Within the context of MVS (A number of Digital Storage) programs, particular codes, usually numerical, are utilized to suggest irregular termination of a program. These codes, known as ABEND (ABnormal ENDing) codes, present a way of figuring out the kind and explanation for program failure. For instance, an S0C4 ABEND code generally signifies a safety exception, that means a program tried to entry reminiscence it was not licensed to make use of.
Understanding these termination codes is essential for debugging and resolving points in MVS functions. Analyzing them permits system programmers and software builders to rapidly pinpoint the placement and nature of the issue, saving appreciable time and assets within the debugging course of. Traditionally, these codes have been a basic a part of MVS diagnostics, evolving alongside the working system itself and sustaining their significance in fashionable mainframe environments.
The next sections will delve into widespread ABEND codes encountered in MVS, their meanings, and techniques for resolving them. An in depth understanding of those codes and related debugging strategies is crucial for sustaining the soundness and efficiency of MVS-based functions.
1. Error Identification
Error identification within the MVS setting is essentially linked to ABEND (ABnormal ENDing) codes. These codes function the first mechanism for signaling and categorizing program failures, offering important info for diagnostics and drawback decision.
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ABEND Code as a Categorization Device
ABEND codes present a standardized technique of categorizing errors. Every code corresponds to a selected kind of failure, corresponding to reminiscence entry violations (S0C4), invalid operations (0C1), or knowledge exceptions (0CB). This categorization permits system programmers and builders to rapidly slim the scope of investigation. For instance, an ABEND code of U4039 would possibly point out an issue with a selected subsystem or user-written routine, enabling fast give attention to that space.
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Location and Contextual Clues
Past the code itself, this system standing phrase (PSW) and register contents on the time of the ABEND supply beneficial clues concerning the location and context of the error. The PSW pinpoints the instruction that was executing when the ABEND occurred, whereas register contents present details about the info being processed. Contemplate a situation the place an S0C7 ABEND (knowledge exception) happens. The PSW and register values can reveal the particular knowledge discipline that triggered the exception and this system logic that led to its use.
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Influence on System Stability
The immediate and correct identification of errors by ABEND codes is essential for sustaining system stability. By rapidly recognizing and addressing the basis explanation for failures, potential cascading issues could be prevented. As an illustration, if a program repeatedly ABENDs on account of a reminiscence leak (indicated by particular patterns within the ABEND codes and system logs), fast motion is critical to keep away from useful resource exhaustion and potential system-wide affect.
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Facilitating Debugging and Decision
ABEND codes are a crucial start line for the debugging course of. They supply a concise abstract of the issue, directing builders to the related code sections and knowledge buildings. Debugging instruments and strategies, corresponding to dumps and tracing, could be employed extra successfully when guided by the knowledge offered by the ABEND code. Figuring out an 0C4 ABEND rapidly results in the investigation of reminiscence entry patterns, doubtlessly revealing points like buffer overflows or pointer errors.
In essence, ABEND codes are the cornerstone of error identification inside MVS. Their function extends past merely signaling a failure; they supply crucial context, categorization, and course for environment friendly debugging and system upkeep. The excellent understanding and efficient utilization of those codes are important for making certain the dependable operation of MVS-based functions and programs.
2. Diagnostic Device
ABEND codes within the MVS setting function a crucial diagnostic instrument, offering important info for figuring out, analyzing, and resolving program failures. The data encoded inside these codes guides system programmers and software builders in direction of the supply of errors, enabling environment friendly troubleshooting and system upkeep.
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ABEND Codes as Preliminary Drawback Indicators
ABEND codes are usually the primary indication of an issue in an MVS system. They instantly alert directors to the truth that a program has terminated unexpectedly. The particular code itself offers a broad categorization of the failure kind. As an illustration, an S0C1 ABEND signifies an operation exception, suggesting an try and execute an invalid instruction. This preliminary indication is significant for focusing diagnostic efforts.
