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  • SSMS Results to Grid - CRLF not preserved in copy/paste - any better techniques?

    - by Cade Roux
    When I have a result set in the grid like: SELECT 'line 1 line 2 line 3' or SELECT 'line 1' + CHAR(13) + CHAR(10) + 'line 2' + CHAR(13) + CHAR(10) + 'line 3' With embedded CRLF, the display in the grid appears to replace them with spaces (I guess so that they will display all the data). The problem is that if I am code-generating a script, I cannot simply cut and paste this. I have to convert the code to open a cursor and print the relevant columns so that I can copy and paste them from the text results. Is there any simpler workaround to preserve the CRLF in a copy/paste operation from the results grid? The reason that the grid is helpful is that I am currently generating a number of scripts for the same object in different columns - a bcp out in one column, an xml format file in another, a table create script in another, etc...

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  • Function-Local Static Const variable Initialization semantics.

    - by Hassan Syed
    The questions are in bold, for those that cannot be bothered reading a question in depth. This is a followup to this question. It is to do with the initialization semantics of static variables in functions. Static variables should be initialized once, and their internal state might be altered later - as I (currently) do in the linked question. However, the code in question does not require the feature to change the state of the variable later. Let me clarrify my position, since I don't require the string object's internal state to change. The code is for a trait class for meta programming, and as such would would benifit from a const char * const ptr -- thus Ideally a local cost static const variable is needed. My educated guess is that in this case the string in question will be optimally placed in memory by the link-loader, and that the code is more secure and maps to the intended semantics. This leads to the semantics of such a variable "The C++ Programming language Third Edition -- Stroustrup" does not have anything (that I could find) to say about this matter. All that is said is that the variable is initialized once when the flow of control of the thread first reaches the code. This leads me to ponder if the following code would be sensible, and if not what are the intended semantics ?. #include <iostream> const char * const GetString(const char * x_in) { static const char * const x = x_in; return x; } int main() { const char * const temp = GetString("yahoo"); std::cout << temp << std::endl; const char * const temp2 = GetString("yahoo2"); std::cout << temp2 << std::endl; } The following compiles on GCC and prints "yahoo" twice. Which is what I want -- However it might not be standards compliant (which is why I post this question). It might be more elegant to have two functions, "SetString" and "String" where the latter forwards to the first. If it is standards compliant does someone know of a templates implementation in boost (or elsewhere) ?

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  • printf field width : bytes or chars?

    - by leonbloy
    The printf/fprintf/sprintf family supports a width field in its format specifier. I have a doubt for the case of (non-wide) char arrays arguments: Is the width field supposed to mean bytes or characters? What is the (correct-de facto) behaviour if the char array corresponds to (say) a raw UTF-8 string? (I know that normally I should use some wide char type, that's not the point) For example, in char s[] = "ni\xc3\xb1o"; // utf8 encoded "niño" fprintf(f,"%5s",s); Is that function supposed to try to ouput just 5 bytes (plain C chars) (and you take responsability of misalignments or other problems if two bytes results in a textual characters) ? Or is it supposed to try to compute the length of "textual characters" of the array? (decodifying it... according to the current locale?) (in the example, this would amount to find out that the string has 4 unicode chars, so it would add a space for padding).

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  • Strcpy() corrupts the copied string in Solaris but not Linux

    - by strictlyrude27
    Hi all, I'm writing a C code for a class. This class requires that our code compile and run on the school server, which is a sparc solaris machine. I'm running Linux x64. I have this line to parse (THIS IS NOT ACTUAL CODE BUT IS INPUT TO MY PROGRAM): while ( cond1 ){ I need to capture the "while" and the "cond1" into separate strings. I've been using strtok() to do this. In Linux, the following lines: char *cond = NULL; cond = (char *)malloc(sizeof(char)); memset(cond, 0, sizeof(char)); strcpy(cond, strtok(NULL, ": \t\(){")); //already got the "while" out of the line will correctly capture the string "cond1".Running this on the solaris machine, however, gives me the string "cone1". Note that in plenty of other cases within my program, strings are being copied correctly. (For instance, the "while") was captured correctly. Does anyone know what is going on here?

