feat: add init_message option to suppress initialization log entry

configuration/logging.conf.example

@@ -69,6 +69,12 @@ stderr_level = ERROR
 # Set to true to suppress all console output (useful for daemon scripts)
 quiet = false
 
+# Write the INIT message to the log file on initialization (default: true)
+# Set to false to suppress "Logger initialized by <name>" from being appended to the
+# log file on every init_logger call (useful when multiple scripts share the same log
+# file, e.g. a main script and subscripts that all log to the same file)
+init_message = true
+
 # Enable verbose/debug logging (default: false)
 # When true, sets log level to DEBUG
 # Note: If both 'verbose' and 'level' are set, 'level' takes precedence

demo-scripts/demo_config.sh

@@ -108,6 +108,46 @@ log_error "Error message in JSON format"
 # Clean up temporary config file
 rm -f "$CONFIG_FILE"
 
+echo -e "\n========== Testing init_message suppression =========="
+echo "When multiple scripts share a log file (e.g. a main script and subscripts)"
+echo "repeated INIT entries can clutter the log. Use --no-init-message to suppress them."
+echo
+
+SHARED_LOG="${LOGS_DIR}/demo_config_shared.log"
+true > "$SHARED_LOG"
+
+echo "--- Run 1: default behaviour (INIT message written) ---"
+init_logger --log "$SHARED_LOG" || {
+    echo "Failed to initialize logger" >&2
+    exit 1
+}
+log_info "Message from main script"
+
+echo "--- Run 2: subscript using --no-init-message (no extra INIT entry) ---"
+init_logger --log "$SHARED_LOG" --no-init-message || {
+    echo "Failed to initialize logger" >&2
+    exit 1
+}
+log_info "Message from subscript"
+
+echo "--- Run 3: same suppression via config file ---"
+cat > "$CONFIG_FILE" << 'EOF'
+[logging]
+init_message = false
+EOF
+init_logger --config "$CONFIG_FILE" --log "$SHARED_LOG" || {
+    echo "Failed to initialize logger" >&2
+    exit 1
+}
+log_info "Message from another subscript (config-driven)"
+
+echo
+echo "Shared log file contents (note: only one INIT entry from run 1):"
+cat "$SHARED_LOG"
+
+# Clean up
+rm -f "$CONFIG_FILE" "$SHARED_LOG"
+
 echo -e "\n========== Configuration File Demo Complete =========="
 echo "Log file: ${LOGGING_FILE}"
 echo

docs/configuration.md

@@ -8,6 +8,8 @@ configuration from code.
 
 * [Configuration File Format](#configuration-file-format)
 * [Configuration Keys](#configuration-keys)
+  * [Syslog Facility Key](#syslog-facility-key)
+  * [Configuration Value Limits](#configuration-value-limits)
   * [Boolean Values](#boolean-values)
   * [Key Aliases](#key-aliases)
 * [Using Configuration Files](#using-configuration-files)
@@ -120,6 +122,7 @@ max_journal_length = 4096
 | `unsafe_allow_ansi_codes` | `unsafe-allow-ansi-codes`                   | true/false, yes/no, on/off, 1/0                                   | `false`           | Allow ANSI codes in log messages (unsafe) |
 | `max_line_length`         | `max-line-length`, `log_max_line_length`    | Non-negative integer (0 = unlimited)                              | `4096`            | Max message length before formatting      |
 | `max_journal_length`      | `max-journal-length`, `journal_max_length`  | Non-negative integer (0 = unlimited)                              | `4096`            | Max message length for journal            |
+| `init_message`            | `log_init_message`                          | true/false, yes/no, on/off, 1/0                                   | `true`            | Write INIT entry to log file on startup   |
 
 ### Syslog Facility Key
 

docs/initialization.md

@@ -71,6 +71,7 @@ The `init_logger` function accepts the following options:
 | `-F, --facility FACILITY`                       | Set syslog facility for journal logs (default: daemon)                              |
 | `--color, --colour`                             | Explicitly enable color output (default: auto-detect)                               |
 | `--no-color, --no-colour`                       | Disable color output                                                                |
+| `--no-init-message`                             | Suppress the INIT entry written to the log file on initialization                   |
 | `-U, --unsafe-allow-newlines`                   | Allow newlines in log messages (not recommended; disables sanitization)             |
 | `-A, --unsafe-allow-ansi-codes`                 | Allow ANSI escape codes in log messages (not recommended; disables sanitization)    |
 | `--max-line-length LENGTH`                      | Max message length before formatting for console/file output (0 = unlimited)        |

logging.sh

@@ -87,6 +87,7 @@ LOG_FILE=""
 VERBOSE="false"
 CURRENT_LOG_LEVEL=$LOG_LEVEL_INFO
 USE_UTC="false" # Set to true to use UTC time in logs
+LOG_INIT_MESSAGE="true" # Set to false to suppress the INIT message written to the log file on init_logger
 