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Guiding the Debugging Course of
The particular ABEND code directs the next debugging course of. Figuring out the kind of ABEND helps decide which debugging instruments and strategies are most applicable. For instance, an S0C4 ABEND, signaling a safety exception, prompts investigation into reminiscence entry patterns and potential buffer overflows. This would possibly contain inspecting reminiscence dumps, reviewing code logic associated to pointer manipulation, and using debugging instruments to hint reminiscence entry violations. The ABEND code acts as a roadmap for the diagnostic journey.
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Contextual Data through System Dumps
System dumps, triggered by ABENDs, present a snapshot of the system’s state on the time of failure. These dumps include reminiscence contents, register values, and different contextual info that may be essential for understanding the reason for the ABEND. For instance, a dump following an 0C7 ABEND (knowledge exception) would possibly reveal the invalid knowledge that triggered the exception and this system logic that tried to course of it. Deciphering these dumps requires a radical understanding of MVS structure and program execution.
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Historic Evaluation and Pattern Identification
ABEND codes will also be used for historic evaluation and development identification. By monitoring the frequency and patterns of particular ABENDs, directors can determine recurring issues or underlying system points. For instance, a constant sample of ABENDs associated to a selected subsystem would possibly point out a necessity for software program updates, {hardware} upgrades, or configuration modifications. This proactive method helps stop future failures and keep system stability.
The effectiveness of ABEND codes as a diagnostic instrument hinges on the power to interpret them precisely and leverage the related info for focused debugging. Their presence triggers a scientific technique of investigation, using system dumps, debugging instruments, and historic evaluation to pinpoint the basis explanation for program failures and make sure the continued clean operation of MVS environments.
3. System Stability
System stability in an MVS setting is inextricably linked to the prevalence and administration of ABEND (ABnormal ENDing) codes. These codes, signifying program termination on account of errors, immediately affect the reliability and operational integrity of the system. Efficient dealing with of ABENDs is essential for sustaining a secure and predictable computing setting.
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ABEND Codes as Indicators of Systemic Points
Particular person ABEND codes can usually be symptomatic of broader systemic issues. For instance, a recurring S0C4 ABEND (safety exception) throughout a number of functions would possibly level to a vulnerability within the working system’s reminiscence administration or a flaw in a shared library. Figuring out and resolving the underlying trigger, fairly than merely addressing particular person cases of the ABEND, is crucial for long-term stability. The frequency and sample of ABENDs can function an early warning system for potential instability.
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Influence on Batch Processing and Crucial Purposes
Unresolved ABENDs can severely disrupt batch processing and the execution of crucial functions. Batch jobs that terminate prematurely on account of ABENDs can result in incomplete knowledge processing, inaccurate reporting, and delays in enterprise operations. Equally, ABENDs in on-line transaction processing (OLTP) programs can lead to knowledge corruption, service interruptions, and monetary losses. Prioritizing the decision of ABENDs in these crucial areas is paramount for sustaining enterprise continuity and knowledge integrity.
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Useful resource Administration and System Efficiency
ABENDs can negatively affect useful resource administration and system efficiency. A program that ABENDs would possibly depart assets allotted however unused, resulting in useful resource rivalry and lowered general system throughput. Frequent ABENDs also can set off extreme paging and swapping, additional degrading efficiency. Effectively diagnosing and resolving ABENDs helps reclaim these assets and optimize system efficiency. For instance, an ABEND attributable to a reminiscence leak could be recognized and addressed to forestall gradual useful resource exhaustion.
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The Position of Monitoring and Automated Response
Proactive monitoring for ABENDs and automatic response mechanisms are important for sustaining system stability. Actual-time monitoring instruments can detect ABENDs as they happen and alert directors, enabling speedy intervention. Automated response scripts could be configured to restart failed jobs, reallocate assets, and even isolate problematic functions. This proactive method minimizes the affect of ABENDs on system stability and reduces the necessity for guide intervention. The flexibility to mechanically determine and handle ABENDs is a key part of a resilient and secure MVS setting.
In abstract, ABEND codes will not be merely remoted incidents of program failure; they’re indicators of potential systemic points that may compromise system stability. Proactive monitoring, environment friendly prognosis, and immediate decision of ABENDs are important for sustaining a dependable and predictable MVS setting, making certain the sleek operation of crucial functions and preserving knowledge integrity.