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  • C error conflicting types

    - by ambika
    i have following error error : conflicting types for 'sprintf' error : conflicting types for 'vsprintf' error : conflicting types for 'vprintf' error : conflicting types for 'select' in my header file, the code is extern char *sprintf(char*,const char*,... )

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  • F# exercise help - Beginner

    - by bobjink
    I hope you can help me with these exercises I have been stuck with. I am not in particular looking for the answers. Tips that help me solve them myself are just as good :) 1. Write a function implode : char list - string so that implode s returns the characters concatenated into a string: let implode (cArray:char list) = List.foldBack (+) 0 cArray;; Error. I am thinking that i need to cast every char to strings before I do the above. I bet however, that there is a much simpler and better solution. 2. Write a function palindrome : string - bool, so that palindrome s returns true if the string s is a palindrome let isIdentical cArray1 cArray2 = (cArray1 = cArray2);; let palinDrome (word:string) = isIdentical(word.ToCharArray(), Array.rev(word.ToCharArray()));; I get the value: val palinDrome : string - (char [] * char [] - bool), which is not what I want. 3. Write a function combinePair : int list - int list so that combinePair xs returns the list with elements from xs combined into pairs. If xs contains an odd number of elements, then the last element is thrown away: I have no idea for this one.

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  • problem with piping in my own implementation of shell

    - by codemax
    Hey guys, i am implementing my own shell. I want to involve piping. i searched here and i got a code. But it is not working.Can any one help me? this is my code #include <sys/types.h> #include <sys/wait.h> #include <sys/ipc.h> #include <fcntl.h> #include <unistd.h> #include <string.h> #include <iostream> #include <cstdlib> using namespace std; char temp1[81][81],temp2[81][81] ,*cmdptr1[40], *cmdptr2[40]; void process(char**,int); int arg_count, count; int arg_cnt[2]; int pip,tok; char input[81]; int fds[2]; void process( char* cmd[])//, int arg_count ) { pid_t pid; pid = fork(); //char path[81]; //getcwd(path,81); //strcat(path,"/"); //strcat(path,cmd[0]); if(pid < 0) { cout << "Fork Failed" << endl; exit(-1); } else if( pid == 0 ) { execvp( cmd[0] , cmd ); } else { wait(NULL); } } void pipe(char **cmd1, char**cmd2) { cout<<endl<<endl<<"in pipe"<<endl; for(int i=0 ; i<arg_cnt[0] ; i++) { cout<<cmdptr1[i]<<" "; } cout<<endl; for(int i=0 ; i<arg_cnt[1] ; i++) { cout<<cmdptr2[i]<<" "; } pipe(fds); if (fork() == 0 ) { dup2(fds[1], 1); close(fds[0]); close(fds[1]); process(cmd1); } if (fork() == 0) { dup2(fds[0], 0); close(fds[0]); close(fds[1]); process(cmd2); } close(fds[0]); close(fds[1]); wait(NULL); } void pipecommand(char** cmd1, char** cmd2) { cout<<endl<<endl; for(int i=0 ; i<arg_cnt[0] ; i++) { cout<<cmd1[i]<<" "; } cout<<endl; for(int i=0 ; i<arg_cnt[1] ; i++) { cout<<cmd2[i]<<" "; } int fds[2]; // file descriptors pipe(fds); // child process #1 if (fork() == 0) { // Reassign stdin to fds[0] end of pipe. dup2(fds[0], STDIN_FILENO); close(fds[1]); close(fds[0]); process(cmd2); // child process #2 if (fork() == 0) { // Reassign stdout to fds[1] end of pipe. dup2(fds[1], STDOUT_FILENO); close(fds[0]); close(fds[1]); // Execute the first command. process(cmd1); } wait(NULL); } close(fds[1]); close(fds[0]); wait(NULL); } void splitcommand1() { tok++; int k,done=0,no=0; arg_count = 0; for(int i=count ; input[i] != '\0' ; i++) { k=0; while(1) { count++; if(input[i] == ' ') { break; } if((input[i] == '\0')) { done = 1; break; } if(input[i] == '|') { pip = 1; done = 1; break; } temp1[arg_count][k++] = input[i++]; } temp1[arg_count][k++] = '\0'; arg_count++; if(done == 1) { break; } } for(int i=0 ; i<arg_count ; i++) { cmdptr1[i] = temp1[i]; } arg_cnt[tok] = arg_count; } void splitcommand2() { tok++; cout<<"count is :"<<count<<endl; int k,done=0,no=0; arg_count = 0; for(int i=count ; input[i] != '\0' ; i++) { k=0; while(1) { count++; if(input[i] == ' ') { break; } if((input[i] == '\0')) { done = 1; break; } if(input[i] == '|') { pip = 1; done = 1; cout<<"PIP"; break; } temp2[arg_count][k++] = input[i++]; } temp2[arg_count][k++] = '\0'; arg_count++; if(done == 1) { break; } } for(int i=0 ; i<arg_count ; i++) { cmdptr2[i] = temp2[i]; } arg_cnt[tok] = arg_count; } int main() { cout<<endl<<endl<<"Welcome to unique shell !!!!!!!!!!!"<<endl; tok=-1; while(1) { cout<<endl<<"***********UNIQUE**********"<<endl; cin.getline(input,81); count = 0,pip=0; splitcommand1(); if(pip == 1) { count++; splitcommand2(); } cout<<endl<<endl; if(strcmp(cmdptr1[0], "exit") == 0 ) { cout<<endl<<"EXITING UNIQUE SHELL"<<endl; exit(0); } //cout<<endl<<"Arg count is :"<<arg_count<<endl; if(pip == 1) { cout<<endl<<endl<<"in main :"; for(int i=0 ; i<arg_cnt[0] ; i++) { cout<<cmdptr1[i]<<" "; } cout<<endl; for(int i=0 ; i<arg_cnt[1] ; i++) { cout<<cmdptr2[i]<<" "; } pipe(cmdptr1, cmdptr2); } else { process (cmdptr1);//,arg_count); } } } I know it is not well coded. But try to help me :(

