Search Results

Search found 29111 results on 1165 pages for 'program structure'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 123/1165 | < Previous Page | 119 120 121 122 123 124 125 126 127 128 129 130  | Next Page >

  • Trying to not need two separate solutions for x86 and x64 program.

    - by Sean Anderson
    Hi all, I have a program which needs to function in both an x86 and an x64 environment. It is using Oracle's ODBC drivers. I have a reference to Oracle.DataAccess.DLL. This DLL is different depending on whether the system is x64 or x86, though. Currently, I have two separate solutions and I am maintaining the code on both. This is atrocious. I was wondering what the proper solution is? I have my platform set to "Any CPU." and it is my understanding that VS should compile the DLL to an intermediary language such that it should not matter if I use the x86 or x64 version. Yet, if I attempt to use the x64 DLL I receive the error "Could not load file or assembly 'Oracle.DataAccess, Version=2.102.3.2, Culture=neutral, PublicKeyToken=89b483f429c47342' or one of its dependencies. An attempt was made to load a program with an incorrect format." I am running on a 32 bit machine, so the error message makes sense, but it leaves me wondering how I am supposed to efficiently develop this program when it needs to work on x64. Thanks.

    Read the article

  • Write a C++ program to encrypt and decrypt certain codes.

    - by Amber
    Step 1: Write a function int GetText(char[],int); which fills a character array from a requested file. That is, the function should prompt the user to input the filename, and then read up to the number of characters given as the second argument, terminating when the number has been reached or when the end of file is encountered. The file should then be closed. The number of characters placed in the array is then returned as the value of the function. Every character in the file should be transferred to the array. Whitespace should not be removed. When testing, assume that no more than 5000 characters will be read. The function should be placed in a file called coding.cpp while the main will be in ass5.cpp. To enable the prototypes to be accessible, the file coding.h contains the prototypes for all the functions that are to be written in coding.cpp for this assignment. (You may write other functions. If they are called from any of the functions in coding.h, they must appear in coding.cpp where their prototypes should also appear. Do not alter coding.h. Any other functions written for this assignment should be placed, along with their prototypes, with the main function.) Step 2: Write a function int SimplifyText(char[],int); which simplifies the text in the first argument, an array containing the number of characters as given in the second argument, by converting all alphabetic characters to lower case, removing all non-alpha characters, and replacing multiple whitespace by one blank. Any leading whitespace at the beginning of the array should be removed completely. The resulting number of characters should be returned as the value of the function. Note that another array cannot appear in the function (as the file does not contain one). For example, if the array contained the 29 characters "The 39 Steps" by John Buchan (with the " appearing in the array), the simplified text would be the steps by john buchan of length 24. The array should not contain a null character at the end. Step 3: Using the file test.txt, test your program so far. You will need to write a function void PrintText(const char[],int,int); that prints out the contents of the array, whose length is the second argument, breaking the lines to exactly the number of characters in the third argument. Be warned that, if the array contains newlines (as it would when read from a file), lines will be broken earlier than the specified length. Step 4: Write a function void Caesar(const char[],int,char[],int); which takes the first argument array, with length given by the second argument and codes it into the third argument array, using the shift given in the fourth argument. The shift must be performed cyclicly and must also be able to handle negative shifts. Shifts exceeding 26 can be reduced by modulo arithmetic. (Is C++'s modulo operations on negative numbers a problem here?) Demonstrate that the test file, as simplified, can be coded and decoded using a given shift by listing the original input text, the simplified text (indicating the new length), the coded text and finally the decoded text. Step 5: The permutation cypher does not limit the character substitution to just a shift. In fact, each of the 26 characters is coded to one of the others in an arbitrary way. So, for example, a might become f, b become q, c become d, but a letter never remains the same. How the letters are rearranged can be specified using a seed to the random number generator. The code can then be decoded, if the decoder has the same random number generator and knows the seed. Write the function void Permute(const char[],int,char[],unsigned long); with the same first three arguments as Caesar above, with the fourth argument being the seed. The function will have to make up a permutation table as follows: To find what a is coded as, generate a random number from 1 to 25. Add that to a to get the coded letter. Mark that letter as used. For b, generate 1 to 24, then step that many letters after b, ignoring the used letter if encountered. For c, generate 1 to 23, ignoring a or b's codes if encountered. Wrap around at z. Here's an example, for only the 6 letters a, b, c, d, e, f. For the letter a, generate, from 1-5, a 2. Then a - c. c is marked as used. For the letter b, generate, from 1-4, a 3. So count 3 from b, skipping c (since it is marked as used) yielding the coding of b - f. Mark f as used. For c, generate, from 1-3, a 3. So count 3 from c, skipping f, giving a. Note the wrap at the last letter back to the first. And so on, yielding a - c b - f c - a d - b (it got a 2) e - d f - e Thus, for a given seed, a translation table is required. To decode a piece of text, we need the table generated to be re-arranged so that the right hand column is in order. In fact you can just store the table in the reverse way (e.g., if a gets encoded to c, put a opposite c is the table). Write a function called void DePermute(const char[],int,char[], unsigned long); to reverse the permutation cypher. Again, test your functions using the test file. At this point, any main program used to test these functions will not be required as part of the assignment. The remainder of the assignment uses some of these functions, and needs its own main function. When submitted, all the above functions will be tested by the marker's own main function. Step 6: If the seed number is unknown, decoding is difficult. Write a main program which: (i) reads in a piece of text using GetText; (ii) simplifies the text using SimplifyText; (iii) prints the text using PrintText; (iv) requests two letters to swap. If we think 'a' in the text should be 'q' we would type aq as input. The text would be modified by swapping the a's and q's, and the text reprinted. Repeat this last step until the user considers the text is decoded, when the input of the same letter twice (requesting a letter to be swapped with itself) terminates the program. Step 7: If we have a large enough sample of coded text, we can use knowledge of English to aid in finding the permutation. The first clue is in the frequency of occurrence of each letter. Write a function void LetterFreq(const char[],int,freq[]); which takes the piece of text given as the first two arguments (same as above) and returns in the 26 long array of structs (the third argument), the table of the frequency of the 26 letters. This frequency table should be in decreasing order of popularity. A simple Selection Sort will suffice. (This will be described in lectures.) When printed, this summary would look something like v x r s z j p t n c l h u o i b w d g e a q y k f m 168106 68 66 59 54 48 45 44 35 26 24 22 20 20 20 17 13 12 12 4 4 1 0 0 0 The formatting will require the use of input/output manipulators. See the header file for the definition of the struct called freq. Modify the program so that, before each swap is requested, the current frequency of the letters is printed. This does not require further calls to LetterFreq, however. You may use the traditional order of regular letter frequencies (E T A I O N S H R D L U) as a guide when deciding what characters to exchange. Step 8: The decoding process can be made more difficult if blank is also coded. That is, consider the alphabet to be 27 letters. Rewrite LetterFreq and your main program to handle blank as another character to code. In the above frequency order, space usually comes first.

