This document discusses error handling in Visual FoxPro 9.0. It describes different types of errors that can occur, such as coding errors, environmental errors, and user errors. It then explains various methods for handling errors in Visual FoxPro, including native error handling, using ON ERROR, the Error method, TRY/CATCH blocks, and other techniques. Examples are provided to illustrate how to implement each error handling method. Related commands and functions for retrieving error details are also outlined.
SynapseIndia gives an overview on comparison in PHP & ASP.NET in Terms of Cos...SynapseIndia
SynapseIndia gives comparison in PHP & ASP.NET in aspects of Costs, Scalability & Performance. ASP.NET and PHP are equally popular web development frameworks that come equipped with a host of features to simplify web development for developers.
SynapseIndia gives an overview on comparison in PHP & ASP.NET in Terms of Cos...SynapseIndia
SynapseIndia gives comparison in PHP & ASP.NET in aspects of Costs, Scalability & Performance. ASP.NET and PHP are equally popular web development frameworks that come equipped with a host of features to simplify web development for developers.
It is a nice simple "MVC PHP Framework", which is powerful, lightweight, very flexible, transparent. One can easily modify as per their need. It is not complex or very restricted like other frameworks.
As the PHP frame work is adding value to its users. We have shown here the types of PHP, similarities between Laravel and Yii, difference between Laravel and Yii, Reason for using them and conclusion.
UI is the first thing which sells your application and it has been a while since we have thought to look for an alternative framework for developing UI other than Javascript. Suddenly the adoption of JS based framework like AngularJS, ReactJS, UI5 and D3JS have made Javascript the de-facto standard to create and build your UI. But is it the only option we have and the bigger question is why or why not some other tech stack replaces Javascript on UI.
Know the dark side of the Javascript frameworks for building UI, its limitation, its bad parts and learn to which extent you can push Javascript while developing UI.
Stay Connected with us!
Mail us: admin@ui5cn.com connect@ui5cn.com
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Phinx is one of the most popular standalone database migration tools. Learn the basic concepts of Phinx with its creator Rob Morgan. This presentation covers adding it to a project, creating new migrations and then executing them, . You are also exposed to more advanced features of Phinx and everyday use cases.
Uvod u php - Danilo Purić i Tarik ZaimovićBild_Studio
Danilo Purić i Tarik Zaimović su održali predavanje na Univerzitetu Donja Gorica. Tema predavanja je bila „Uvod u PHP“. Mlade ljude koji su prezentaciji prisustvovali su u predavanje uveli pričom o broju inžinjera u svijetu, broju kurseva iz oblasti, popularnosti ove oblasti, i sl.
A presentation on PHP's position in the enterprise, its past & present, how to get ready for developing for enterprise.
Inspired by Ivo Jansch's "PHP in the real wolrd" presentation.
Presented at SoftExpo 2010, Dhaka, Bangladesh.
”It’s all about Containers, Serverless and Reactive Programming right now! ProgSCon London will explore these trends with leading industry experts. Several talks will also feature Blockchain, Microservices and Big Data.”
You’re here at ProgSCon to hear all about the latest trends in technology, to learn about them and decide which ones to apply and figure out how. But it’s a tall order, learning to be a fully buzzword compliant developer, architect or lead, especially when What’s Hot changes on practically a daily basis.
During this talk, Trisha will give an irreverent overview of the current technical landscape and present a survival guide for those who want to stay ahead in this turbulent industry.
See also: https://trishagee.github.io/presentation/becoming_buzzword_compliant/
It is a nice simple "MVC PHP Framework", which is powerful, lightweight, very flexible, transparent. One can easily modify as per their need. It is not complex or very restricted like other frameworks.
As the PHP frame work is adding value to its users. We have shown here the types of PHP, similarities between Laravel and Yii, difference between Laravel and Yii, Reason for using them and conclusion.
UI is the first thing which sells your application and it has been a while since we have thought to look for an alternative framework for developing UI other than Javascript. Suddenly the adoption of JS based framework like AngularJS, ReactJS, UI5 and D3JS have made Javascript the de-facto standard to create and build your UI. But is it the only option we have and the bigger question is why or why not some other tech stack replaces Javascript on UI.
Know the dark side of the Javascript frameworks for building UI, its limitation, its bad parts and learn to which extent you can push Javascript while developing UI.