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  • Read variable-length records from a buffer - weird memory issues

    - by bsg
    Hi, I'm trying to implement an i/o intensive quicksort (C++ qsort) on a very large dataset. In the interests of speed, I'd like to read in a chunk of data at a time into a buffer and then use qsort to sort it inside the buffer. (I am currently working with text files but would like to move to binary soon.) However, my data is composed of variable-length records, and qsort needs to be told the length of the record in order to sort. Is there any way to standardize this? The only thing I could think of was rather convoluted: my program currently reads from the buffer until it hits a linefeed character ('10' in ascii), transferring each character over to another array. When it finds a linefeed (the delimiter in the input file), it fills the number of spaces remaining in the buffer for that record (record size is set to 30) with null characters. This way, I should end up with a buffer full of fixed-size records to give qsort. I know there are several problems with my approach, one being that it's just clumsy, another that the record size might conceivably be larger than 30, but is generally much less. Is there a better way of doing this? As well, my current code doesn't even work. When I debug it, it seems to be transferring characters from one buffer to the other, but when I try to print out the buffer, it contains only the first record. Here is my code: FILE *fp; unsigned char *buff; unsigned char *realbuff; FILE *inputFiles[NUM_INPUT_FILES]; buff = (unsigned char *) malloc(2048); realbuff = (unsigned char *) malloc(NUM_RECORDS * RECORD_SIZE); fp = fopen("postings0.txt", "r"); if(fp) { fread(buff, 1, 2048, fp); /*for(int i=0; i <30; i++) cout << buff[i] <<endl;*/ int y=0; int recordcounter = 0; //cout << buff; for(int i=0;i <100; i++) { if(buff[i] != char(10)) { realbuff[y] = buff[i]; y++; recordcounter++; } else { if(recordcounter < RECORD_SIZE) for(int j=recordcounter; j < RECORD_SIZE;j++) { realbuff[y] = char(0); y++; } recordcounter = 0; } } cout << realbuff <<endl; cout << buff; } else cout << "sorry"; Thank you very much, bsg

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  • Problem implementing sorting algorithm in C with an array of structs