    Read the article

  • Can you get any program in Linux to print a stack trace if it segfaults?

    - by Neil
    If I run a program from the shell, and it segfaults: $ buggy_program Segmentation fault It will tell me, however, is there a way to get programs to print a backtrace, perhaps by running something like this: $ print_backtrace_if_segfault buggy_program Segfault in main.c:35 (rest of the backtrace) I'd also rather not use strace or ltrace for that kind of information, as they'll print either way...

    Read the article

  • Program repeats each time a character is scanned .. How to stop it ?

    - by ZaZu
    Hello there, I have a program that has this code : #include<stdio.h> main(){ int input; char g; do{ printf("Choose a numeric value"); printf(">"); scanf("\n%c",&input); g=input-'0'; }while((g>=-16 && g<=-1)||(g>=10 && g<=42)||(g>=43 && g<=79)); } It basically uses ASCII manipulation to allow the program to accept numbers only .. '0' is given the value 48 by default...the ASCII value - 48 gives a ranges of numbers above (in the while statement) Anyway, whenever a user inputs numbers AND alphabets, such as : abr39293afakvmienb23 The program ignores : a,b,r .. But takes '3' as the first input. For a b and r, the code under the do loop repeats. So for the above example, I get : Choose a numeric value >Choose a numeric value> Choose a numeric value >3 Is there a way I can stop this ??? I tried using \n%c to scan the character and account for whitespace, but that didnt work :( Please help thank you very much !

    Read the article

  • Would anybody mind taking a look at my XML structure?

