---
name: "log4tango::Logger"
section: "3"
platform: "linux"
package: "liblog4tango-doc"
version: "9.3.4+dfsg1-2+deb12u1"
release: "Debian 12 (Bookworm)"
platforms: ["linux"]
url: "https://new.carta.tech/log4tango::Logger"
---

# log4tango::Logger(3)

## NAME

log4tango::Logger

## SYNOPSIS

`#include <Logger.hh>`

Inherits **log4tango::AppenderAttachable**.

### Public Member Functions

**Logger** (const std::string &name, **Level::Value** level=**Level::OFF**)\
 Constructor.  virtual **~Logger** ()\
 Destructor.  const std::string & **get\_name** () const\
 Return the logger name.  void **set\_level** (**Level::Value** level)\
 Set the level of this **Logger** (silently ignores invalid values)  **Level::Value** **get\_level** () const\
 Returns the assigned **Level**, if any, for this **Logger**.  bool **is\_level\_enabled** (**Level::Value** level) const\
 Returns true if the level of the **Logger** is equal to or higher than given level.  void **log** (**Level::Value** level, const char \*string\_format,...)\
 Log a message with the specified level.  void **log** (**Level::Value** level, const std::string &message)\
 Log a message with the specified level.  void **log\_unconditionally** (**Level::Value** level, const char \*string\_format,...)\
 Log a message with the specified level without level checking.  void **log\_unconditionally** (**Level::Value** level, const std::string &message)\
 Log a message with the specified level without level checking.  void **debug** (const char \*string\_format,...)\
 Log a message with debug level.  void **debug** (const std::string &message)\
 Log a message with debug level.  bool **is\_debug\_enabled** (void) const\
 Return true if the **Logger** will log messages with level DEBUG.  **LoggerStream** **debug\_stream** (void)\
 Return a **LoggerStream** with level DEBUG.  void **info** (const char \*string\_format,...)\
 Log a message with info level.  void **info** (const std::string &message)\
 Log a message with info level.  bool **is\_info\_enabled** (void) const\
 Return true if the **Logger** will log messages with level INFO.  **LoggerStream** **info\_stream** (void)\
 Return a **LoggerStream** with level INFO.  void **warn** (const char \*string\_format,...)\
 Log a message with warn level.  void **warn** (const std::string &message)\
 Log a message with warn level.  bool **is\_warn\_enabled** (void) const\
 Return true if the **Logger** will log messages with level WARN.  **LoggerStream** **warn\_stream** (void)\
 Return a **LoggerStream** with level WARN.  void **error** (const char \*string\_format,...)\
 Log a message with error level.  void **error** (const std::string &message)\
 Log a message with error level.  bool **is\_error\_enabled** (void) const\
 Return true if the **Logger** will log messages with level ERROR.  **LoggerStream** **error\_stream** (void)\
 Return a **LoggerStream** with level ERROR.  void **fatal** (const char \*string\_format,...)\
 Log a message with fatal level.  void **fatal** (const std::string &message)\
 Log a message with fatal level.  bool **is\_fatal\_enabled** (void) const\
 Return true if the **Logger** will log messages with level FATAL.  **LoggerStream** **fatal\_stream** (void)\
 Return a **LoggerStream** with level FATAL.  **LoggerStream** **get\_stream** (**Level::Value** level, bool filter=true)\
 Return a **LoggerStream** with given **Level**.

### Protected Member Functions

void **call\_appenders** (const **LoggingEvent** &event)\
 Call the appenders.

### Additional Inherited Members

## Constructor & Destructor Documentation

### log4tango::Logger::Logger (const std::string & name, Level::Value level = Level::OFF)

Constructor.

**Parameters**

*name* the fully qualified name of this **Logger** \
 *level* the level for this **Logger**. Defaults to **Level::OFF**

### log4tango::Logger::~Logger ()` [virtual]`

Destructor.

## Member Function Documentation

### void log4tango::Logger::call\_appenders (const LoggingEvent & event)` [protected]`

Call the appenders.

**Parameters**

*event* the LogginEvent to log.

### void log4tango::Logger::debug (const char \* string\_format, ...)

Log a message with debug level.

**Parameters**

*string\_format* Format specifier for the log. \
 *...* The arguments for string\_format

### void log4tango::Logger::debug (const std::string & message)` [inline]`

Log a message with debug level.

**Parameters**

*message* string to write in the log file

### LoggerStream log4tango::Logger::debug\_stream (void)` [inline]`

Return a **LoggerStream** with level DEBUG.

**Returns**

The **LoggerStream**.

### void log4tango::Logger::error (const char \* string\_format, ...)

Log a message with error level.

