Search Results

Search found 44747 results on 1790 pages for 'breadth first'.

Page 88/1790 | < Previous Page | 84 85 86 87 88 89 90 91 92 93 94 95  | Next Page >

  • removeFirst and addLast methods of LinkedList Class are Unknown

    - by user318068
    I have a problem with my code in C# . if i click in compiler button , I get the following errors 'System.Collections.Generic.LinkedList<int?>' does not contain a definition for 'removeFirst' and no extension method 'removeFirst' accepting a first argument of type 'System.Collections.Generic.LinkedList<int?>' could be found (are you missing a using directive or an assembly reference?). and 'System.Collections.Generic.LinkedList<Hanoi_tower.Sol>' does not contain a definition for 'addLast' and no extension method 'addLast' accepting a first argument of type 'System.Collections.Generic.LinkedList<Hanoi_tower.Sol>' could be found (are you missing a using directive or an assembly reference?) This is my program using System.; using System.Collections.Generic; using System.Linq; using System.Text; namespace Hanoi_tower { public class Sol { public LinkedList<int?> tower1 = new LinkedList<int?>(); public LinkedList<int?> tower2 =new LinkedList<int?>(); public LinkedList<int?> tower3 =new LinkedList<int?>(); public int depth; public LinkedList<Sol> neighbors; public Sol(LinkedList<int?> tower1, LinkedList<int?> tower2, LinkedList<int?> tower3) { this.tower1 = tower1; this.tower2 = tower2; this.tower3 = tower3; neighbors = new LinkedList<Sol>(); } public virtual void getneighbors() { Sol temp = this.copy(); Sol neighbor1 = this.copy(); Sol neighbor2 = this.copy(); Sol neighbor3 = this.copy(); Sol neighbor4 = this.copy(); Sol neighbor5 = this.copy(); Sol neighbor6 = this.copy(); if (temp.tower1.Count != 0) { if (neighbor1.tower2.Count != 0) { if (neighbor1.tower1.First.Value < neighbor1.tower2.First.Value) { neighbor1.tower2.AddFirst(neighbor1.tower1.RemoveFirst); neighbors.AddLast(neighbor1); } } else { neighbor1.tower2.AddFirst(neighbor1.tower1.RemoveFirst()); neighbors.AddLast(neighbor1); } if (neighbor2.tower3.Count != 0) { if (neighbor2.tower1.First.Value < neighbor2.tower3.First.Value) { neighbor2.tower3.AddFirst(neighbor2.tower1.RemoveFirst()); neighbors.AddLast(neighbor2); } } else { neighbor2.tower3.AddFirst(neighbor2.tower1.RemoveFirst()); neighbors.AddLast(neighbor2); } } //------------- if (temp.tower2.Count != 0) { if (neighbor3.tower1.Count != 0) { if (neighbor3.tower2.First.Value < neighbor3.tower1.First.Value) { neighbor3.tower1.AddFirst(neighbor3.tower2.RemoveFirst()); neighbors.AddLast(neighbor3); } } else { neighbor3.tower1.AddFirst(neighbor3.tower2.RemoveFirst()); neighbors.AddLast(neighbor3); } if (neighbor4.tower3.Count != 0) { if (neighbor4.tower2.First.Value < neighbor4.tower3.First.Value) { neighbor4.tower3.AddFirst(neighbor4.tower2.RemoveFirst()); neighbors.AddLast(neighbor4); } } else { neighbor4.tower3.AddFirst(neighbor4.tower2.RemoveFirst()); neighbors.AddLast(neighbor4); } } //------------------------ if (temp.tower3.Count() != 0) { if (neighbor5.tower1.Count() != 0) { if(neighbor5.tower3.ElementAtOrDefault() < neighbor5.tower1.ElementAtOrDefault()) { neighbor5.tower1.AddFirst(neighbor5.tower3.RemoveFirst()); neighbors.AddLast(neighbor5); } } else { neighbor5.tower1.AddFirst(neighbor5.tower3.RemoveFirst()); neighbors.AddLast(neighbor5); } if (neighbor6.tower2.Count() != 0) { if(neighbor6.tower3.element() < neighbor6.tower2.element()) { neighbor6.tower2.addFirst(neighbor6.tower3.removeFirst()); neighbors.addLast(neighbor6); } } else { neighbor6.tower2.addFirst(neighbor6.tower3.removeFirst()); neighbors.addLast(neighbor6); } } } public override string ToString() { string str; str="tower1"+ tower1.ToString() + " tower2" + tower2.ToString() + " tower3" + tower3.ToString(); return str; } public Sol copy() { Sol So; LinkedList<int> l1= new LinkedList<int>(); LinkedList<int> l2=new LinkedList<int>(); LinkedList<int> l3 = new LinkedList<int>(); for(int i=0;i<=this.tower1.Count() -1;i++) { l1.AddLast(tower1.get(i)); } for(int i=0;i<=this.tower2.size()-1;i++) { l2.addLast(tower2.get(i)); } for(int i=0;i<=this.tower3.size()-1;i++) { l3.addLast(tower3.get(i)); } So = new Sol(l1, l2, l3); return So; } public bool Equals(Sol sol) { if (this.tower1.Equals(sol.tower1) & this.tower2.Equals(sol.tower2) & this.tower3.Equals(sol.tower3)) return true; return false; } public virtual bool containedin(Stack<Sol> vec) { bool found =false; for(int i=0;i<= vec.Count-1;i++) { if(vec.get(i).tower1.Equals(this.tower1) && vec.get(i).tower2.Equals(this.tower2) && vec.get(i).tower3.Equals(this.tower3)) { found=true; break; } } return found; } } }