    - by Bill H
    I am relatively new to this but I was hoping somebody could offer up a good critique of this XML structure I put together. I am not looking for anything in depth but rather if somebody notices anything inherently wrong with the structure (or any tips to make it better) I'd greatly appreciate it. We have a large amount of products that we wholesale out and our customers were looking for a data feed to incorporate our products into their websites. <product modified=""> <id></id> <title></title> <description></description> <upc></upc> <quantity></quantity> <images> <image width="" height=""></image> <image width="" height=""></image> <image width="" height=""></image> </images> <category> <name></name> <subcategory></subcategory> </category> <sale expiration="">yes</sale> <msrp></msrp> <cube></cube> <weight></weight> <pricing> <tier> <pack><pack> <price></price> </tier> <tier> <pack><pack> <price></price> </tier> <tier> <pack><pack> <price></price> </tier> </pricing> </product> We sell in 3 different pack sizes hence the pricing node.

    Read the article

  • java bubblesort with acm dialog

    - by qzar
    Hi, the program gives following exception: Exception in thread "main" java.lang.NullPointerException at myclasses.BubbleSort.run(BubbleSort.java:42) at acm.program.Program.runHook(Program.java:1519) at acm.program.Program.startRun(Program.java:1508) at acm.program.Program.start(Program.java:729) at myclasses.BubbleSort.main(BubbleSort.java:49) what is wrong? thank you very much! package myclasses; import acm.program.DialogProgram; public class BubbleSort extends DialogProgram { int[] array; public int[] getArray() { return array; } public void setArray(int[] array) { this.array = array; } void swap(int firstPos, int secondPos) { int temp = array[firstPos]; array[firstPos] = array[secondPos]; array[secondPos] = temp; } public void bubblesort() { int i, j, k; for (i = 1; i < array.length; i++) { j = i; k = array[i]; while (j > 0 && array[j - 1] > k) { array[j] = array[j - 1]; --j; } array[j] = k; } } public void run() { BubbleSort a = new BubbleSort(); a.setArray(new int[] {1, 3, 5, 7, 6, 2}); a.bubblesort(); StringBuffer sb = new StringBuffer(a.array.length * 2); for (int i = 0; i < getArray().length; i++) sb.append(getArray()[i]).append(" "); println(sb); } public static void main(String[] args) { new BubbleSort().start(args); } }

    Read the article

  • What is the best practice for including third party jar files in a Java program?

    - by ZoFreX
    I have a program that needs several third-party libraries, and at the moment it is packaged like so: zerobot.jar (my file) libs/pircbot.jar libs/mysql-connector-java-5.1.10-bin.jar libs/c3p0-0.9.1.2.jar As far as I know the "best" way to handle third-party libs is to put them on the classpath in the manifest of my jar file, which will work cross-platform, won't slow down launch (which bundling them might) and doesn't run into legal issues (which repackaging might). The problem is for users who supply the third party libraries themselves (example use case, upgrading them to fix a bug). Two of the libraries have the version number in the file, which adds hassle. My current solution is that my program has a bootstrapping process which makes a new classloader and instantiates the program proper using it. This custom classloader adds all .jar files in lib/ to its classpath. My current way works fine, but I now have two custom classloaders in my application and a recent change to the code has caused issues that are difficult to debug, so if there is a better way I'd like to remove this complexity. It also seems like over-engineering for what I'm sure is a very common situation. So my question is, how should I be doing this?

    Read the article

  • How to modify Keyboard interrupt (under Windows XP) from a C++ Program ?

    - by rockr90
    Hi everyone ! We have been given a little project (As part of my OS course) to make a Windows program that modifies keyboard input, so that it transforms any lowercase character entered into an uppercase one (without using caps-lock) ! so when you type on the keyboard you'll see what you're typing transformed into uppercase ! I have done this quite easily using Turbo C by calling geninterrupt() and using variables _AH, _AL, i had to read a character using: _AH = 0x07; // Reading a character without echo geninterrupt(0x21); // Dos interrupt Then to transform it into an Upercase letter i have to mask the 5th bit by using: _AL = _AL & 0xDF; // Masking the entered character with 11011111 and then i will display the character using any output routine. Now, this solution will only work under old C DOS compilers. But what we intend to do is to make a close or similar solution to this by using any modern C/C++ compiler under Windows XP ! What i have first thought of is modifying the Keyboard ISR so that it masks the fifth bit of any entered character to turn it uppercase ! But i do not know how exactly to do this. Second, I wanted to create a Win32 console program to either do the same solution (but to no avail) or make a windows-compatible solution, still i do not know which functions to use ! Third I thought to make a windows program that modifies the ISR directly to suit my needs ! and i'm still looking for how to do this ! So please, If you could help me out on this, I would greatly appreciate it ! Thank you in advance ! (I'm using Windows XP on intel X86 with mingw-GCC compiler.)