Stay Connected with us!
Mail us: admin@ui5cn.com connect@ui5cn.com
Youtube: https://www.youtube.com/c/UI5CommunityNetwork?sub_confirmation=1
Facebook: https://www.facebook.com/goui5cn
Twitter: https://twitter.com/ui5cn
Google+ : https://plus.google.com/+UI5CommunityNetwork
Phinx is one of the most popular standalone database migration tools. Learn the basic concepts of Phinx with its creator Rob Morgan. This presentation covers adding it to a project, creating new migrations and then executing them, . You are also exposed to more advanced features of Phinx and everyday use cases.
Uvod u php - Danilo Purić i Tarik ZaimovićBild_Studio
Danilo Purić i Tarik Zaimović su održali predavanje na Univerzitetu Donja Gorica. Tema predavanja je bila „Uvod u PHP“. Mlade ljude koji su prezentaciji prisustvovali su u predavanje uveli pričom o broju inžinjera u svijetu, broju kurseva iz oblasti, popularnosti ove oblasti, i sl.
A presentation on PHP's position in the enterprise, its past & present, how to get ready for developing for enterprise.
Inspired by Ivo Jansch's "PHP in the real wolrd" presentation.
Presented at SoftExpo 2010, Dhaka, Bangladesh.
”It’s all about Containers, Serverless and Reactive Programming right now! ProgSCon London will explore these trends with leading industry experts. Several talks will also feature Blockchain, Microservices and Big Data.”
You’re here at ProgSCon to hear all about the latest trends in technology, to learn about them and decide which ones to apply and figure out how. But it’s a tall order, learning to be a fully buzzword compliant developer, architect or lead, especially when What’s Hot changes on practically a daily basis.
During this talk, Trisha will give an irreverent overview of the current technical landscape and present a survival guide for those who want to stay ahead in this turbulent industry.
See also: https://trishagee.github.io/presentation/becoming_buzzword_compliant/
How I Learned to Stop Worrying and Love Legacy Code - Ox:Agile 2018Mike Harris
I never wrote it; everybody else did! How many times have you waded through an ageing, decaying, tangled forrest of code and wished it would just die? How many times have you heard someone say that what really needs to happen is a complete rewrite? I have heard this many times, and, have uttered that fatal sentence myself. But shouldn’t we love our legacy code? Doesn’t it represent our investment and the hard work of ourselves and our predecessors? Throwing it away is dangerous, because, before we do, we’ll need to work out exactly what it does, and we’ll need to tweeze out that critical business logic nestled in a deeply entangled knot of IF statements. It could take us years to do, and we’ll have to maintain two systems whilst we do it, inevitably adding new features to them both. Yes we get to reimplement using the latest, coolest programming language, instead of an old behemoth, but how long will our new cool language be around, and who will maintain that code, when it itself inevitably turns to legacy? We can throw our arms in the air, complaining and grumbling about how we didn’t write the code, how we would never have written it the way it is, how those that wrote it were lesser programmers, possibly lesser humans themselves, but the code still remains, staring us in the face and hanging around for longer that we could possibly imagine. We can sort it out, we can improve it, we can make it testable, and we can learn to love our legacy code.
https://www.youtube.com/watch?v=qRP45l5UugE
Simplifying debugging for multi-core Linux devices and low-power Linux clusters Rogue Wave Software
Debugging scalable hybrid and accelerated applications on the Cray XC30, CS300 with our multi-threaded debugger TotalView. Faster fault isolation, improved memory optimization, and dynamic visualization for your high performance computing apps, a solution provided by Rogue Wave Software
Hacker Halted 2014 - RDP Fuzzing And Why the Microsoft Open Protocol Specific...EC-Council
Over the past year, Tripwire Security Researchers Tyler Reguly and Andrew Swoboda have invested numerous hours into understanding the Microsoft Remote Desktop Protocol, specifically the pre-authentication portions of RDP. The Microsoft Open Protocol Specifications were heavily utilized for this projected and, while both researchers had used the specifications before, neither had fully realized their usefulness to security researchers. This session will be a discussion of The Microsoft Open Protocol Specification with RDP as the example. The culmination of the session will be the release of a new RDP Fuzzer and a discussion around the vulnerabilities it has already discovered.