**Parameters**

*string\_format* Format specifier for the log. \
 *...* The arguments for string\_format

### void log4tango::Logger::error (const std::string & message)` [inline]`

Log a message with error level.

**Parameters**

*message* string to write in the log file

### LoggerStream log4tango::Logger::error\_stream (void)` [inline]`

Return a **LoggerStream** with level ERROR.

**Returns**

The **LoggerStream**.

### void log4tango::Logger::fatal (const char \* string\_format, ...)

Log a message with fatal level.

**Parameters**

*string\_format* Format specifier for the log. \
 *...* The arguments for string\_format

### void log4tango::Logger::fatal (const std::string & message)` [inline]`

Log a message with fatal level.

**Parameters**

*message* string to write in the log file

### LoggerStream log4tango::Logger::fatal\_stream (void)` [inline]`

Return a **LoggerStream** with level FATAL.

**Returns**

The **LoggerStream**.

### Level::Value log4tango::Logger::get\_level () const` [inline]`

Returns the assigned **Level**, if any, for this **Logger**.

**Returns**

**Level** - the assigned **Level**, can be Level::NOTSET

### const std::string & log4tango::Logger::get\_name () const` [inline]`

Return the logger name.

**Returns**

The logger name.

### LoggerStream log4tango::Logger::get\_stream (Level::Value level, bool filter = `true`)` [inline]`

Return a **LoggerStream** with given **Level**.

**Parameters**

*level* The **Level** of the **LoggerStream**. \
 *filter* The filter flag

**Returns**

The requested **LoggerStream**.

### void log4tango::Logger::info (const char \* string\_format, ...)

Log a message with info level.

**Parameters**

*string\_format* Format specifier for the log. \
 *...* The arguments for string\_format

### void log4tango::Logger::info (const std::string & message)` [inline]`

Log a message with info level.

**Parameters**

*message* string to write in the log file

### LoggerStream log4tango::Logger::info\_stream (void)` [inline]`

Return a **LoggerStream** with level INFO.

**Returns**

The **LoggerStream**.

### bool log4tango::Logger::is\_debug\_enabled (void) const` [inline]`

Return true if the **Logger** will log messages with level DEBUG.

**Returns**

Whether the **Logger** will log.

### bool log4tango::Logger::is\_error\_enabled (void) const` [inline]`

Return true if the **Logger** will log messages with level ERROR.

**Returns**

Whether the **Logger** will log.

### bool log4tango::Logger::is\_fatal\_enabled (void) const` [inline]`

Return true if the **Logger** will log messages with level FATAL.

**Returns**

Whether the **Logger** will log.

### bool log4tango::Logger::is\_info\_enabled (void) const` [inline]`

Return true if the **Logger** will log messages with level INFO.

**Returns**

Whether the **Logger** will log.

### bool log4tango::Logger::is\_level\_enabled (Level::Value level) const` [inline]`

Returns true if the level of the **Logger** is equal to or higher than given level.

**Parameters**

*level* The level to compare with.

**Returns**

whether logging is enable for this level.

### bool log4tango::Logger::is\_warn\_enabled (void) const` [inline]`

Return true if the **Logger** will log messages with level WARN.

**Returns**

Whether the **Logger** will log.

### void log4tango::Logger::log (Level::Value level, const char \* string\_format, ...)

Log a message with the specified level.

**Parameters**

*level* The level of this log message. \
 *string\_format* Format specifier for the log . \
 *...* The arguments for string\_format

### void log4tango::Logger::log (Level::Value level, const std::string & message)` [inline]`

Log a message with the specified level.

**Parameters**

*level* The level of this log message. \
 *message* string to write in the log file

### void log4tango::Logger::log\_unconditionally (Level::Value level, const char \* string\_format, ...)

Log a message with the specified level without level checking.

**Parameters**

*level* The level of this log message. \
 *string\_format* Format specifier for the log . \
 *...* The arguments for string\_format

### void log4tango::Logger::log\_unconditionally (Level::Value level, const std::string & message)

Log a message with the specified level without level checking.

**Parameters**

*level* The level of this log message. \
 *message* string to write in the log file

### void log4tango::Logger::set\_level (Level::Value level)

Set the level of this **Logger** (silently ignores invalid values)

**Parameters**

*level* The level to set.

### void log4tango::Logger::warn (const char \* string\_format, ...)

Log a message with warn level.

**Parameters**

*string\_format* Format specifier for the log. \
 *...* The arguments for string\_format

### void log4tango::Logger::warn (const std::string & message)` [inline]`

Log a message with warn level.

**Parameters**

*message* string to write in the log file

### LoggerStream log4tango::Logger::warn\_stream (void)` [inline]`

Return a **LoggerStream** with level WARN.

**Returns**

The **LoggerStream**.

## Author

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