    Read the article

  • Multiple Windows Forms on one application

    - by Shukhrat Raimov
    I have two windows forms, first is initial and second is invoked when button on the first is pressed. It's two different windows, with different tasks. I programmed for both MVP pattern. But in the Main() I have this: static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); ViewFirst viewFirst = new ViewFirst();//First Form PresenterFirst presenterFirst = new PresenterFirst(viewFirst); Application.Run(viewFirst); } And I Have Second Windows Form: ViewSecond viewSecond = new ViewSecond();//Second Form PresenterSecond presenterSecond = new PresenterSecond(viewSecond); I want to run it in this app as soon as the button on the first is clicked. How could I do this? My button on the first WF is: private void history_button_Click(object sender, EventArgs e) { ViewSecond db = new ViewSecond();//second Form where I have sepparate WF. db.Show(); }

    Read the article

  • The Oracle Graduate Experience...A Graduates Perspective by Angelie Tierney

    - by david.talamelli
    [Note: Angelie has just recently joined Oracle in Australia in our 2011 Graduate Program. Last week I shared my thoughts on our 2011 Graduate Program, this week Angelie took some time to share her thoughts of our Graduate Program. The notes below are Angelie's overview from her experience with us starting with our first contact last year - David Talamelli] How does the 1 year program work? It consists of 3 weeks of training, followed by 2 rotations in 2 different Lines of Business (LoB's). The first rotation goes for 4 months, while your 2nd rotation goes for 7, when you are placed into your final LoB for the program. The interview process: After sorting through the many advertised graduate jobs, submitting so many resumes and studying at the same time, it can all be pretty stressful. Then there is the interview process. David called me on a Sunday afternoon and I spoke to him for about 30 minutes in a mini sort of phone interview. I was worried that working at Oracle would require extensive technical experience, but David stressed that even the less technical, and more business-minded person could, and did, work at Oracle. I was then asked if I would like to attend a group interview in the next weeks, to which I said of course! The first interview was a day long, consisting of a brief introduction, a group interview where we worked on a business plan with a group of other potential graduates and were marked by 3 Oracle employees, on our ability to work together and presentation. After lunch, we then had a short individual interview each, and that was the end of the first round. I received a call a few weeks later, and was asked to come into a second interview, at which I also jumped at the opportunity. This was an interview based purely on your individual abilities and would help to determine which Line of Business you would go to, should you land a graduate position. So how did I cope throughout the interview stages? I believe the best tool to prepare for the interview, was to research Oracle and its culture and to see if I thought I could fit into that. I personally found out about Oracle, its partners as well as competitors and along the way, even found out about their part (or Larry Ellison's specifically) in the Iron Man 2 movie. Armed with some Oracle information and lots of enthusiasm, I approached the Oracle Graduate Interview process. Why did I apply for an Oracle graduate position? I studied a Bachelor of Business/Bachelor of Science in IT, and wanted to be able to use both my degrees, while have the ability to work internationally in the future. Coming straight from university, I wasn't sure exactly what I wanted to do in terms of my career. With the program, you are rotated across various lines of business, to not only expose you to different parts of the business, but to also help you to figure out what you want to achieve out of your career. As a result, I thought Oracle was the perfect fit. So what can an Oracle ANZ Graduate expect? First things first, you can expect to line up for your visitor pass. Really. Next you enter a room full of unknown faces, graduates just like you, and then you realise you're in this with 18 other people, going through the same thing as you. 3 weeks later you leave with many memories, colleagues you can call your friends, and a video of your presentation. Vanessa, the Graduate Manager, will also take lots of photos and keep you (well) fed. Well that's not all you leave with, you are also equipped with a wealth of knowledge and contacts within Oracle, both that will help you throughout your career there. What training is involved? We started our Oracle experience with 3 weeks of training, consisting of employee orientation, extensive product training, presentations on the various lines of business (LoB's), followed by sales and presentation training. While there was potential for an information overload, maybe even death by Powerpoint, we were able to have access to the presentations for future reference, which was very helpful. This period also allowed us to start networking, not only with the graduates, but with the managers who presented to us, as well as through the monthly chinwag, HR celebrations and even with the sharing of tea facilities. We also had a team bonding day when we recorded a "commercial" within groups, and learned how to play an Irish drum. Overall, the training period helped us to learn about Oracle, as well as ourselves, and to prepare us for our transition into our rotations. Where to now? I'm now into my 2nd week of my first graduate rotation. It has been exciting to finally get out into the work environment and utilise that knowledge we gained from training. My manager has been a great mentor, extremely knowledgeable, and it has been good being able to participate in meetings, conference calls and make a contribution towards the business. And while we aren't necessarily working directly with the other graduates, they are still reachable via email, Pidgin and lunch and they are important as a resource and support, after all, they are going through a similar experience to you. While it is only the beginning, there is a lot more to learn and a lot more to experience along the way, especially because, as we learned during training, at Oracle, the only constant is change.