 # Journal logging settings
 USE_JOURNAL="false"
@@ -703,11 +704,25 @@ _parse_config_file() {
                         echo "  Hint: Using default value of 4096" >&2
                     fi
                     ;;
+                init_message|log_init_message)
+                    case "${value,,}" in
+                        true|yes|1|on)
+                            LOG_INIT_MESSAGE="true"
+                            ;;
+                        false|no|0|off)
+                            LOG_INIT_MESSAGE="false"
+                            ;;
+                        *)
+                            echo "Warning: Invalid init_message value '$value' at line $line_num, expected true/false" >&2
+                            ;;
+                    esac
+                    ;;
                 *)
                     echo "Warning: Unknown configuration key '$key' at line $line_num" >&2
                     echo "  Hint: Valid keys are: level, format, log_file, journal, tag, utc, color," >&2
                     echo "        stderr_level, quiet, console_log, script_name, verbose," >&2
-                    echo "        unsafe_allow_newlines, unsafe_allow_ansi_codes, max_line_length, max_journal_length" >&2
+                    echo "        unsafe_allow_newlines, unsafe_allow_ansi_codes, max_line_length, max_journal_length," >&2
+                    echo "        init_message" >&2
                     ;;
             esac
         else
@@ -1210,6 +1225,10 @@ init_logger() {
                 fi
                 shift 2
                 ;;
+            --no-init-message)
+                LOG_INIT_MESSAGE="false"
+                shift
+                ;;
             *)
                 echo "Unknown parameter for logger: $1" >&2
                 return 1
@@ -1288,13 +1307,16 @@ init_logger() {
         fi
 
         # Write the initialization message using the same format
-        local init_message
-        init_message=$(_format_log_message "INIT" "Logger initialized by $SCRIPT_NAME")
-        echo "$init_message" >> "$LOG_FILE" 2>/dev/null || {
-            echo "Error: Failed to write test message to log file" >&2
-            echo "  Hint: Verify the file is writable and disk space is available" >&2
-            return 1
-        }
+        # Can be suppressed with --no-init-message (or init_message=false in config)
+        if [[ "$LOG_INIT_MESSAGE" == "true" ]]; then
+            local init_message
+            init_message=$(_format_log_message "INIT" "Logger initialized by $SCRIPT_NAME")
+            echo "$init_message" >> "$LOG_FILE" 2>/dev/null || {
+                echo "Error: Failed to write initialization message to log file" >&2
+                echo "  Hint: Verify the file is writable and disk space is available" >&2
+                return 1
+            }
+        fi
 
         echo "Logger: Successfully initialized with log file enabled" >&2
     fi

tests/test_initialization.sh

@@ -384,6 +384,54 @@ EOF
     pass_test
 }
 
+# Test: INIT message written to log file by default
+test_init_message_default() {
+    start_test "INIT message is written to log file by default"
+
+    local log_file="$TEST_DIR/init_default.log"
+    init_logger --log "$log_file"
+
+    assert_file_contains "$log_file" "INIT" || return
+    assert_file_contains "$log_file" "Logger initialized" || return
+    assert_equals "true" "$LOG_INIT_MESSAGE" || return
+
+    pass_test
+}
+
+# Test: --no-init-message suppresses the INIT log file entry
+test_no_init_message_flag() {
+    start_test "--no-init-message suppresses INIT entry in log file"
+
+    local log_file="$TEST_DIR/no_init_flag.log"
+    init_logger --log "$log_file" --no-init-message
+
+    assert_file_not_contains "$log_file" "Logger initialized" || return
+    assert_file_not_contains "$log_file" " INIT " || return
+    assert_equals "false" "$LOG_INIT_MESSAGE" || return
+
+    pass_test
+}
+
+# Test: init_message = false in config suppresses the INIT log file entry
+test_no_init_message_config() {
+    start_test "init_message=false in config suppresses INIT entry in log file"
+
+    local config_file="$TEST_DIR/no_init.conf"
+    cat > "$config_file" << 'EOF'
+[logging]
+init_message = false
+EOF
+
+    local log_file="$TEST_DIR/no_init_config.log"
+    init_logger --config "$config_file" --log "$log_file"
+
+    assert_file_not_contains "$log_file" "Logger initialized" || return
+    assert_file_not_contains "$log_file" " INIT " || return
+    assert_equals "false" "$LOG_INIT_MESSAGE" || return
+
+    pass_test
+}
+
 # Run all tests
 test_default_initialization
 test_quiet_option
@@ -413,3 +461,6 @@ test_script_name_short_option
 test_script_name_in_output
 test_script_name_from_config
 test_script_name_cli_overrides_config
+test_init_message_default
+test_no_init_message_flag
+test_no_init_message_config