Attendees can expect to walk away with a strong understanding of the Microsoft Open Protocol Specifications and how they can leverage them to build protocol implementations and fuzzers, as well as investigate inherent flaws and discover new vulnerabilities. Attendees will have a better understanding of the pre-authentication RDP connection sequence and exactly what data is exchanged and what an attacker can deduce from this communication. Finally, attendees will gain insight into new RDP vulnerabilities.
Breaking Parser Logic: Take Your Path Normalization Off and Pop 0days Out!Priyanka Aash
"We propose a new exploit technique that brings a whole-new attack surface to defeat path normalization, which is complicated in implementation due to many implicit properties and edge cases. This complication, being under-estimated or ignored by developers for a long time, has made our proposed attack vector possible, lethal, and general. Therefore, many 0days have been discovered via this approach in popular web frameworks written in trending programming languages, including Python, Ruby, Java, and JavaScript.
Being a very fundamental problem that exists in path normalization logic, sophisticated web frameworks can also suffer. For example, we've found various 0days on Java Spring Framework, Ruby on Rails, Next.js, and Python aiohttp, just to name a few. This general technique can also adapt to multi-layered web architecture, such as using Nginx or Apache as a proxy for Tomcat. In that case, reverse proxy protections can be bypassed. To make things worse, we're able to chain path normalization bugs to bypass authentication and achieve RCE in real world Bug Bounty Programs. Several scenarios will be demonstrated to illustrate how path normalization can be exploited to achieve sensitive information disclosure, SMB-Relay and RCE.
Understanding the basics of this technique, the audience won't be surprised to know that more than 10 vulnerabilities have been found in sophisticated frameworks and multi-layered web architectures aforementioned via this technique."
Fuzzing and You: Automating Whitebox TestingNetSPI
Fuzzing is easy, but getting useful information from fuzzing isn’t. ‘Spray and pray’ might get some results, but a set of well-designed tests will get much better results faster. Unfortunately, the job doesn’t end there. Fuzzing doesn’t find vulnerabilities; fuzzing finds unexpected behavior. Interpreting that unexpected behavior relies on understanding the application you’re fuzzing and the tests you’ve designed. This presentation will discuss techniques for creating tests targeted towards uncovering specific behavior, including authorization bypasses, directory traversals, and buffer overflows.
CNIT 127: Ch 8: Windows overflows (Part 2)Sam Bowne
Slides for a college course at City College San Francisco. Based on "The Shellcoder's Handbook: Discovering and Exploiting Security Holes ", by Chris Anley, John Heasman, Felix Lindner, Gerardo Richarte; ASIN: B004P5O38Q.
Instructor: Sam Bowne
Class website: https://samsclass.info/127/127_S17.shtml
JavaOne 2010: Top 10 Causes for Java Issues in Production and What to Do When...srisatish ambati
Top 10 Causes for Java Issues in Production and What to Do When Things Go Wrong
JavaOne 2010.
Abstract: It's Friday evening and you hear the first rumble . . . one java node has become slightly unresponsive. You lookup the process, get a thread dump, and for good measure restart it at 8 p.m. Saturday afternoon is when you realize that other nodes have caught the flu and you get the ugly call from the customer. In a matter of hours, you're on that conference bridge with support groups of different packages and Java vendors and one of your uberarchitects. Yes, production instances are up and down, and restarting like there's no tomorrow. Here's an accumulated compendium of the op 10 things that can cause Java production heartburn and what to do when your Java production is on fire. And yes, please have your tools belt on.
Speaker(s):
Cliff Click, Azul Systems, Distinguished Engineer
SriSatish Ambati, Azul Systems, Performance Engineer
Slides for a college course at City College San Francisco. Based on "The Shellcoder's Handbook: Discovering and Exploiting Security Holes ", by Chris Anley, John Heasman, Felix Lindner, Gerardo Richarte; ASIN: B004P5O38Q.
Instructor: Sam Bowne
Class website: https://samsclass.info/127/127_F18.shtml
How to improve your code quality? The answer is continuous refactoring. Learn more about refactoring. Know the most frequent code smells (antipatterns), telling when to refactor. Go through the catalog of well-known refactorings, telling how to improve your code.