    Read the article

  • MS Environment: How to force link a static library to another using .vsprops, if possible?

    - by msbuildnewbie
    Environment: VS 2008 in Windows. Problem: A static library, say first.lib is not linked to, say second.lib, if first.lib is specified in .vsprops file and none of its functions is referenced in the second.lib. If, however, first.lib is removed from the .vsprops file and placed instead in the appropriate project options dialog(1), it is linked, even if its functions remain unreferenced. (1) Project - Properties - Configuration Properties - Linker - Input. Our solution uses .vsprops exclusively and to somehow be able to specify first.lib in such a file with additional tweaking of some settings would be considered a more elegant solution. Using a dummy function to pull in unused functions of first.lib is not an option. Thanks in advance.

    Read the article

  • WPF Multiline TextBlock LineBreak issues

    - by KMC
    I have the following code txtBlock1.Inlines.Add("This is first paragraph \n This is second paragraph"); then TextBlock would display: This is first paragraph This is second paragraph But, if I have the following (which I though is equivalent); txtBlock1.Inlines.Add("This is first paragraph"); txtBlock1.Inlines.Add("\n"); txtBlock1.Inlines.Add("This is second paragraph"); TextBlock display: This is first paragraph // but second paragraph missing If I separate out the linebreak then the rest of text after the linebreak doesn't show. Why? I have to use run: Run run1 = new Run(); run1.Text = "First Paragraph"; run1.Text += "\n"; run1.Text += "Second Paragraph"; txtBlock1.Inlines.Add(run1); Then it produce the result correctly. Why I cannot add inline text to Textblock and require me to use Run?

    Read the article

  • Randomized experiments in R

    - by gd047
    Here is a simple randomized experiment. In the following code I calculate the p-value under the null hypothesis that two different fertilizers applied to tomato plants have no effect in plants yields. The first random sample (x) comes from plants where a standard fertilizer has been used, while an "improved" one has been used in the plants where the second sample (y) comes from. x <- c(11.4,25.3,29.9,16.5,21.1) y <- c(23.7,26.6,28.5,14.2,17.9,24.3) total <- c(x,y) first <- combn(total,length(x)) second <- apply(first,2,function(x) total[!total %in% x]) dif.treat <- apply(second,2,mean) - apply(first,2,mean) # the first element of dif.treat is the one that I'm interested in (p.value <- length(dif.treat[dif.treat >= dif.treat[1]]) / length(dif.treat)) Do you know of any R function that performs tests like this one?

    Read the article

  • Gnuplot axis scale units

    - by Kami
    I have the following data in a log file: 1270719764.323778250 926 vm-mystery1 1073744528 0 1 1270719764.323815250 926 vm-mystery1 1073746080 0 1 1270719764.323842250 926 vm-mystery1 1075968992 0 1 The first column is a UNIX date that I want to use for my x-axis in a gnuplot graph. My graph looks ugly because the first unit in the x-axis is 1.27072e+09. I would like to have the x-axis looks like the following : x axis [(first row date - first row date) ; (last row date - first row date)] displaying ticks in mili seconds. How to do this ?

    Read the article

  • MySQL limit from descending order

    - by faya
    Hello, Is it available to write a query to use same "LIMIT (from), (count)", but get result in backwards? In example if I have 8 rows in the table and I want to get 5 rows in two steps I would: first step query: select * from table limit 0, 5 first step result: first 5 rows; second step query: select * from table limit 5, 5 second step result: last 3 rows; But I want to get it vice versa. I mean from the first step I want last 3 rows and from the second I want 5 first rows. Thank you for your answer

    Read the article

  • Combine two views into one view

    - by Kevin
    I have two views that I would like to combine into one. The first view shows all items of X where company ID = Y. This is to give preferential sort to the client first, and then everyone else. So I created a second view, all items of X, where company ID != Y. I created it as an Attachment to attach to the first view, but I don't think I got the intended result. How can I combine these views so the first view results are listed first, and then the second view is too, using the same pager, filters, and arguments? Is there any way of achieving this without programming it?

