lines[$idx]} == "$unexpected" ]]; then
+          { local -ar single=( 'line' "$unexpected" 'index' "$idx" )
+            local -a may_be_multi=( 'output' "$output" )
+            local -ir width="$( batslib_get_max_single_line_key_width "${single[@]}" "${may_be_multi[@]}" )"
+            batslib_print_kv_single "$width" "${single[@]}"
+            if batslib_is_single_line "${may_be_multi[1]}"; then
+              batslib_print_kv_single "$width" "${may_be_multi[@]}"
+            else
+              may_be_multi[1]="$( printf '%s' "${may_be_multi[1]}" | batslib_prefix | batslib_mark '>' "$idx" )"
+              batslib_print_kv_multi "${may_be_multi[@]}"
+            fi
+          } \
+          | batslib_decorate 'line should not be in output' \
+          | fail
+          return $?
+        fi
+      done
+    fi
+  fi
+}
+
+refute_output() {
+  local -i is_mode_partial=0
+  local -i is_mode_regexp=0
+  local -i is_mode_empty=0
+  local -i use_stdin=0
+  : "${output?}"
+
+  # Handle options.
+  if (( $# == 0 )); then
+    is_mode_empty=1
+  fi
+
+  while (( $# > 0 )); do
+    case "$1" in
+    -p|--partial) is_mode_partial=1; shift ;;
+    -e|--regexp) is_mode_regexp=1; shift ;;
+    -|--stdin) use_stdin=1; shift ;;
+    --) shift; break ;;
+    *) break ;;
+    esac
+  done
+
+  if (( is_mode_partial )) && (( is_mode_regexp )); then
+    echo "\`--partial' and \`--regexp' are mutually exclusive" \
+    | batslib_decorate 'ERROR: refute_output' \
+    | fail
+    return $?
+  fi
+
+  # Arguments.
+  local unexpected
+  if (( use_stdin )); then
+    unexpected="$(cat -)"
+  else
+    unexpected="${1-}"
+  fi
+
+  if (( is_mode_regexp == 1 )) && [[ '' =~ $unexpected ]] || (( $? == 2 )); then
+    echo "Invalid extended regular expression: \`$unexpected'" \
+    | batslib_decorate 'ERROR: refute_output' \
+    | fail
+    return $?
+  fi
+
+  # Matching.
+  if (( is_mode_empty )); then
+    if [ -n "$output" ]; then
+      batslib_print_kv_single_or_multi 6 \
+      'output' "$output" \
+      | batslib_decorate 'output non-empty, but expected no output' \
+      | fail
+    fi
+  elif (( is_mode_regexp )); then
+    if [[ $output =~ $unexpected ]]; then
+      batslib_print_kv_single_or_multi 6 \
+      'regexp'  "$unexpected" \
+      'output' "$output" \
+      | batslib_decorate 'regular expression should not match output' \
+      | fail
+    fi
+  elif (( is_mode_partial )); then
+    if [[ $output == *"$unexpected"* ]]; then
+      batslib_print_kv_single_or_multi 9 \
+      'substring' "$unexpected" \
+      'output'    "$output" \
+      | batslib_decorate 'output should not contain substring' \
+      | fail
+    fi
+  else
+    if [[ $output == "$unexpected" ]]; then
+      batslib_print_kv_single_or_multi 6 \
+      'output' "$output" \
+      | batslib_decorate 'output equals, but it was expected to differ' \
+      | fail
+    fi
+  fi
+}
diff --git a/exercises/practice/save-the-cow/save_the_cow.bats b/exercises/practice/save-the-cow/save_the_cow.bats
index e69de29b..619c169e 100644
--- a/exercises/practice/save-the-cow/save_the_cow.bats
+++ b/exercises/practice/save-the-cow/save_the_cow.bats
@@ -0,0 +1,91 @@
+#!/usr/bin/env bats
+load bats-extra
+
+# generated on 2026-09-12T19:25:52+00:00
+
+@test "Initially 9 failures are allowed and no letters are guessed" {
+    # [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" ""
+    assert_success
+    assert_output --partial "Ongoing"
+    assert_output --partial "____"
+    assert_output --partial "9"
+}
+
+@test "After 10 failures the game is over" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"
+    assert_success
+    assert_output --partial "Lose"
+    assert_output --partial "____"
+    assert_output --partial "0"
+}
+
+@test "Losing with several correct guesses" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "t" "o" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"
+    assert_success
+    assert_output --partial "Lose"
+    assert_output --partial "_oot"
+    assert_output --partial "0"
+}
+
+@test "Feeding a correct letter removes underscores" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "t"
+    assert_success
+    assert_output --partial "Ongoing"
+    assert_output --partial "___t"
+    assert_output --partial "9"
+}
+
+@test "Feeding a correct letter twice counts as a failure" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "t" "t"
+    assert_success
+    assert_output --partial "Ongoing"
+    assert_output --partial "___t"
+    assert_output --partial "8"
+}
+
+@test "Guessing a repeated letter reveals all instances" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "t" "t" "o"
+    assert_success
+    assert_output --partial "Ongoing"
+    assert_output --partial "_oot"
+    assert_output --partial "8"
+}
+
+@test "Getting all the letters right makes for a win" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "t" "t" "o" "l"
+    assert_success
+    assert_output --partial "Win"
+    assert_output --partial "loot"
+    assert_output --partial "8"
+}
+
+@test "Winning on the last guess is still a win" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "a" "b" "c" "d" "e" "f" "g" "h" "i" "t" "o" "l"
+    assert_success
+    assert_output --partial "Win"
+    assert_output --partial "loot"
+    assert_output --partial "0"
+}
+
+@test "Guessing after a lose is error" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k"
+    assert_success
+    assert_output --partial "cannot guess after the game is lost"
+}
+
+@test "Guessing after a win is error" {
+    [[ $BATS_RUN_SKIPPED == "true" ]] || skip
+    run bash save_the_cow.sh "loot" "t" "o" "l" "l"
+    assert_success
+    assert_output --partial "cannot guess after the game is won"
+}
+
diff --git a/exercises/practice/save-the-cow/save_the_cow.sh b/exercises/practice/save-the-cow/save_the_cow.sh
index e69de29b..960869f3 100644
--- a/exercises/practice/save-the-cow/save_the_cow.sh
+++ b/exercises/practice/save-the-cow/save_the_cow.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+# The following comments should help you get started:
+# - Bash is flexible. You may use functions or write a "raw" script.
+#
+# - Complex code can be made easier to read by breaking it up
+#   into functions, however this is sometimes overkill in bash.
+#
+# - You can find links about good style and other resources
+#   for Bash in './README.md'. It came with this exercise.
+#
+#   Example:
+#   # other functions here
+#   # ...
+#   # ...
+#
+#   main () {
+#     # your main function code here
+#   }
+#
+#   # call main with all of the positional arguments
+#   main "$@"
+#
+# *** PLEASE REMOVE THESE COMMENTS BEFORE SUBMITTING YOUR SOLUTION ***