    Read the article

  • What database table structure should I use for versions, codebases, deployables?

    - by Zac Thompson
    I'm having doubts about my table structure, and I wonder if there is a better approach. I've got a little database for version control repositories (e.g. SVN), the packages (e.g. Linux RPMs) built therefrom, and the versions (e.g. 1.2.3-4) thereof. A given repository might produce no packages, or several, but if there are more than one for a given repository then a particular version for that repository will indicate a single "tag" of the codebase. A particular version "string" might be used to tag a version of the source code in more than one repository, but there may be no relationship between "1.0" for two different repos. So if packages P and Q both come from repo R, then P 1.0 and Q 1.0 are both built from the 1.0 tag of repo R. But if package X comes from repo Y, then X 1.0 has no relationship to P 1.0. In my (simplified) model, I have the following tables (the x_id columns are auto-incrementing surrogate keys; you can pretend I'm using a different primary key if you wish, it's not really important): repository - repository_id - repository_name (unique) ... version - version_id - version_string (unique for a particular repository) - repository_id ... package - package_id - package_name (unique) - repository_id ... This makes it easy for me to see, for example, what are valid versions of a given package: I can join with the version table using the repository_id. However, suppose I would like to add some information to this database, e.g., to indicate which package versions have been approved for release. I certainly need a new table: package_version - version_id - package_id - package_version_released ... Again, the nature of the keys that I use are not really important to my problem, and you can imagine that the data column is "promotion_level" or something if that helps. My doubts arise when I realize that there's really a very close relationship between the version_id and the package_id in my new table ... they must share the same repository_id. Only a small subset of package/version combinations are valid. So I should have some kind of constraint on those columns, enforcing that ... ... I don't know, it just feels off, somehow. Like I'm including somehow more information than I really need? I don't know how to explain my hesitance here. I can't figure out which (if any) normal form I'm violating, but I also can't find an example of a schema with this sort of structure ... not being a DBA by profession I'm not sure where to look. So I'm asking: am I just being overly sensitive?

    Read the article

  • Is there any workaround for making a structure member somehow 'private' in C ?

    - by nomemory
    I am developing a simple library in C, for my own + some friends personal use. I am currently having a C structure with some members that should be somehow hidden from the rest of the application, as their use is only internal. Modifying by accident one of this members will probably make the library 'go wild'. Is there any 'workaround' to hide those members so that they can't be accessible ?

    Read the article

  • BASIC Menu-driven program repeates twice after successful completion of first task.

    - by Zazu
    Hello, Im using Plato3 to write C programs. Im creating a menu-driven program but want to test out the basic concept of getting it to work #include<stdio.h> #include<ctype.h> int function1(); main(){ char s; do{ puts("\n choose the following"); puts("(P)rint\n"); puts("(Q)uit\n"); scanf("%c",&s); s=toupper(s); switch (s){ case 'P' : function1(); break; case 'Q' : return -1; break; } }while (function1()==0); } int function1(){ printf("Hello World"); return 0; } The problem is that once function1() returns the value 0, the whole program is echoed ... why ? Example : Running the program gives this : Hello WorldHellow World choose the following (P)rint (Q)uit Hello World choose the following (P)rint (Q)uit -- Any idea why ? Please help, thanks !!!!

    Read the article

  • How can I find out if a given program is 64 or 32 bit version?

    - by maaartinus
    How can I find out if a given program is 64 or 32 bit version? I can't to do it by simply looking at where it's installed, since some programs need no installer and may be put anywhere. Here, no process explorer will help me, since the application refuses to start. Reason why I need it: My new eclipse installation fails to load "jvm.dll" just like here. I'd bet I'm using 64-bit versions of both eclipse and JVM, but I'm slowly getting unsure....

    Read the article

  • how do I get the program to Know which annotation is selected and be able to access properties of it