    Read the article

  • Was delegates static by default?

    - by Sri Kumar
    Hello All, I was just trying to understand delegates using the following code. public class delegatesEx { public delegate int Mydelegate(int first, int second); public int add(int first, int second) { return first + second; } public int sub(int first, int second) { return first - second; } } Here is my main method Console.WriteLine("******** Delegates ************"); delegatesEx.Mydelegate myAddDelegates = new delegatesEx.Mydelegate(new delegatesEx().add); int addRes = myAddDelegates(3, 2); Console.WriteLine("Add :" + addRes); delegatesEx.Mydelegate mySubDelegates = new delegatesEx.Mydelegate(new delegatesEx().sub); int subRes = mySubDelegates(3, 2); Console.WriteLine("Sub :" + subRes); I didn't declare delegate to be static but i was able to access it using the Class name. How is it possible?

    Read the article

  • UIView animation

    - by iphonedevnoob
    I have a UIView(first view) on top of which I would like to display another UIView(second view). I display the second view using animation which causes the second view to be displayed for about 3/4 of the iPhone screen. The first view is visible underneath the animated second view. I would like to make changes to the first view as the second view is displayed. Any ideas on how I can achieve this. Right now, the animation completes, the second view is displayed and then I can change the first view. I would like to change the layout of the first screen as the second screen is being displayed. Any help is much appreciated.

    Read the article

  • ScrollView scrolling speed

    - by Psudheer_iph
    hi all, thanx in advance. In my app, i am having 2 scrollviews in view.first scroll is placed bottom and then second Scroll placed. if i scroll either first or second both will scroll depends on finger movements. this is working. But my question is, i want the scrolling speed is different for first scroll and second scroll eg. if first scroll moves 2px speed then second scroll has to move double the speed of first scroll i.e 4px. How can i solve this.

    Read the article

  • Session sharing

    - by GeoXYZ
    Hello, i have a problem with Session sharing... I have a single web application hosted on a server. I created in IIS 2 different domains for the same application (thus each pointing to same physical path). The first domain is used as main interface, and the second domain is used to change settings (kind of like an admin). If the user logs in (login information is stored in session) the first domain, and then goes to the second one, he is also logged in there, which is OK. but when i try to change something in the session (like email address) from the second domain, the data is changed OK but only in the first domain; in the second one i still have the old data... also what i've noticed is that when redirecting from first domain to second domain, every postback control posts back to the first domain even though i am on the second one - this causes encryption errors with the viewstate... If anyone has any ideas, i would appreciate it... Thank you.

    Read the article

  • When did the idea of macros (user-defined code transformation) appear?

    - by Jay
    I have read McCarthy's 1960 paper on LISP and found no reference to anything that's similar to user-defined macros or normal order evaluation. I was wondering when marcos first appeared in programming language history (and also in Lisp history): When was the idea of user-defined code transformation (before interpretation or compilation) first described (theoretically)? What was the first programming language implementation to have Lisp-like macros (by "Lisp-like" I mean "using a readable Turing-complete language to do code-transformation")? (including non-Lisps -- Forth for example is quite old, but I'm not sure if the first Forth implementation already had "IMMEDIATE") What was the first Lisp dialect to have macros? Thank you!

    Read the article

  • Can't find the error in my javascript code

    - by Olivier
    This js program should display the first 100 prime numbers, but instead it crashes each and every time and I can't find the error! Could someone point me towards the best way to debug js code?! Thank you! // initialisation of the array p holding the first 100 prime numbers var p = []; // set the first prime number to 2 p.push(2); // find the first 100 prime numbers and place them in the array p var i = 3; while (p.length < 100) { var prime = true; loop: for (var item in p){ if (i%item === 0){ prime = false; break loop; } } if (prime) p.push(i); i = i + 2; } // display the first 100 prime numbers found var i=1; for (var item in p){ document.writeln(i,item); i++; }

    Read the article

  • jQuery after show() assumes that display:inline is :hidden. Why?

    - by Janis Veinbergs
    With jQuery 1.4.2, :hidden filter is not filtering out elements that were hidden, but i've made then visible by calling show(). Filter assumes it is still hidden. Is this bug or am i missing something? Consider the following code: $("td.ms-authoringcontrols > span[id*='_ParallelApprovers']:hidden:first").css("display") "none" $("td.ms-authoringcontrols > span[id*='_ParallelApprovers']:hidden:first").show() Object $("td.ms-authoringcontrols > span[id*='_ParallelApprovers']:hidden:first").css("display") "inline" // ?? Let me scratch my head... $("td.ms-authoringcontrols > span[id*='_ParallelApprovers']:hidden:first").is(":hidden") true //element with "display:inline", visible in browser, but yet it is hidden Instead of "inline", you would expect "none", because :hidden filter was used. What it does is from an array of objects it selects first hidden element. Each time i call these lines of code, i expect them to select next hidden element (not the one i just showed).