    - by dilog
    Well here is my little problem, first my code: struct alumn { char name[100]; char lastname[100]; int par; int nota; }; typedef struct alumn alumn; int bubble(alumn **arr, int length) { int i,j; alumn *temp; for (i=0; i<=length-2; i++) { for (j=i+1; j<=length-1;j++) { if ((*arr)[i].nota > (*arr)[j].nota) { temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } } } } int main(int argc, char **argv) { alumn *alumns; ... here goes some other code ... bubble(&alumns,totalAlumns); return 0; } My problem is that this algorith is not sorting anything. I'm having a hard time doing the swap, i tried everything but nothing works :( . Any help??? struct alumn { char name[100]; char lastname[100]; int par; int nota; }; typedef struct alumn alumn; int bubble(alumn **arr, int length) { int i,j; alumn *temp; for (i=0; i<=length-2; i++) { for (j=i+1; j<=length-1;j++) { if ((*arr)[i].nota > (*arr)[j].nota) { temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } } } } int main(int argc, char **argv) { alumn *alumns; ... here goes some other code ... bubble(&alumns,totalAlumns); return 0; } My problem is that this algorith is not sorting anything. I'm having a hard time doing the swap, i tried everything but nothing works :( . Any help???

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  • send c++ structure to msmq message

    - by Gobalakrishnan
    C++ Code: typedef struct { char cfiller[7]; short MsgCode; char cfiller1[11]; short MsgLength; char cfiller2[2]; }Message ; I want to send the above structure as a msmq message I am able to send string to msmq but it is giving error to send the above structure. thank you

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  • Can parser combination be made efficient?

    - by Jon Harrop
    Around 6 years ago, I benchmarked my own parser combinators in OCaml and found that they were ~5× slower than the parser generators on offer at the time. I recently revisited this subject and benchmarked Haskell's Parsec vs a simple hand-rolled precedence climbing parser written in F# and was surprised to find the F# to be 25× faster than the Haskell. Here's the Haskell code I used to read a large mathematical expression from file, parse and evaluate it: import Control.Applicative import Text.Parsec hiding ((<|>)) expr = chainl1 term ((+) <$ char '+' <|> (-) <$ char '-') term = chainl1 fact ((*) <$ char '*' <|> div <$ char '/') fact = read <$> many1 digit <|> char '(' *> expr <* char ')' eval :: String -> Int eval = either (error . show) id . parse expr "" . filter (/= ' ') main :: IO () main = do file <- readFile "expr" putStr $ show $ eval file putStr "\n" and here's my self-contained precedence climbing parser in F#: let rec (|Expr|) (P(f, xs)) = Expr(loop (' ', f, xs)) and shift oop f op (P(g, xs)) = let h, xs = loop (op, g, xs) loop (oop, f h, xs) and loop = function | ' ' as oop, f, ('+' | '-' as op)::P(g, xs) | (' ' | '+' | '-' as oop), f, ('*' | '/' as op)::P(g, xs) | oop, f, ('^' as op)::P(g, xs) -> let h, xs = loop (op, g, xs) let op = match op with | '+' -> (+) | '-' -> (-) | '*' -> (*) | '/' -> (/) | '^' -> pown loop (oop, op f h, xs) | _, f, xs -> f, xs and (|P|) = function | '-'::P(f, xs) -> let f, xs = loop ('~', f, xs) P(-f, xs) | '('::Expr(f, ')'::xs) -> P(f, xs) | c::xs when '0' <= c && c <= '9' -> P(int(string c), xs) My impression is that even state-of-the-art parser combinators waste a lot of time back tracking. Is that correct? If so, is it possible to write parser combinators that generate state machines to obtain competitive performance or is it necessary to use code generation?

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  • seg fault caused by malloc and sscanf in a function

