Log C Reference Documentation
Log
Current Version: 11.5.0
Chilkat.Log
Use
Add informational messages, error messages, and tagged text values to
explain what the application is doing.
Log integers, 64-bit integers, timestamps, and date/time values when
tracing state changes or timing-sensitive workflows.
Record binary data as Base64, hex, or shortened previews so byte-level
values can be inspected safely in text logs.
Compute and log hashes of data when comparing content, verifying
transformations, or avoiding full data dumps.
Clear the log and continue building new diagnostic output during
repeated operations or test runs.
For an extended overview, see
Log Class Overview.
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
EnterContext and LeaveContext to group log
entries under readable operation names.
Messages and errors
Numbers and timestamps
Binary diagnostics
Hash logging
Clear and reuse
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
HCkLog instance = CkLog_Create(); // ... CkLog_Dispose(instance);
Creates an instance of the HCkLog object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.
Objects created by calling CkLog_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 CkLog_Dispose.
Properties
DebugLogFilePath
void CkLog_putDebugLogFilePath(HCkLog cHandle, const char *newVal);
const char *CkLog_debugLogFilePath(HCkLog 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.
LastErrorHtml
const char *CkLog_lastErrorHtml(HCkLog 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.
topLastErrorText
const char *CkLog_lastErrorText(HCkLog 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.
LastErrorXml
const char *CkLog_lastErrorXml(HCkLog 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.
topLastMethodSuccess
void CkLog_putLastMethodSuccess(HCkLog 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.
Utf8
void CkLog_putUtf8(HCkLog cHandle, BOOL newVal);
When set to TRUE, all const char * arguments and return values are interpreted as UTF-8 strings. When set to FALSE, they are interpreted as ANSI strings.
In Chilkat v11.0.0 and later, the default value is TRUE. Before v11.0.0, it was FALSE.
VerboseLogging
void CkLog_putVerboseLogging(HCkLog 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.
Version
Methods
Clear
Clears all existing log entries and starts a new log whose top-level context is named initialTag.
Log* methods. The completed structured log can be inspected through the Log object's diagnostic text, such as LastErrorText.EnterContext
Begins a nested logging context named tag. Entries written after this call are grouped inside the new context until a matching LeaveContext is called.
EnterContext with LeaveContext. Contexts may be nested to reflect operation hierarchy.LeaveContext
Ends the current nested logging context and returns logging to its parent context.
LogData
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.
LogDataBase64_2
Encodes szByteData bytes beginning at pByteData as Base64 and logs the result under tag.
LogDataHex2
Encodes szByteData bytes beginning at pByteData as hexadecimal text and logs the result under tag.
szByteData readable bytes.LogDataMax
Adds a tagged text value to the current context, but limits the logged value to at most the first maxNumChars characters of message.
LogDateTime
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.
LogDateTime for a calendar date with timezone context. Use LogTimestamp for a time-of-day marker.LogError
Adds message as an error entry in the current logging context.
LastErrorText produced by other Chilkat objects when their operations fail.LogHash2
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.
MD5 and SHA1 are not suitable when cryptographic collision resistance is required. Prefer SHA-256 or stronger for security-sensitive hashing.LogInfo
Adds message as an informational entry in the current logging context.
LogData when the entry is better represented as a named value.LogInt
Adds the integer value to the current log under tag.
LogInt64
Adds the signed 64-bit integer value to the current log under tag.
LogTimestamp
Logs the current time-of-day under tag in HH:MM:SS:mmm form, where mmm represents milliseconds.
Deprecated
LogDataBase64 Deprecated
Encodes the supplied binary data as Base64 and adds the encoded value to the current log under tag.
LogDataHex Deprecated
Encodes the supplied binary data as hexadecimal text and adds the encoded value to the current log under tag.