    Read the article

  • Is scala functional programming slower than traditional coding?

    - by Fred Haslam
    In one of my first attempts to create functional code, I ran into a performance issue. I started with a common task - multiply the elements of two arrays and sum up the results: var first:Array[Float] ... var second:Array[Float] ... var sum=0f; for(ix<-0 until first.length) sum += first(ix) * second(ix); Here is how I reformed the work: sum = first.zip(second).map{ case (a,b) => a*b }.reduceLeft(_+_) When I benchmarked the two approaches, the second method takes 40 times as long to complete! Why does the second method take so much longer? How can I reform the work to be both speed efficient and use functional programming style?

    Read the article

  • string reverse without new array

    - by Codeguru
    hi can anybody tell me the error in this? #include<stdio.h> int main() { char a[]="abcdefgh"; int i=0; int n=strlen(a); char *first; char *second; char *c; *first=a[0]; *second=a[7]; for(i=0;i<=n/2;i++) { *c=*first; *first=*second; *second=*c; first++; second--; } for(i=0;i<=7;i++) { printf("%c",a[i]); } }

    Read the article

  • SQL SERVER – Transcript of Learning SQL Server Performance: Indexing Basics – Interview of Vinod Kumar by Pinal Dave

    - by pinaldave
    Recently I just wrote a blog post on about Learning SQL Server Performance: Indexing Basics and I received lots of request that if we can share some insight into the course. Here is 200 seconds interview of Vinod Kumar I took right after completing the course. We have few free codes to watch the course, please your comment at http://facebook.com/SQLAuth and we will few of first ones, we will send the code. There are many people who said they would like to read the transcript of the video. Here I have generated the same. Pinal: Vinod, we recently released this course, SQL Server Indexing. It is about performance tuning. So tell me – how do indexes help performance? Vinod: I think what happens in the industry when it comes to performance is that developers and DBAs look at indexes first.  So that’s the first step for any performance tuning exercise, indexing is one of the most critical aspects and it is important to learn it the right way. Pinal: Correct. So what you mean to say is that if you know indexing you can pretty much tune any server and query. Vinod: So I might contradict my false statement now. Indexing is usually a stepping stone but it does not lead you to the end. But it’s good to start with indexing and there are lots of nuances to indexing that you need to understand, like how SQL uses indexing and how performance can improve because of the strategies that you have made. Pinal: But now I’m confused. First you said indexes are good, and then you said that indexes can degrade your performance.  So what is this course about?  I mean how does this course really make an impact? Vinod: Ok -so from the course perspective, what we are trying to do is give you a capsule which gives you a good start. Every journey needs a beginning, you need that first step.  This course is that first step in understanding. This is the most basic, fundamental course that we have tried to attack. This is the fundamentals of indexing, some of the key things that you must know about indexing.   Some of the basics of indexing are lesser known and so I think this course is geared towards each and every one of you out there who wants to understand little bit more about indexing. Pinal: So what I understand is that if I enrolled in this course I will have a minimum understanding about indexing when dealing with performance tuning.  Right? Vinod: Exactly. In this course is we have tried to give you a nice summary. We are talking about clustered indexing, non clustered indexing, too many indexes, too few indexes, over indexing, under indexing, duplicate indexing, columns tune indexing, with SQL Server 2012. There’s lot’s to learn. Pinal: You can see the URL [http://bit.ly/sql-index] of the course on the screen. Go ahead, attend, and let us know what you think about it. Thank you. Vinod: Thank you. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology, Video