    - by kevin Mendoza
    So far my program can display a database of custom annotation views. Eventually I want my program to be able to display extra information after a button on the annotation bubble is clicked. Each element in the database has a unique entry Number, so I thought it would be a good idea to add this entry number as a property of the custom annotation. The problem I am having is that after the button is clicked and the program switches to a new view I am unable to retrieve the entry number of the annotation I selected. Below is the code that assigns the entry Number property to the annotation: for (id mine in mines) { workingCoordinate.latitude = [[mine latitudeInitial] doubleValue]; workingCoordinate.longitude = [[mine longitudeInitial] doubleValue]; iProspectAnnotation *tempMine = [[iProspectAnnotation alloc] initWithCoordinate:workingCoordinate]; [tempMine setTitle:[mine mineName]]; [tempMine setAnnotationEntryNumber:[mine entryNumber]]; } [mines dealloc]; When the button on an annotation is selected, this is the code that initializes the new view: - (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control { mineInformationController *controller = [[mineInformationController alloc] initWithNibName:@"mineInformationController" bundle:nil]; controller.modalTransitionStyle = UIModalTransitionStyleCrossDissolve; [self presentModalViewController:controller animated:YES]; [controller release]; } and lastly is my attempt at retrieving the entryNumber property from the new view so that I can compare it to the mines database and retrieve more information on the array element. iProspectFresno_LiteAppDelegate *appDelegate = (iProspectFresno_LiteAppDelegate *)[[UIApplication sharedApplication] delegate]; NSMutableArray* mines = [[NSMutableArray alloc] initWithArray:(NSMutableArray *)appDelegate.mines]; for(id mine in mines) { if ([[mine entryNumber] isEqualToNumber: /*the entry Number of the selected annotation*/]) { /* display the information in the mine object */ } } So how do I access this entry number property in this new view controller?

    Read the article

  • How do I get the "bucket id" that winqual uses if I have a minidump file or exception structure? (Windows c++)

    - by Tim
    There are a few related questions on SO - but have not found the answer - I would like to generate a "signature"/bucket id to report a minidump/crash back to our issue tracking system. Since MS already does this with "bucket ids" I figured I could just re-use their bucket/signature generation. Can I get that ID from either a top level filter or the _EXCEPTION_POINTERS object I have inside the filter or the _MINIDUMP_EXCEPTION_INFORMATION structure or from the minidump itself? This is a C++ application.

    Read the article

  • Project Euler #18 - how to brute force all possible paths in tree-like structure using Python?

    - by euler user
    Am trying to learn Python the Atlantic way and am stuck on Project Euler #18. All of the stuff I can find on the web (and there's a LOT more googling that happened beyond that) is some variation on 'well you COULD brute force it, but here's a more elegant solution'... I get it, I totally do. There are really neat solutions out there, and I look forward to the day where the phrase 'acyclic graph' conjures up something more than a hazy, 1 megapixel resolution in my head. But I need to walk before I run here, see the state, and toy around with the brute force answer. So, question: how do I generate (enumerate?) all valid paths for the triangle in Project Euler #18 and store them in an appropriate python data structure? (A list of lists is my initial inclination?). I don't want the answer - I want to know how to brute force all the paths and store them into a data structure. Here's what I've got. I'm definitely looping over the data set wrong. The desired behavior would be to go 'depth first(?)' rather than just looping over each row ineffectually.. I read ch. 3 of Norvig's book but couldn't translate the psuedo-code. Tried reading over the AIMA python library for ch. 3 but it makes too many leaps. triangle = [ [75], [95, 64], [17, 47, 82], [18, 35, 87, 10], [20, 4, 82, 47, 65], [19, 1, 23, 75, 3, 34], [88, 2, 77, 73, 7, 63, 67], [99, 65, 4, 28, 6, 16, 70, 92], [41, 41, 26, 56, 83, 40, 80, 70, 33], [41, 48, 72, 33, 47, 32, 37, 16, 94, 29], [53, 71, 44, 65, 25, 43, 91, 52, 97, 51, 14], [70, 11, 33, 28, 77, 73, 17, 78, 39, 68, 17, 57], [91, 71, 52, 38, 17, 14, 91, 43, 58, 50, 27, 29, 48], [63, 66, 4, 68, 89, 53, 67, 30, 73, 16, 69, 87, 40, 31], [04, 62, 98, 27, 23, 9, 70, 98, 73, 93, 38, 53, 60, 4, 23], ] def expand_node(r, c): return [[r+1,c+0],[r+1,c+1]] all_paths = [] my_path = [] for i in xrange(0, len(triangle)): for j in xrange(0, len(triangle[i])): print 'row ', i, ' and col ', j, ' value is ', triangle[i][j] ??my_path = somehow chain these together??? if my_path not in all_paths all_paths.append(my_path) Answers that avoid external libraries (like itertools) preferred.

    Read the article

  • How to setPage() a JEditorPane with a localfile which is outside of the .jar file?