4. Debugging Course of
The debugging course of throughout the MVS setting is inextricably linked to ABEND (ABnormal ENDing) codes. The prevalence of an ABEND alerts the termination of a program on account of an error, and the corresponding ABEND code serves because the preliminary indicator of the character of the issue. This code initiates and guides the debugging course of, offering a crucial start line for figuring out the basis explanation for this system failure. With out the ABEND code, the debugging job can be considerably extra advanced, requiring a broader and fewer targeted seek for potential errors. The code features as a vital filter, directing debugging efforts in direction of particular areas of the system. For instance, if an ABEND code S0C7 is issued, it suggests an information exception, instantly focusing the debugging course of on knowledge dealing with and sort conversion operations throughout the failing program.
The ABEND code’s worth extends past preliminary error identification. It dictates the debugging strategies employed. An ABEND code corresponding to S0C4, indicating a safety exception, suggests an try and entry reminiscence outdoors this system’s allotted area. The debugging course of, on this case, would probably contain inspecting reminiscence dumps to determine the handle being accessed, using tracing instruments to comply with this system’s reminiscence entry patterns, and analyzing the code for potential buffer overflows or incorrect pointer arithmetic. The ABEND code, due to this fact, dictates which instruments and strategies are most related and environment friendly for resolving the error. Contemplate a situation the place a batch job constantly terminates with an ABEND code U4083. The debugging course of would then entail inspecting the user-defined code or subsystem related to that particular U-code, fairly than performing a common system-wide investigation.
In abstract, ABEND codes are an integral part of the MVS debugging course of. They operate because the preliminary diagnostic clue, categorizing the error and offering course for subsequent investigation. The ABEND code dictates the choice of applicable debugging instruments and strategies, and in the end, influences the effectivity and effectiveness of your complete debugging course of. A complete understanding of ABEND codes and their corresponding error circumstances is due to this fact important for any MVS system programmer or software developer chargeable for sustaining system stability and program reliability.
5. Code Interpretation
Code interpretation is prime to understanding irregular termination codes throughout the MVS setting. ABEND codes, by their very nature, are symbolic representations of particular system or software errors. With out correct interpretation, these codes are merely numerical or alphanumeric strings, devoid of sensible that means. The flexibility to decipher the meant message conveyed by an ABEND code is the essential first step in diagnosing and resolving program failures. A direct cause-and-effect relationship exists: the particular error triggers the ABEND, and the ensuing code is the system’s manner of speaking the kind of error that occurred. An S0C1 ABEND, as an example, alerts an operation exception. Its right interpretation directs consideration to potential points with instruction execution, corresponding to an invalid opcode or an try and execute knowledge as code.
The significance of code interpretation is additional underscored by the complexity inherent in MVS programs. The working system, its subsystems, and particular person functions generate a big selection of ABEND codes, every representing a novel error situation. Correct interpretation requires a deep understanding of MVS structure, programming languages, and the particular software’s logic. Contemplate a U4038 ABEND inside a COBOL software; it is user-defined and requires accessing the appliance’s documentation or supply code to find out its that means. This emphasizes that interpretation is context-dependent and sometimes necessitates inspecting application-specific particulars past the final MVS error documentation. Moreover, the diagnostic course of steadily entails correlating the ABEND code with system logs, reminiscence dumps, and different debugging info. A easy code might need totally different root causes that calls for superior interpretation to pick the correct one.
In conclusion, code interpretation kinds the cornerstone of efficient MVS troubleshooting. The proper understanding of ABEND codes transforms them from cryptic error messages into beneficial diagnostic clues. Whereas challenges stay in deciphering application-specific codes and correlating them with advanced system conduct, the power to precisely interpret these codes stays important for sustaining system stability and resolving software failures. This ability is integral to the broader theme of MVS programs administration and requires steady studying and adaptation to the ever-evolving panorama of mainframe expertise.