    Read the article

  • Stretch in multiple components using af:popup, af:region, af:panelTabbed

    - by Arvinder Singh
    Case study: I have a pop-up(dialogue) that contains a region(separate taskflow) showing a tab. The contents of this tab is in a region having a separate taskflow. The jsff page of this taskflow contains a panelSplitter which in turn contains a table. In short the components are : pop-up(dialogue) --> region(separate taskflow) --> tab --> region(separate taskflow) --> panelSplitter --> table At times the tab is not displayed with 100% width or the table in panelSplitter is not 100% visible or the splitter is not visible. Maintaining the stretch for all the components is difficult......not any more!!! Below is the solution that you can make use of in many similar scenarios. I am mentioning the major code snippets affecting the stretch and alignment. pop-up: <af:popup> <af:dialog id="d2" type="none" title="" inlineStyle="width:1200px"> <af:region value="#{bindings.PriceChangePopupFlow1.regionModel}" id="r1"/> </af:dialog> The above region is a jsff containing multiple tabs. I am showing code for a single tab. I kept the tab in a panelStretchLayout. <af:panelStretchLayout id="psl1" topHeight="300px" styleClass="AFStretchWidth"> <af:panelTabbed id="pt1"> <af:showDetailItem text="PO Details" id="sdi1" stretchChildren="first" > <af:region value="#{bindings.PriceChangePurchaseOrderFlow1.regionModel}" id="r1" binding="# {pageFlowScope.priceChangePopupBean.poDetailsRegion}" /> This "region" displays a .jsff containing a table in a panelSplitter. <af:panelSplitter id="ps1"  orientation="horizontal" splitterPosition="700"> <f:facet name="first"> <af:panelHeader text="PurchaseOrder" id="ph1"> <af:table id="md1" rows="#{bindings.PurchaseOrderVO.rangeSize}" That's it!!! We're done... Note the stretchChildren="first" attribute in the af:showDetailItem. That does the trick for us. Oracle docs say the following about stretchChildren :  Valid Values: none, first The stretching behavior for children. Acceptable values include: "none": does not attempt to stretch any children (the default value and the value you need to use if you have more than a single child; also the value you need to use if the child does not support being stretched) "first": stretches the first child (not to be used if you have multiple children as such usage will produce unreliable results; also not to be used if the child does not support being stretched)

    Read the article

  • JDK 7u25: Solutions to Issues caused by changes to Runtime.exec

    - by Devika Gollapudi
    The following examples were prepared by Java engineering for the benefit of Java developers who may have faced issues with Runtime.exec on the Windows platform. Background In JDK 7u21, the decoding of command strings specified to Runtime.exec(String), Runtime.exec(String,String[]) and Runtime.exec(String,String[],File) methods, has been made more strict. See JDK 7u21 Release Notes for more information. This caused several issues for applications. The following section describes some of the problems faced by developers and their solutions. Note: In JDK 7u25, the system property jdk.lang.Process.allowAmbigousCommands can be used to relax the checking process and helps as a workaround for some applications that cannot be changed. The workaround is only effective for applications that are run without a SecurityManager. See JDK 7u25 Release Notes for more information. Note: To understand the details of the Windows API CreateProcess call, see: http://msdn.microsoft.com/en-us/library/windows/desktop/ms682425%28v=vs.85%29.aspx There are two forms of Runtime.exec calls: with the command as string: "Runtime.exec(String command[, ...])" with the command as string array: "Runtime.exec(String[] cmdarray [, ...] )" The issues described in this section relate to the first form of call. With the first call form, developers expect the command to be passed "as is" to Windows where the command needs be split into its executable name and arguments parts first. But, in accordance with Java API, the command argument is split into executable name and arguments by spaces. Problem 1: "The file path for the command includes spaces" In the call: Runtime.getRuntime().exec("c:\\Program Files\\do.exe") the argument is split by spaces to an array of strings as: c:\\Program, Files\\do.exe The first element of parsed array is interpreted as the executable name, verified by SecurityManager (if present) and surrounded by quotations to avoid ambiguity in executable path. This results in the wrong command: "c:\\Program" "Files\\do.exe" which will fail. Solution: Use the ProcessBuilder class, or the Runtime.exec(String[] cmdarray [, ...] ) call, or quote the executable path. Where it is not possible to change the application code and where a SecurityManager is not used, the Java property jdk.lang.Process.allowAmbigousCommands could be used by setting its value to "true" from the command line: -Djdk.lang.Process.allowAmbigousCommands=true This will relax the checking process to allow ambiguous input. Examples: new ProcessBuilder("c:\\Program Files\\do.exe").start() Runtime.getRuntime().exec(new String[]{"c:\\Program Files\\do.exe"}) Runtime.getRuntime().exec("\"c:\\Program Files\\do.exe\"") Problem 2: "Shell command/.bat/.cmd IO redirection" The following implicit cmd.exe calls: Runtime.getRuntime().exec("dir temp.txt") new ProcessBuilder("foo.bat", "", "temp.txt").start() Runtime.getRuntime().exec(new String[]{"foo.cmd", "", "temp.txt"}) lead to the wrong command: "XXXX" "" temp.txt Solution: To specify the command correctly, use the following options: Runtime.getRuntime().exec("cmd /C \"dir temp.txt\"") new ProcessBuilder("cmd", "/C", "foo.bat temp.txt").start() Runtime.getRuntime().exec(new String[]{"cmd", "/C", "foo.cmd temp.txt"}) or Process p = new ProcessBuilder("cmd", "/C" "XXX").redirectOutput(new File("temp.txt")).start(); Problem 3: "Group execution of shell command and/or .bat/.cmd files" Due to enforced verification procedure, arguments in the following calls create the wrong commands.: Runtime.getRuntime().exec("first.bat && second.bat") new ProcessBuilder("dir", "&&", "second.bat").start() Runtime.getRuntime().exec(new String[]{"dir", "|", "more"}) Solution: To specify the command correctly, use the following options: Runtime.exec("cmd /C \"first.bat && second.bat\"") new ProcessBuilder("cmd", "/C", "dir && second.bat").start() Runtime.exec(new String[]{"cmd", "/C", "dir | more"}) The same scenario also works for the "&", "||", "^" operators of the cmd.exe shell. Problem 4: ".bat/.cmd with special DOS chars in quoted params” Due to enforced verification, arguments in the following calls will cause exceptions to be thrown.: Runtime.getRuntime().exec("log.bat \"error new ProcessBuilder("log.bat", "error Runtime.getRuntime().exec(new String[]{"log.bat", "error Solution: To specify the command correctly, use the following options: Runtime.getRuntime().exec("cmd /C log.bat \"error new ProcessBuilder("cmd", "/C", "log.bat", "error Runtime.getRuntime().exec(new String[]{"cmd", "/C", "log.bat", "error Examples: Complicated redirection for shell construction: cmd /c dir /b C:\ "my lovely spaces.txt" becomes Runtime.getRuntime().exec(new String[]{"cmd", "/C", "dir \b \"my lovely spaces.txt\"" }); The Golden Rule: In most cases, cmd.exe has two arguments: "/C" and the command for interpretation.