    - by Framester
    Hi, I want to open a text file (see below), read the first int in every line and store it in an array, but I get an segmentation fault. I got rid of all gcc warnings, I read through several tutorials I found on the net and searched stackoverflow for solutions, but I could't make out, what I am doing wrong. It works when I have everything in the main function (see example 1), but not when I transfer it to second function (see example 2 further down). In example 2 I get, when I interpret gdb correctly a seg fault at sscanf (line,"%i",classes[i]);. I'm afraid, it could be something trivial, but I already wasted one day on it. Thanks in advance. [Example 1] Even though that works with everything in main: #include<stdio.h> #include<stdlib.h> #include<string.h> const int LENGTH = 1024; int main() { char *filename="somedatafile.txt"; int *classes; int lines; FILE *pfile = NULL; char line[LENGTH]; pfile=fopen(filename,"r"); int numlines=0; char *p; while(fgets(line,LENGTH,pfile)){ numlines++; } rewind(pfile); classes=(int *)malloc(numlines*sizeof(int)); if(classes == NULL){ printf("\nMemory error."); exit(1); } int i=0; while(fgets(line,LENGTH,pfile)){ printf("\n"); p = strtok (line," "); p = strtok (NULL, ", "); sscanf (line,"%i",&classes[i]); i++; } fclose(pfile); return 1; } [Example 2] This does not with the functionality transfered to a function: #include<stdio.h> #include<stdlib.h> #include<string.h> const int LENGTH = 1024; void read_data(int **classes,int *lines, char *filename){ FILE *pfile = NULL; char line[LENGTH]; pfile=fopen(filename,"r"); int numlines=0; char *p; while(fgets(line,LENGTH,pfile)){ numlines++; } rewind(pfile); * classes=(int *)malloc(numlines*sizeof(int)); if(*classes == NULL){ printf("\nMemory error."); exit(1); } int i=0; while(fgets(line,LENGTH,pfile)){ printf("\n"); p = strtok (line," "); p = strtok (NULL, ", "); sscanf (line,"%i",classes[i]); i++; } fclose(pfile); *lines=numlines; } int main() { char *filename="somedatafile.txt"; int *classes; int lines; read_data(&classes, &lines,filename) ; for(int i=0;i<lines;i++){ printf("\nclasses[i]=%i",classes[i]); } return 1; } [Content of somedatafile.txt] 50 21 77 0 28 0 27 48 22 2 55 0 92 0 0 26 36 92 56 4 53 0 82 0 52 -5 29 30 2 1 37 0 76 0 28 18 40 48 8 1 37 0 79 0 34 -26 43 46 2 1 85 0 88 -4 6 1 3 83 80 5 56 0 81 0 -4 11 25 86 62 4 55 -1 95 -3 54 -4 40 41 2 1 53 8 77 0 28 0 23 48 24 4 37 0 101 -7 28 0 64 73 8 1 ...

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  • C# wrapper for array of three pointers

    - by fergs
    I'm currently working on a C# wrapper to work with Dallmeier Common API light. See previous posting: http://stackoverflow.com/questions/2430089/c-wrapper-and-callbacks I've got pretty much everything 'wrapped' but I'm stuck on wrapping a callback which contains an array of three pointers & an array integers: dlm_setYUVDataCllback int(int SessionHandle, void (*callback) (long IPlayerID, unsigned char** yuvData, int* pitch, int width, int height, int64_t ts, char* extData)) Function Set callback, to receive current YUV image. Arguments SessionHandle: handle to current session. Return PlayerID (see callback). Callback - IPlayerId: id to the Player object - yuvData: array of three pointers to Y, U and V part of image The YUV format used is YUV420 planar (not packed). char *y = yuvData[0]; char *u = yuvData[1]; char *v = yuvData[2]; - pitch: array of integers for pitches for Y, U and V part of image - width: intrinsic width of image. - height - ts : timestamp of current frame - extData: additional data to frame How do I go about wrapping this in c#? Any help is much appreciated.

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  • sqlite issues on iphone

    - by prajakta
    i can execute query but i can see the only last value of list_ID i want to access 4 but i am getting 6 ??? list_ID is ----------------------->is 4 2010-12-24 12:57:07.507 DatabaseTest[3398:207] QUERY EXECUTION 2010-12-24 12:57:07.508 DatabaseTest[3398:207] bxbxbxmnb 2010-12-24 12:57:07.508 DatabaseTest[3398:207] list_ID is ----------------------->is 5 2010-12-24 12:57:07.509 DatabaseTest[3398:207] QUERY EXECUTION 2010-12-24 12:57:07.510 DatabaseTest[3398:207] bxbxbxmnb 2010-12-24 12:57:07.511 DatabaseTest[3398:207] list_ID is ----------------------->is 6 this is the code if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { while(sqlite3_step(compiledStatement) == SQLITE_ROW) { acat=[[[Cat_tableList alloc]init]autorelease]; ///////////// statement//////// NSLog(@" QUERY EXECUTION"); // sStudent.cat_id=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)]; acat.list_id=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)]; acat.cat_id=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)]; acat.names=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)]; acat.content=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)]; [appDelegate.catLists addObject:acat]; (@"final AUTo_ID array is ............%@",acat.content); NSLog(@" list_ID is ----------------------->is %@",acat.list_id); i just want value to b 4 so that i can use this somewhere /////////////// }