6. Drawback Decision
Drawback decision within the MVS setting is essentially reliant on understanding ABEND (ABnormal ENDing) codes. An ABEND code is generated upon program termination on account of an error, and this code offers the preliminary, essential clue concerning the character of the issue. With out ABEND codes, the diagnostic course of can be considerably extra advanced, requiring a broad and sometimes inefficient seek for the supply of the error. The ABEND code immediately influences the troubleshooting method, dictating which instruments and strategies are most related. For instance, a safety exception, indicated by an S0C4 ABEND, necessitates examination of reminiscence entry patterns and potential buffer overflows. On this occasion, the issue decision technique would give attention to reminiscence dumps, tracing instruments, and code evaluation to determine the invalid reminiscence entry that triggered the ABEND.
The connection between ABEND codes and drawback decision extends past preliminary error identification. Contemplate a situation the place a batch job constantly terminates with a U0408 ABEND. This user-defined code alerts an issue particular to that software or subsystem. The issue decision course of would then contain consulting the appliance’s documentation or contacting the builders to grasp the that means of the U0408 code and the circumstances beneath which it’s generated. Moreover, system logs and application-specific hint recordsdata can be examined to determine the exact sequence of occasions main as much as the ABEND. Profitable drawback decision, due to this fact, requires not solely understanding the final classes of ABEND codes but in addition the power to interpret application-specific codes and combine info from varied diagnostic sources. In impact, efficient drawback decision for MVS software’s crucial providers, relies upon closely on the troubleshooting for ABEND codes.
In conclusion, ABEND codes are an indispensable part of drawback decision inside MVS environments. They supply the preliminary diagnostic info that guides the next troubleshooting steps. Whereas the interpretation of ABEND codes could be difficult, particularly when coping with application-specific codes or advanced system interactions, a radical understanding of those codes and their implications is crucial for sustaining system stability and making certain the dependable operation of MVS functions. Efficiently resolving ABEND codes is a steady course of that mixes technical experience, analytical expertise, and a deep understanding of the MVS ecosystem.
7. Software Integrity
Software integrity throughout the MVS setting is immediately and considerably impacted by ABEND (ABnormal ENDing) codes. The prevalence of an ABEND signifies a program’s surprising termination on account of an error. The kind of error, as indicated by the ABEND code, immediately correlates with potential threats to software knowledge and operational continuity. As an illustration, an ABEND attributable to a reminiscence entry violation (S0C4) can corrupt crucial knowledge buildings, resulting in inconsistent software state and doubtlessly invalid outputs. Equally, an ABEND arising from a divide-by-zero error (0C9) would possibly lead to inaccurate calculations and compromised knowledge accuracy. Subsequently, managing and deciphering ABEND codes shouldn’t be merely a debugging train however a basic apply for safeguarding software integrity. The systematic evaluation and backbone of ABENDs contribute on to the reliability and trustworthiness of functions operating on MVS programs. Contemplate a web-based banking software. An ABEND throughout a transaction might lead to an incomplete switch, resulting in monetary discrepancies and a lack of buyer confidence. Correct ABEND dealing with procedures, together with fast rollback and error logging, are important for stopping such integrity breaches.
Moreover, the absence of strong ABEND dealing with mechanisms can result in insidious integrity points that is probably not instantly obvious. For instance, an software with poorly outlined error restoration routines would possibly proceed processing regardless of encountering non-fatal ABENDs, resulting in gradual knowledge corruption. That is significantly regarding in batch processing environments the place giant volumes of information are processed with out real-time monitoring. In such instances, the affect of undetected ABENDs could be amplified, leading to important knowledge inaccuracies and doubtlessly expensive errors. The proactive monitoring and evaluation of ABEND occurrences, mixed with the implementation of complete error dealing with procedures, are important for mitigating these dangers. An actual-world instance of that is stock administration; if ABEND shouldn’t be dealt with nicely, the stock system might have the fallacious quantity, and will trigger the corporate loss in revenues.
In abstract, software integrity is critically depending on the efficient administration and interpretation of ABEND codes throughout the MVS setting. These codes function essential indicators of potential threats to knowledge consistency, operational reliability, and general software trustworthiness. Proactive monitoring, systematic evaluation, and strong error dealing with are important practices for mitigating the dangers related to ABENDs and making certain the continued integrity of MVS functions. The failure to handle ABENDs successfully can have far-reaching penalties, impacting enterprise operations, monetary stability, and buyer confidence. Thus, software integrity could be maintained by the right code interpretation and dealing with.