    - by Jaguar
    My program has the following path in the .jar file src/test/Program.class and my program is as follow... Program.java package test; import java.io.File; import java.io.IOException; import javax.swing.JEditorPane; import javax.swing.JFrame; public class Program { JEditorPane editorPane; public Program() { File file = new File("temp.htm"); try { file.createNewFile(); editorPane = new JEditorPane(); editorPane.setPage(Program.class.getResource("temp.htm")); } catch (IOException e) { e.printStackTrace(); } } public JEditorPane getEditorPane(){ return editorPane; } public static void main(String[] args) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(400, 400); frame.setVisible(true); Program p = new Program(); frame.getContentPane().add(p.getEditorPane()); } } The problem is that I have compiled the program in a .jar file. The file.createNewFile(); creates the temp.htm file outside the .jar file So when editorPane.setPage(Program.class.getResource("temp.htm")); is called the file is not found as it searches for file inside the test package. How to setPage() the temp.htm file whiich is outside the .jar file but in the same folder as the .jar file? As the temp.htm is a localfile and I want a relative path instead of an absolute path. Thanks.

    Read the article

  • Can you explicitly set a structure layout/alignment in C++ as you can in C#?

    - by Gary Willoughby
    In C# you have nice alignment attributes such as this: [StructLayout(LayoutKind.Explicit)] public struct Message { [FieldOffset(0)] public int a; [FieldOffset(4)] public short b; [FieldOffset(6)] public int c; [FieldOffset(22)] //Leave some empty space just for the heck of it. public DateTime dt; } Which gives you fine control on how you need your structure to be layed out in memory. Is there such a thing in standard C++?

    Read the article

  • is it possible to write a program which prints its own source code utilizing a "sequence-generating-

    - by guest
    is it possible to write a program which prints its own source code utilizing a "sequence-generating-function"? what i call a sequence-generating-function is simply a function which returns a value out of a specific interval (i.e. printable ascii-charecters (32-126)). the point now is, that this generated sequence should be the programs own source-code. as you see, implementing a function which returns an arbitrary sequence is really trivial, but since the returned sequence must contain the implementation of the function itself it is a highly non-trivial task. this is how such a program (and its corresponding output) could look like #include <stdio.h> int fun(int x) { ins1; ins2; ins3; . . . return y; } int main(void) { int i; for ( i=0; i<size of the program; i++ ) { printf("%c", fun(i)); } return 0; } i personally think it is not possible, but since i don't know very much about the underlying matter i posted my thoughts here. i'm really looking forward to hear some opinions!

    Read the article

  • Are there any platforms where using structure copy on an fd_set (for select() or pselect()) causes p

    - by Jonathan Leffler
    The select() and pselect() system calls modify their arguments (the 'struct fd_set *' arguments), so the input value tells the system which file descriptors to check and the return values tell the programmer which file descriptors are currently usable. If you are going to call them repeatedly for the same set of file descriptors, you need to ensure that you have a fresh copy of the descriptors for each call. The obvious way to do that is to use a structure copy: struct fd_set ref_set_rd; struct fd_set ref_set_wr; struct fd_set ref_set_er; ... ...code to set the reference fd_set_xx values... ... while (!done) { struct fd_set act_set_rd = ref_set_rd; struct fd_set act_set_wr = ref_set_wr; struct fd_set act_set_er = ref_set_er; int bits_set = select(max_fd, &act_set_rd, &act_set_wr, &act_set_er, &timeout); if (bits_set > 0) { ...process the output values of act_set_xx... } } My question: Are there any platforms where it is not safe to do a structure copy of the struct fd_set values as shown? I'm concerned lest there be hidden memory allocation or anything unexpected like that. (There are macros/functions FD_SET(), FD_CLR(), FD_ZERO() and FD_ISSET() to mask the internals from the application.) I can see that MacOS X (Darwin) is safe; other BSD-based systems are likely to be safe, therefore. You can help by documenting other systems that you know are safe in your answers. (I do have minor concerns about how well the struct fd_set would work with more than 8192 open file descriptors - the default maximum number of open files is only 256, but the maximum number is 'unlimited'. Also, since the structures are 1 KB, the copying code is not dreadfully efficient, but then running through a list of file descriptors to recreate the input mask on each cycle is not necessarily efficient either. Maybe you can't do select() when you have that many file descriptors open, though that is when you are most likely to need the functionality.) There's a related SO question - asking about 'poll() vs select()' which addresses a different set of issues from this question.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 119 120 121 122 123 124 125 126 127 128 129 130  | Next Page >