From 810c0f7058855dc50a9d24036480b9dd16e43b85 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Sat, 12 Sep 2026 22:46:15 +0200
Subject: [PATCH 3/6] Set the difficulty rank to `3`

---
 config.json | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/config.json b/config.json
index aa4b57ba..d526a31d 100644
--- a/config.json
+++ b/config.json
@@ -556,6 +556,14 @@
           "string_transformation"
         ]
       },
+      {
+        "slug": "save-the-cow",
+        "name": "Save the Cow",
+        "uuid": "21b2a344-925e-427a-a2bb-69122df2ce61",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
+      },
       {
         "slug": "sieve",
         "name": "Sieve",
@@ -1244,14 +1252,6 @@
           "associative_arrays",
           "control_flow_conditionals"
         ]
-      },
-      {
-        "slug": "save-the-cow",
-        "name": "Save the Cow",
-        "uuid": "21b2a344-925e-427a-a2bb-69122df2ce61",
-        "practices": [],
-        "prerequisites": [],
-        "difficulty": 1
       }
     ],
     "foregone": [

From bf95978253df65b1d34d55113b0f02755fccbdd9 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Sat, 12 Sep 2026 22:49:09 +0200
Subject: [PATCH 4/6] Added GitHub handle to `config.json`

---
 exercises/practice/save-the-cow/.meta/config.json | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/exercises/practice/save-the-cow/.meta/config.json b/exercises/practice/save-the-cow/.meta/config.json
index 4d7a536c..0a529ef9 100644
--- a/exercises/practice/save-the-cow/.meta/config.json
+++ b/exercises/practice/save-the-cow/.meta/config.json
@@ -1,5 +1,7 @@
 {
-  "authors": [],
+  "authors": [
+    "resu-xuniL"
+  ],
   "files": {
     "solution": [
       "save_the_cow.sh"

From 145bf571270981a2a0cd7036fbbe78be0f0264c2 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Sun, 13 Sep 2026 20:07:34 +0200
Subject: [PATCH 5/6] Change error tests with `assert_failure`