Similar to Error handling in visual fox pro 9 (20)
2. Who Am I
• President F1 Technologies
• Visual FoxExpress Developer
• Visual FoxPro Dinosaur
• mikefeltman@f1tech.com
• www.f1tech.com
• www.f1technologies.blogspot.com
3. Agenda
• Errors Happen
• Types of Errors
• Error Trapping Methods
• Dealing with Errors
• Combining Methods
4. Errors Happen
• Virtually All Programs Have
Errors
• All Applications – even “bug
free” ones - can encounter an
error
5. Types of Errors
• Coding Errors
– Syntax Errors, Data Type Mismatch, Invalid # of
Parameters, etc.
• Environmental Errors
– File Corruption, Printer not ready, Resource not Available,
File not Found,
• User Errors
– Duplicate keys, invalid values
6. Types of Error Trapping
• Native
• ON ERROR
• Error Method
• TRY/CATCH
• OTHER
7. Native Error Handling
• At Design Time – Cancel, Ignore or Suspend
• At Run Time – Cancel or Ignore
8. ON ERROR
• Oldest method in the book
• Format:
– ON ERROR <action>
– ON ERROR *
– ON ERROR DO ErrorHandler WITH…
– ON ERROR llError = .T.
– ON ERROR goErrorHandler.DealWithIt(…)
9. ON ERROR
• Pros • Cons
– Centralized Mechanism – Removed from offending
– Catch all code
– Supports RETRY – Forces Monolithic Style
– Supports RETURN of error handling
– May require additional
inline detection of error
states in application
code
– Difficult to deal with
specific scenarios
11. The Error Event
• Added in VFP 3.0
• Native to all VFP Objects
• Error(nError, cMethod, nLine)
12. The Error Event
• Pros • Leads to duplicate code
– Localized to offending • Can Require Lengthy DO
object CASE constructs
– Supports RETRY
• Turns off ON ERROR error
– Supports RETURN
handling
• May require additional
inline detection of error
states in application
code
15. TRY CATCH
• Pros • Cons
– Deal w/ errors at the – Adapting Existing Apps
source – Can make debugging
– Less Cumbersome more difficult
– Less Code in specific – No RETRY or RETURN TO
routines
– Easier recovery in some
instances
– Nests gracefully
16. The Exception Object & Catch
• CATCH always creates a base class exception
• Key Properties:
ErrorNo Procedure
Message UserValue
LineContents StackLevel
Details
17. The Throw Command
• THROW <expression>
• Creates an exception
• Expression is placed in user value
• Can be used any time a TRY CATCH is in Effect
• SYS(2410) can be used to detect TRY/CATCH
19. OTHER ERROR TRAPPING
• TABLEUPDATE() ERRORS
– Field Rule Violated 1582
– Record Rule Violated 1583
– Trigger Failed 1539
– Unique Index Violated 1884
– Update Conflict 1585
• SQLEXEC(), SQLCOMMIT(), SQLCONNECT(), etc. all
populate the AERROR array.
20. Connectivity Errors
• Connectivity Error 1526
• AERROR() will contain the back-end error(s)
– Column 3: ODBC Error Message
– Column 4: ODBC State
– Column 5: ODBC Error Number
– Column 6: Connection Handle
• AERROR() can return multiple rows
21. Mixing & Matching
• If error is w/in object error event takes
precedence
• If error is in TRY/CATCH structured error
handling takes precedence
• If error is in procedural code ON ERROR takes
precedence
• Samples: Error10 - 16
22. Related Commands & Functions
• Error Details • More Info
– MESSAGE(), MESSAGE(1) – LIST STATUS
– SYS(2018) – LIST MEMORY
– AERROR() – LIST OBJECTS
• Error Location • Environment
– LINENO() – SYS(5) + CURDIR()
– PROGRAM(), SYS(16) – SET(“PATH”)
– ACALLSTACKINFO() – SET(“CLASSLIB”)
– SET(“PROCEDURE”)
– SYS(2019)
– OS()
– Version()
– SYS(0)
23. Conclusion
• VFP Has a lot of ways to deal with errors
• Mixing and Matching the techniques lets you
take advantage of all of them
• More Info:
– VFP Best Practices from Henztenwerke (Rick
Schummer)
– Structured Error Handling Topic on Fox.wikis.com
by Randy Pearson
– CoDe Focus VFP 8 Issue (CodeMagazine.Com)