    Read the article

  • Kinect losing tracked players with Beta2 SDK

    - by Eric B
    So i'm creating a game using the Beta2 SDK for Kinect. The issue i am having is that in the middle of gameplay if another person enters the Kinects FOV it stops tracking the player and will not track anyone else for several minutes. Same deal if the player leaves the FOV and reenters it. Here is what im using to detect players. void nui_SkeletonFrameReady(object sender, SkeletonFrameReadyEventArgs e) { int playersAlive = 0; // reset lists skeletons = new Dictionary<int, SkeletonData>(); //create a new list for skeletons menuSkeleton = new List<SkeletonData>(); initialPlayers = new Dictionary<float, SkeletonData>(); //create a new list for initialPlayers foreach (SkeletonData s in e.SkeletonFrame.Skeletons) //for each skeleton the kinect has detected { if (s.TrackingState == SkeletonTrackingState.Tracked) // players found { menuSkeleton.Add(s); if (initialized) // after initialization { skeletons.Add(s.TrackingID, s); } else // before initialization initialPlayers.Add(s.Joints[JointID.ShoulderCenter].Position.X, s); //if we are not initialized then add this player to the inital player list. playersAlive++; } } if (playersAlive == TOTAL_PLAYERS_ALLOWED) // If there is one player { if (!inMiniGame) // Before the game starts gameStart = DateTime.Now; // Reset initialization timer if (!initialized) // Before initialization // NOTE TO SELF I TOOK OUT && inMenu { InitializePlayers(); if (DateTime.Now.Subtract(gameStart).TotalMilliseconds > INITIALIZATION_WAIT_TIME) { initialized = true; // initialize timers from fixed starting time if (inMiniGame) //if the game has started { gamePause = gameStart; //TODO ERIC: Initialize any Timers Here } } } } } /// <summary> /// this function initializes the players adding them to a list /// and making one of the players the menu controller, for LIM we will need to change the code so that the /// game only recognizes and supports one player at a time /// variable names will need to be change as well. /// </summary> private void InitializePlayers() { List<float> initialPos = new List<float>(); // used to track starting positions players = new Dictionary<int, Player>(); foreach (float pos in initialPlayers.Keys) { initialPos.Add(pos); //add position of each inital player to list } float first = initialPos[0]; // left player first, right second Player player = new Player(initialPlayers[first].TrackingID, true); player.PlayerNumber = PLAYER_ONE; player.Skeleton = initialPlayers[first]; player.Specifics = new PlayerSpecifics(player.PlayerNumber); player.Specifics.PauseTimer = gameStart; players.Add(initialPlayers[first].TrackingID, player); menuController = initialPlayers[first].TrackingID; //menu controller is player 1 } This is a one player game. Also when the game starts Initialize is set to false, and gets set to true when i go from the games menu into the gameplay. So can anyone see any issues with this code block that would cause the kinect to lose players as they enter/exit the FOV? and not re-track them? Thank you for any help.

    Read the article

  • Why is x=x++ undefined?