---
 exercises/practice/save-the-cow/.meta/example.sh  |  6 ++++--
 exercises/practice/save-the-cow/.meta/template.j2 |  5 +++--
 exercises/practice/save-the-cow/save_the_cow.bats | 10 +++++-----
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/exercises/practice/save-the-cow/.meta/example.sh b/exercises/practice/save-the-cow/.meta/example.sh
index e718f49c..74cea1a6 100644
--- a/exercises/practice/save-the-cow/.meta/example.sh
+++ b/exercises/practice/save-the-cow/.meta/example.sh
@@ -10,9 +10,11 @@ guess() {
 
     for guess in "${guesses[@]}"; do
         if [[ $state == "Win" ]]; then
-            echo "cannot guess after the game is won"
+            echo "cannot guess after the game is won" >&2
+            exit 1
         elif [[ $state == "Lose" ]]; then
-            echo "cannot guess after the game is lost"
+            echo "cannot guess after the game is lost" >&2
+            exit 1
         fi
 
         if [[ -n $guess && $word =~ $guess && ! $masked_word =~ $guess ]]; then
diff --git a/exercises/practice/save-the-cow/.meta/template.j2 b/exercises/practice/save-the-cow/.meta/template.j2
index f1c7864a..75d64b3b 100644
--- a/exercises/practice/save-the-cow/.meta/template.j2
+++ b/exercises/practice/save-the-cow/.meta/template.j2
@@ -3,10 +3,11 @@
 @test "{{ case["descriptions"] | join(": ") }}" {
     {% if loop.first %}# {% endif %}[[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash {{ solution }} "{{ case["input"]["word"] }}" "{{ case["input"]["guesses"] | join('" "') }}"
-    assert_success
 {%- if case["expect_error"] %}
-    assert_output --partial "{{ case["expect_error_msg"] }}"
+    assert_failure
+    assert_output "{{ case["expect_error_msg"] }}"
 {%- else %}
+    assert_success
     assert_output --partial "{{ case["expected"]["state"] }}"
     assert_output --partial "{{ case["expected"]["maskedWord"] }}"
     assert_output --partial "{{ case["expected"]["remainingFailures"] }}"
diff --git a/exercises/practice/save-the-cow/save_the_cow.bats b/exercises/practice/save-the-cow/save_the_cow.bats
index 619c169e..583ca715 100644
--- a/exercises/practice/save-the-cow/save_the_cow.bats
+++ b/exercises/practice/save-the-cow/save_the_cow.bats
@@ -1,7 +1,7 @@
 #!/usr/bin/env bats
 load bats-extra
 
-# generated on 2026-09-12T19:25:52+00:00
+# generated on 2026-09-13T17:59:07+00:00
 
 @test "Initially 9 failures are allowed and no letters are guessed" {
     # [[ $BATS_RUN_SKIPPED == "true" ]] || skip
@@ -78,14 +78,14 @@ load bats-extra
 @test "Guessing after a lose is error" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k"
-    assert_success
-    assert_output --partial "cannot guess after the game is lost"
+    assert_failure
+    assert_output "cannot guess after the game is lost"
 }
 
 @test "Guessing after a win is error" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "t" "o" "l" "l"
-    assert_success
-    assert_output --partial "cannot guess after the game is won"
+    assert_failure
+    assert_output "cannot guess after the game is won"
 }
 

From cbcec9afe03cc22a63d4aac0b8f504284efe8b53 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Sun, 13 Sep 2026 21:25:13 +0200
Subject: [PATCH 6/6] Change for more concrete expectations

---
 .../practice/save-the-cow/.meta/example.sh    |  4 +-
 .../practice/save-the-cow/.meta/template.j2   | 11 ++-
 .../practice/save-the-cow/save_the_cow.bats   | 90 +++++++++++++------
 3 files changed, 74 insertions(+), 31 deletions(-)

diff --git a/exercises/practice/save-the-cow/.meta/example.sh b/exercises/practice/save-the-cow/.meta/example.sh
index 74cea1a6..b4b1929d 100644
--- a/exercises/practice/save-the-cow/.meta/example.sh
+++ b/exercises/practice/save-the-cow/.meta/example.sh
@@ -35,9 +35,7 @@ guess() {
         fi
     done
 
