Log Unicode C Reference Documentation

Log

Current Version: 11.5.0

Chilkat.Log

Build readable structured diagnostic logs with nested context and tagged values.

Chilkat.Log is a lightweight structured logging helper for creating readable diagnostic logs from application code. It can record nested operation contexts, informational messages, error messages, timestamps, integers, 64-bit integers, tagged values, binary data, Base64 data, hex data, shortened data previews, and computed hashes. It is useful when code needs a clear step-by-step record of operations, inputs, outputs, and diagnostic values for troubleshooting.

Nested operation context

Use EnterContext and LeaveContext to group log entries under readable operation names.

Messages and errors

Add informational messages, error messages, and tagged text values to explain what the application is doing.

Numbers and timestamps

Log integers, 64-bit integers, timestamps, and date/time values when tracing state changes or timing-sensitive workflows.

Binary diagnostics

Record binary data as Base64, hex, or shortened previews so byte-level values can be inspected safely in text logs.

Hash logging

Compute and log hashes of data when comparing content, verifying transformations, or avoiding full data dumps.

Clear and reuse

Clear the log and continue building new diagnostic output during repeated operations or test runs.

Common pattern: Create a Log object, enter a named context for the operation, log the important values and decisions as the code runs, leave the context, and inspect the resulting text if troubleshooting is needed. Use Chilkat.Log for application-level diagnostic output; use LastErrorText on Chilkat objects for detailed diagnostics from Chilkat method calls.

Create/Dispose

HCkLogW instance = CkLogW_Create();
// ...
CkLogW_Dispose(instance);
HCkLogW CkLogW_Create(void);

Creates an instance of the HCkLogW object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.

void CkLogW_Dispose(HCkLogW handle);

Objects created by calling CkLogW_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkLogW_Dispose.

Properties

DebugLogFilePath
void CkLogW_getDebugLogFilePath(HCkLogW cHandle, HCkString retval);
void CkLogW_putDebugLogFilePath(HCkLogW cHandle, const wchar_t *newVal);
const wchar_t *CkLogW_debugLogFilePath(HCkLogW cHandle);

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

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LastErrorHtml
void CkLogW_getLastErrorHtml(HCkLogW cHandle, HCkString retval);
const wchar_t *CkLogW_lastErrorHtml(HCkLogW cHandle);

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
void CkLogW_getLastErrorText(HCkLogW cHandle, HCkString retval);
const wchar_t *CkLogW_lastErrorText(HCkLogW cHandle);

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
void CkLogW_getLastErrorXml(HCkLogW cHandle, HCkString retval);
const wchar_t *CkLogW_lastErrorXml(HCkLogW cHandle);

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
BOOL CkLogW_getLastMethodSuccess(HCkLogW cHandle);
void CkLogW_putLastMethodSuccess(HCkLogW cHandle, BOOL newVal);

Indicates the success or failure of the most recent method call: TRUE means success, FALSE means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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VerboseLogging
BOOL CkLogW_getVerboseLogging(HCkLogW cHandle);
void CkLogW_putVerboseLogging(HCkLogW cHandle, BOOL newVal);

If set to TRUE, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is FALSE. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
void CkLogW_getVersion(HCkLogW cHandle, HCkString retval);
const wchar_t *CkLogW_version(HCkLogW cHandle);

Version of the component/library, such as "10.1.0"

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Methods

Clear
void CkLogW_Clear(HCkLogW cHandle, const wchar_t *initialTag);
Introduced in version 9.5.0.44

Clears all existing log entries and starts a new log whose top-level context is named initialTag.

Typical use: Call this at the beginning of an operation or test run, then add entries with the other Log* methods. The completed structured log can be inspected through the Log object's diagnostic text, such as LastErrorText.
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EnterContext
void CkLogW_EnterContext(HCkLogW cHandle, const wchar_t *tag);
Introduced in version 9.5.0.44

Begins a nested logging context named tag. Entries written after this call are grouped inside the new context until a matching LeaveContext is called.

Balanced contexts: Pair each EnterContext with LeaveContext. Contexts may be nested to reflect operation hierarchy.
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LeaveContext
void CkLogW_LeaveContext(HCkLogW cHandle);
Introduced in version 9.5.0.44

Ends the current nested logging context and returns logging to its parent context.

Empty contexts are omitted: If nothing was logged after entering the current context, Chilkat automatically removes that empty context when it is left.
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LogData
void CkLogW_LogData(HCkLogW cHandle, const wchar_t *tag, const wchar_t *message);
Introduced in version 9.5.0.44

Adds a tagged text value to the current context. The output associates tag with message, making this useful for named values such as filenames, paths, IDs, states, or protocol fields.