    - by ugoren
    It's undefined because the it modifies x twice between sequence points. The standard says it's undefined, therefore it's undefined. That much I know. But why? My understanding is that forbidding this allows compilers to optimize better. This could have made sense when C was invented, but now seems like a weak argument. If we were to reinvent C today, would we do it this way, or can it be done better? Or maybe there's a deeper problem, that makes it hard to define consistent rules for such expressions, so it's best to forbid them? So suppose we were to reinvent C today. I'd like to suggest simple rules for expressions such as x=x++, which seem to me to work better than the existing rules. I'd like to get your opinion on the suggested rules compared to the existing ones, or other suggestions. Suggested Rules: Between sequence points, order of evaluation is unspecified. Side effects take place immediately. There's no undefined behavior involved. Expressions evaluate to this value or that, but surely won't format your hard disk (strangely, I've never seen an implementation where x=x++ formats the hard disk). Example Expressions x=x++ - Well defined, doesn't change x. First, x is incremented (immediately when x++ is evaluated), then it's old value is stored in x. x++ + ++x - Increments x twice, evaluates to 2*x+2. Though either side may be evaluated first, the result is either x + (x+2) (left side first) or (x+1) + (x+1) (right side first). x = x + (x=3) - Unspecified, x set to either x+3 or 6. If the right side is evaluated first, it's x+3. It's also possible that x=3 is evaluated first, so it's 3+3. In either case, the x=3 assignment happens immediately when x=3 is evaluated, so the value stored is overwritten by the other assignment. x+=(x=3) - Well defined, sets x to 6. You could argue that this is just shorthand for the expression above. But I'd say that += must be executed after x=3, and not in two parts (read x, evaluate x=3, add and store new value). What's the Advantage? Some comments raised this good point. It's not that I'm after the pleasure of using x=x++ in my code. It's a strange and misleading expression. What I want is to be able to understand complicated expressions. Normally, a complicated expression is no more than the sum of its parts. If you understand the parts and the operators combining them, you can understand the whole. C's current behavior seems to deviate from this principle. One assignment plus another assignment suddenly doesn't make two assignments. Today, when I look at x=x++, I can't say what it does. With my suggested rules, I can, by simply examining its components and their relations.

    Read the article

  • SQL Server: Writing CASE expressions properly when NULLs are involved

    - by Mladen Prajdic
    We’ve all written a CASE expression (yes, it’s an expression and not a statement) or two every now and then. But did you know there are actually 2 formats you can write the CASE expression in? This actually bit me when I was trying to add some new functionality to an old stored procedure. In some rare cases the stored procedure just didn’t work correctly. After a quick look it turned out to be a CASE expression problem when dealing with NULLS. In the first format we make simple “equals to” comparisons to a value: SELECT CASE <value> WHEN <equals this value> THEN <return this> WHEN <equals this value> THEN <return this> -- ... more WHEN's here ELSE <return this> END Second format is much more flexible since it allows for complex conditions. USE THIS ONE! SELECT CASE WHEN <value> <compared to> <value> THEN <return this> WHEN <value> <compared to> <value> THEN <return this> -- ... more WHEN's here ELSE <return this> END Now that we know both formats and you know which to use (the second one if that hasn’t been clear enough) here’s an example how the first format WILL make your evaluation logic WRONG. Run the following code for different values of @i. Just comment out any 2 out of 3 “SELECT @i =” statements. DECLARE @i INTSELECT  @i = -1 -- first resultSELECT  @i = 55 -- second resultSELECT  @i = NULL -- third resultSELECT @i AS OriginalValue, -- first CASE format. DON'T USE THIS! CASE @i WHEN -1 THEN '-1' WHEN NULL THEN 'We have a NULL!' ELSE 'We landed in ELSE' END AS DontUseThisCaseFormatValue, -- second CASE format. USE THIS! CASE WHEN @i = -1 THEN '-1' WHEN @i IS NULL THEN 'We have a NULL!' ELSE 'We landed in ELSE' END AS UseThisCaseFormatValue When the value of @i is –1 everything works as expected, since both formats go into the –1 WHEN branch. When the value of @i is 55 everything again works as expected, since both formats go into the ELSE branch. When the value of @i is NULL the problems become evident. The first format doesn’t go into the WHEN NULL branch because it makes an equality comparison between two NULLs. Because a NULL is an unknown value: NULL = NULL is false. That is why the first format goes into the ELSE Branch but the second format correctly handles the proper IS NULL comparison.   Please use the second more explicit format. Your future self will be very grateful to you when he doesn’t have to discover these kinds of bugs.

    Read the article

  • Number nested ordered lists in HTML

    - by John
    Hi I have a nested ordered list. <ol> <li>first</li> <li>second <ol> <li>second nested first element</li> <li>second nested secondelement</li> <li>second nested thirdelement</li> </ol> </li> <li>third</li> <li>fourth</li> </ol> Currently the nested elements start back from 1 again, e.g. first second second nested first element second nested second element second nested third element third fourth What I want is for the second element to be numbered like this: first second 2.1. second nested first element 2.2. second nested second element 2.3. second nested third element third fourth Is there a way of doing this? Thanks

    Read the article

< Previous Page | 84 85 86 87 88 89 90 91 92 93 94 95  | Next Page >