8. Useful resource Administration
Useful resource administration in MVS (A number of Digital Storage) is immediately affected by ABEND (ABnormal ENDing) codes. An ABEND signifies {that a} program terminated unexpectedly, usually leaving allotted assets in an indeterminate state. These assets, corresponding to reminiscence, datasets, and locks, is probably not launched correctly, resulting in useful resource rivalry and general system degradation. Subsequently, an understanding of ABEND codes is crucial for figuring out and resolving useful resource administration points. The particular ABEND code can present beneficial insights into the kind of useful resource that was not launched and the circumstances surrounding the failure. As an illustration, an ABEND indicating a dataset entry error would possibly recommend that the dataset was left locked, stopping different packages from accessing it. Equally, an ABEND related to reminiscence allocation might level to a reminiscence leak, the place allotted reminiscence shouldn’t be freed, ultimately resulting in system instability. Environment friendly useful resource administration inside MVS necessitates each the prevention of ABENDs by strong programming practices and the speedy decision of ABEND-related useful resource points after they happen.
The sensible significance of this understanding lies within the means to attenuate system downtime and optimize useful resource utilization. When an ABEND happens, system directors and software builders should be capable of rapidly diagnose the issue and take corrective motion. This entails analyzing the ABEND code, inspecting system logs, and doubtlessly debugging the failing program. By understanding the connection between ABEND codes and useful resource administration, directors can develop automated procedures for detecting and resolving useful resource leaks, releasing locked datasets, and restarting failed packages. For instance, automated scripts could be created to observe the system for particular ABEND codes and mechanically launch assets that had been held by the terminated program. This reduces the necessity for guide intervention and ensures that assets can be found for different functions. Actual-world instance is that ABENDs ought to by no means eat system’s assets.
In conclusion, ABEND codes are an necessary aspect in useful resource administration throughout the MVS setting. Their correct interpretation and dealing with is essential for sustaining system stability, optimizing useful resource utilization, and minimizing downtime. The challenges lie within the complexity of MVS programs, the big variety of ABEND codes, and the necessity for specialised expertise to diagnose and resolve resource-related points. Nonetheless, by specializing in preventative measures, growing automated response mechanisms, and fostering experience in ABEND evaluation, organizations can successfully handle assets of their MVS environments and make sure the dependable operation of crucial functions. The connection between them performs pivotal half within the advanced programs.
Steadily Requested Questions
This part addresses widespread inquiries regarding ABEND (ABnormal ENDing) codes throughout the MVS (A number of Digital Storage) setting. The data offered is meant to make clear the character and significance of those codes for system directors and software builders.
Query 1: What’s the main goal of an ABEND code in MVS?
The first goal of an ABEND code is to point the particular motive for the irregular termination of a program. It serves because the preliminary diagnostic clue, offering a categorized illustration of the error that precipitated this system failure.
Query 2: The place can a complete record of MVS ABEND codes and their meanings be discovered?
IBM documentation, particularly the “MVS System Codes” guide, offers an in depth itemizing of ABEND codes and their corresponding meanings. On-line IBM Data Facilities additionally include this info, usually up to date with the newest code definitions.
Query 3: How do ABEND codes support within the debugging course of?
ABEND codes present a place to begin for debugging by narrowing the scope of the investigation. By figuring out the kind of error that occurred, the code directs builders to the related code sections and debugging instruments crucial for resolving the issue. This helps to focus debugging efforts effectively.
Query 4: Are all ABEND codes generated by the working system itself?
No. Whereas the working system generates many ABEND codes, functions also can challenge user-defined ABEND codes (U-codes) to sign application-specific errors. These U-codes are usually documented throughout the software’s technical specs.
Query 5: What’s the significance of the “S” prefix in some ABEND codes, corresponding to S0C4?
The “S” prefix signifies that the ABEND was issued by the system itself, fairly than by a person program. The numeric portion of the code (e.g., 0C4) additional specifies the kind of system error that occurred.