Sensitive data: Avoid logging passwords, private keys, access tokens, session secrets, or other sensitive values unless disclosure is intentional.
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LogDataBase64_2
void CkLogW_LogDataBase64_2(HCkLogW cHandle, const wchar_t *tag, const void * pByteData, unsigned long szByteData);
Introduced in version 9.5.0.82

Encodes szByteData bytes beginning at pByteData as Base64 and logs the result under tag.

C++ byte buffer: This form accepts a pointer and explicit byte count. Base64 is printable encoding only; it does not protect the logged data.
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LogDataHex2
void CkLogW_LogDataHex2(HCkLogW cHandle, const wchar_t *tag, const void * pByteData, unsigned long szByteData);
Introduced in version 9.5.0.82

Encodes szByteData bytes beginning at pByteData as hexadecimal text and logs the result under tag.

C++ byte buffer: This form accepts a pointer and explicit byte count. The caller must supply a valid buffer containing at least szByteData readable bytes.
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LogDataMax
void CkLogW_LogDataMax(HCkLogW cHandle, const wchar_t *tag, const wchar_t *message, int maxNumChars);
Introduced in version 9.5.0.44

Adds a tagged text value to the current context, but limits the logged value to at most the first maxNumChars characters of message.

Diagnostic previews: Use this when a value may be very large and only a leading preview is needed. The original input string is not modified.
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LogDateTime
void CkLogW_LogDateTime(HCkLogW cHandle, const wchar_t *tag, BOOL gmt);
Introduced in version 9.5.0.44

Logs the current date and time under tag using an RFC 822-style date/time representation. If gmt is TRUE, the logged time is GMT/UTC; otherwise local system time is used.

Date/time vs. timestamp: Use LogDateTime for a calendar date with timezone context. Use LogTimestamp for a time-of-day marker.
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LogError
void CkLogW_LogError(HCkLogW cHandle, const wchar_t *message);
Introduced in version 9.5.0.44

Adds message as an error entry in the current logging context.

Application diagnostics: This is application-defined logging. It is separate from LastErrorText produced by other Chilkat objects when their operations fail.
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LogHash2
void CkLogW_LogHash2(HCkLogW cHandle, const wchar_t *tag, const wchar_t *hashAlg, const void * pByteData, unsigned long szByteData);
Introduced in version 9.5.0.82

Computes a hash of szByteData bytes beginning at pByteData and logs the digest as hexadecimal text under tag. Supported values for hashAlg are SHA1, SHA256, SHA384, SHA512, and MD5.

Useful for comparison: A digest is often preferable to dumping a large binary value when the goal is to determine whether two byte sequences are identical.
Security note: MD5 and SHA1 are not suitable when cryptographic collision resistance is required. Prefer SHA-256 or stronger for security-sensitive hashing.
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LogInfo
void CkLogW_LogInfo(HCkLogW cHandle, const wchar_t *message);
Introduced in version 9.5.0.44

Adds message as an informational entry in the current logging context.

Structured tracing: Use informational entries for significant steps and decisions. Use LogData when the entry is better represented as a named value.
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LogInt
void CkLogW_LogInt(HCkLogW cHandle, const wchar_t *tag, int value);
Introduced in version 9.5.0.44

Adds the integer value to the current log under tag.

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LogInt64
void CkLogW_LogInt64(HCkLogW cHandle, const wchar_t *tag, __int64 value);
Introduced in version 9.5.0.44

Adds the signed 64-bit integer value to the current log under tag.

64-bit values: Useful for values such as large byte counts, file sizes, sequence numbers, or timestamps that can exceed ordinary integer ranges.
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LogTimestamp
void CkLogW_LogTimestamp(HCkLogW cHandle, const wchar_t *tag);
Introduced in version 9.5.0.44

Logs the current time-of-day under tag in HH:MM:SS:mmm form, where mmm represents milliseconds.

Timing note: This is a time-of-day marker, not a monotonic elapsed-time measurement.
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Deprecated

LogDataBase64 Deprecated
void CkLogW_LogDataBase64(HCkLogW cHandle, const wchar_t *tag, HCkByteData data);
Introduced in version 9.5.0.44

Encodes the supplied binary data as Base64 and adds the encoded value to the current log under tag.

Base64: Base64 makes arbitrary bytes printable in a text log. It is an encoding, not encryption.
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LogDataHex Deprecated
void CkLogW_LogDataHex(HCkLogW cHandle, const wchar_t *tag, HCkByteData data);
Introduced in version 9.5.0.44

Encodes the supplied binary data as hexadecimal text and adds the encoded value to the current log under tag.

Hex output: Hex is convenient for short protocol fields, identifiers, digests, and byte-level troubleshooting because each byte is represented by two hex digits.
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