-    echo "State: $state"
-    echo "Masked word: $masked_word"
-    echo "Remaining failures: $remaining_failures"
+    printf "State: %s\nMasked word: %s\nRemaining failures: %s" "$state" "$masked_word" "$remaining_failures"
 }
 
 guess "$@"
diff --git a/exercises/practice/save-the-cow/.meta/template.j2 b/exercises/practice/save-the-cow/.meta/template.j2
index 75d64b3b..a95eca34 100644
--- a/exercises/practice/save-the-cow/.meta/template.j2
+++ b/exercises/practice/save-the-cow/.meta/template.j2
@@ -7,10 +7,15 @@
     assert_failure
     assert_output "{{ case["expect_error_msg"] }}"
 {%- else %}
+    expected="$(cat << EXPECTED
+State: {{ case["expected"]["state"] }}
+Masked word: {{ case["expected"]["maskedWord"] }}
+Remaining failures: {{ case["expected"]["remainingFailures"] }}
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "{{ case["expected"]["state"] }}"
-    assert_output --partial "{{ case["expected"]["maskedWord"] }}"
-    assert_output --partial "{{ case["expected"]["remainingFailures"] }}"
+    assert_output "$expected"
 {%- endif %}
 }
 {% endfor %}
diff --git a/exercises/practice/save-the-cow/save_the_cow.bats b/exercises/practice/save-the-cow/save_the_cow.bats
index 583ca715..e3ff5375 100644
--- a/exercises/practice/save-the-cow/save_the_cow.bats
+++ b/exercises/practice/save-the-cow/save_the_cow.bats
@@ -1,78 +1,118 @@
 #!/usr/bin/env bats
 load bats-extra
 
-# generated on 2026-09-13T17:59:07+00:00
+# generated on 2026-09-13T19:12:55+00:00
 
 @test "Initially 9 failures are allowed and no letters are guessed" {
     # [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" ""
+    expected="$(cat << EXPECTED
+State: Ongoing
+Masked word: ____
+Remaining failures: 9
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Ongoing"
-    assert_output --partial "____"
-    assert_output --partial "9"
+    assert_output "$expected"
 }
 
 @test "After 10 failures the game is over" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"
+    expected="$(cat << EXPECTED
+State: Lose
+Masked word: ____
+Remaining failures: 0
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Lose"
-    assert_output --partial "____"
-    assert_output --partial "0"
+    assert_output "$expected"
 }
 
 @test "Losing with several correct guesses" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "t" "o" "a" "b" "c" "d" "e" "f" "g" "h" "i" "j"
+    expected="$(cat << EXPECTED
+State: Lose
+Masked word: _oot
+Remaining failures: 0
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Lose"
-    assert_output --partial "_oot"
-    assert_output --partial "0"
+    assert_output "$expected"
 }
 
 @test "Feeding a correct letter removes underscores" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "t"
+    expected="$(cat << EXPECTED
+State: Ongoing
+Masked word: ___t
+Remaining failures: 9
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Ongoing"
-    assert_output --partial "___t"
-    assert_output --partial "9"
+    assert_output "$expected"
 }
 
 @test "Feeding a correct letter twice counts as a failure" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "t" "t"
+    expected="$(cat << EXPECTED
+State: Ongoing
+Masked word: ___t
+Remaining failures: 8
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Ongoing"
-    assert_output --partial "___t"
-    assert_output --partial "8"
+    assert_output "$expected"
 }
 
 @test "Guessing a repeated letter reveals all instances" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "t" "t" "o"
+    expected="$(cat << EXPECTED
+State: Ongoing
+Masked word: _oot
+Remaining failures: 8
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Ongoing"
-    assert_output --partial "_oot"
-    assert_output --partial "8"
+    assert_output "$expected"
 }
 
 @test "Getting all the letters right makes for a win" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "t" "t" "o" "l"
+    expected="$(cat << EXPECTED
+State: Win
+Masked word: loot
+Remaining failures: 8
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Win"
-    assert_output --partial "loot"
-    assert_output --partial "8"
+    assert_output "$expected"
 }
 
 @test "Winning on the last guess is still a win" {
     [[ $BATS_RUN_SKIPPED == "true" ]] || skip
     run bash save_the_cow.sh "loot" "a" "b" "c" "d" "e" "f" "g" "h" "i" "t" "o" "l"
+    expected="$(cat << EXPECTED
+State: Win
+Masked word: loot
+Remaining failures: 0
+EXPECTED
+    )"
+
     assert_success
-    assert_output --partial "Win"
-    assert_output --partial "loot"
-    assert_output --partial "0"
+    assert_output "$expected"
 }
 
 @test "Guessing after a lose is error" {