Query 6: How can ABEND codes be used to enhance system stability and reliability?
By monitoring the frequency and patterns of particular ABEND codes, directors can determine recurring issues or underlying system points. This permits for proactive interventions, corresponding to software program updates, {hardware} upgrades, or configuration modifications, to forestall future failures and improve general system stability.
The correct interpretation and efficient administration of ABEND codes are important for sustaining a secure and dependable MVS setting. Understanding these codes permits environment friendly drawback prognosis, focused debugging, and proactive system upkeep.
The next article sections will discover superior debugging strategies and techniques for stopping widespread ABENDs in MVS functions.
MVS ABEND Code Dealing with
The next ideas are designed to optimize ABEND code evaluation and backbone inside MVS environments, contributing to enhanced system stability and software reliability. Adherence to those practices minimizes downtime and facilitates environment friendly troubleshooting.
Tip 1: Set up a Standardized ABEND Code Documentation System:
Preserve a complete, readily accessible repository of ABEND codes, together with IBM system codes and any application-specific U-codes. This documentation ought to embrace code descriptions, potential causes, and advisable corrective actions. This centralization streamlines the diagnostic course of and reduces reliance on particular person experience.
Tip 2: Implement Proactive ABEND Monitoring and Alerting:
Deploy monitoring instruments that mechanically detect ABEND occurrences and set off alerts. Configure thresholds based mostly on severity and frequency to prioritize crucial points. Combine this monitoring with current system administration frameworks for centralized visibility.
Tip 3: Develop Standardized ABEND Evaluation Procedures:
Create step-by-step procedures for analyzing ABENDs, together with steerage on inspecting system logs, reminiscence dumps, and software hint recordsdata. Guarantee these procedures are well-documented and available to all related personnel. Standardizing the evaluation course of ensures consistency and reduces the chance of overlooking crucial info.
Tip 4: Leverage System Dumps for Detailed ABEND Evaluation:
System dumps present a snapshot of the system’s state on the time of the ABEND. Learn to interpret these dumps to determine the basis explanation for the failure. Deal with inspecting register contents, reminiscence places, and this system standing phrase (PSW) to pinpoint the precise instruction that triggered the ABEND.
Tip 5: Prioritize ABEND Prevention By means of Rigorous Code Evaluate:
Implement thorough code evaluate processes to determine potential sources of ABENDs, corresponding to buffer overflows, reminiscence leaks, and invalid pointer arithmetic. Implement coding requirements that promote strong error dealing with and stop widespread programming errors. This proactive method reduces the variety of ABENDs that happen within the first place.
Tip 6: Set up a Data Base of Beforehand Resolved ABENDs:
Preserve a searchable database of beforehand encountered ABENDs, their root causes, and the steps taken to resolve them. This information base can function a beneficial useful resource for troubleshooting recurring points and accelerating the diagnostic course of. Encourage information sharing amongst group members to enhance general ABEND dealing with experience.
Adherence to those ideas will enhance ABEND administration practices, resulting in decreased system downtime, improved software reliability, and extra environment friendly troubleshooting efforts. Investing in these practices is crucial for sustaining a secure and productive MVS setting.
The concluding part will summarize the important thing advantages of efficient ABEND administration and spotlight future traits in MVS system diagnostics.
Conclusion
This exploration has underscored the crucial function of irregular termination codes throughout the MVS setting. Evaluation has revealed that understanding what the ABEND codes are in MVS is crucial for correct prognosis, environment friendly debugging, and proactive system upkeep. A complete grasp of those codes, together with their underlying causes and related decision methods, considerably impacts software integrity, useful resource administration, and general system stability.
Continued vigilance in monitoring, analyzing, and addressing ABEND occurrences is paramount for sustaining a sturdy and dependable MVS infrastructure. As mainframe environments evolve, a dedication to honing experience in ABEND code interpretation and integrating superior diagnostic instruments can be essential for navigating future challenges and making certain the continued success of mission-critical functions. The proactive administration of irregular termination codes should stay a core competency for all stakeholders concerned in MVS system administration and software growth.