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  • conflicting declaration when filling a static std::map class member variable

    - by Max
    I have a class with a static std::map member variable that maps chars to a custom type Terrain. I'm attempting to fill this map in the class's implementation file, but I get several errors. Here's my header file: #ifndef LEVEL_HPP #define LEVEL_HPP #include <bitset> #include <list> #include <map> #include <string> #include <vector> #include "libtcod.hpp" namespace yarl { namespace level { class Terrain { // Member Variables private: std::bitset<5> flags; // Member Functions public: explicit Terrain(const std::string& flg) : flags(flg) {} (...) }; class Level { private: static std::map<char, Terrain> terrainTypes; (...) }; } } #endif and here's my implementation file: #include <bitset> #include <list> #include <map> #include <string> #include <vector> #include "Level.hpp" #include "libtcod.hpp" using namespace std; namespace yarl { namespace level { /* fill Level::terrainTypes */ map<char,Terrain> Level::terrainTypes['.'] = Terrain("00001"); // clear map<char,Terrain> Level::terrainTypes[','] = Terrain("00001"); // clear map<char,Terrain> Level::terrainTypes['\''] = Terrain("00001"); // clear map<char,Terrain> Level::terrainTypes['`'] = Terrain("00001"); // clear map<char,Terrain> Level::terrainTypes[178] = Terrain("11111"); // wall (...) } } I'm using g++, and the errors I get are src/Level.cpp:15: error: conflicting declaration ‘std::map, std::allocator yarl::level::Level::terrainTypes [46]’ src/Level.hpp:104: error: ‘yarl::level::Level::terrainTypes’ has a previous declaration as ‘std::map, std::allocator yarl::level::Level::terrainTypes’ src/Level.cpp:15: error: declaration of ‘std::map, std::allocator yarl::level::Level::terrainTypes’ outside of class is not definition src/Level.cpp:15: error: conversion from ‘yarl::level::Terrain’ to non-scalar type ‘std::map, std::allocator ’ requested src/Level.cpp:15: error: ‘yarl::level::Level::terrainTypes’ cannot be initialized by a non-constant expression when being declared I get a set of these for each map assignment line in the implementation file. Anyone see what I'm doing wrong? Thanks for your help.

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  • Why subtract null pointer in offsetof()?

    - by Bruce Christensen
    Linux's stddef.h defines offsetof() as: #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) whereas the Wikipedia article on offsetof() (http://en.wikipedia.org/wiki/Offsetof) defines it as: #define offsetof(st, m) \ ((size_t) ( (char *)&((st *)(0))->m - (char *)0 )) Why subtract (char *)0 in the Wikipedia version? Is there any case where that would actually make a difference?

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  • Easiest way of checking if a string consists of unique characters?

    - by serg555
    I need to check in Java if a word consists of unique letters (case insensitive). As straight solution is boring, I came up with: For every char in a string check if indexOf(char) == lastIndexOf(char). Add all chars to HashSet and check if set size == string length. Convert a string to a char array, sort it alphabetically, loop through array elements and check if c[i] == c[i+1]. Currently I like #2 the most, seems like the easiest way. Any other interesting solutions?

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  • puts() a pointer in C

    - by Sergey Gavruk
    I have a function: char *make_text(void) { char txt[MAXLEN]; //make something return txt; } Thats my main program: int main(void) { char *s = make_text(); puts(s); getch(); return 0; } puts(s) returns 0 and its nothing printed. Whats happened?

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  • C - struct problems - writing

    - by Catarrunas
    Hello, I'm making a program in C, and I'mm having some troubles with memory, I think. So my problem is: I have 2 functions that return a struct. When I run only one function at a time I have no problem whatsoever. But when I run one after the other I always get an error when writting to the second struct. Function struct item* ReadFileBIN(char *name) -- reads a binary file. struct tables* getMesasInfo(char* Filename) -- reads a text file. My code is this: #include "stdafx.h" #include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> int numberOfTables=0; int numberOfItems=0; //struct tables* mesas; //struct item* Menu; typedef struct item{ char nome[100]; int id; float preco; }; typedef struct tables{ int id; int capacity; bool inUse; }; struct tables* getMesasInfo(char* Filename){ struct tables* mesas; char *c; int counter,numberOflines=0,temp=0; char *filename=Filename; FILE * G; G = fopen(filename,"r"); if (G==NULL){ printf("Cannot open file.\n"); } else{ while (!feof(G)){ fscanf(G, "%s", &c); numberOflines++; } fclose(G); } /* Memory allocate for input array */ mesas = (struct tables *)malloc(numberOflines* sizeof(struct tables*)); counter=0; G=fopen(filename,"r"); while (!feof(G)){ mesas[counter].id=counter; fscanf(G, "%d", &mesas[counter].capacity); mesas[counter].inUse= false; counter++; } fclose(G); numberOfTables = counter; return mesas; } struct item* ReadFileBIN(char *name) { int total=0; int counter; FILE *ptr_myfile; struct item my_record; struct item* Menu; ptr_myfile=fopen(name,"r"); if (!ptr_myfile) { printf("Unable to open file!"); } while (!feof(ptr_myfile)){ fread(&my_record,sizeof(struct item),1,ptr_myfile); total=total+1; } numberOfItems=total-1; Menu = (struct item *)calloc(numberOfItems , sizeof(struct item)); fseek(ptr_myfile, sizeof(struct item), SEEK_END); rewind(ptr_myfile); for ( counter=1; counter < total ; counter++) { fread(&my_record,sizeof(struct item),1,ptr_myfile); Menu[counter] = my_record; printf("Nome: %s\n",Menu[counter].nome); printf("ID: %d\n",Menu[counter].id); printf("Preco: %f\n",Menu[counter].preco); } fclose(ptr_myfile); return Menu; } int _tmain(int argc, _TCHAR* argv[]) { struct item* tt = ReadFileBIN("menu.dat"); struct tables* t = getMesasInfo("Capacity.txt"); getchar(); }** Thanks in advance.

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  • Variable lenght arguments in log4cxx LOG4CXX_ macros

    - by Horacio
    I am using log4cxx in a big C++ project but I really don't like how log4cxx handles multiple variables when logging: LOG4CXX_DEBUG(logger, "test " << var1 << " and " << var3 " and .....) I prefer using printf like variable length arguments: LOG4CXX_DEBUG(logger, "test %d and %d", var1, var3) So I implemented this small wrapper on top of log4cxx #include <string.h> #include <stdio.h> #include <stdarg.h> #include <log4cxx/logger.h> #include "log4cxx/basicconfigurator.h" const char * log_format(const char *fmt, ...); #define MYLOG_TRACE(logger, fmt, ...) LOG4CXX_TRACE(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_DEBUG(logger, fmt, ...) LOG4CXX_DEBUG(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_INFO(logger, fmt, ...) LOG4CXX_INFO(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_WARN(logger, fmt, ...) LOG4CXX_WARN(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_ERROR(logger, fmt, ...) LOG4CXX_ERROR(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_FATAL(logger, fmt, ...) LOG4CXX_FATAL(logger, log_format(fmt, ## __VA_ARGS__)) static log4cxx::LoggerPtr logger(log4cxx::Logger::getRootLogger()); int main(int argc, char **argv) { log4cxx::BasicConfigurator::configure(); MYLOG_INFO(logger, "Start "); MYLOG_WARN(logger, log_format("In running this in %d threads safe?", 1000)); MYLOG_INFO(logger, "End "); return 0; } const char *log_format(const char *fmt, ...) { va_list va; static char formatted[1024]; va_start(va, fmt); vsprintf(formatted, 1024, fmt, va); va_end(va); return formatted; } And this works perfectly but I know using that static variable (formatted) can become problematic if I start using threads and each thread logging to the same place. I am no expert in log4cxx so I was wondering if the LOG4CXX macros are handling concurrent thread access automatically? or do I have to implement some sort of locking around the log_format method? something that I wan't to avoid due to performance implications. Also I would like to ask why if I replace the vsprintf inside the log_format method with vsnprintf (that is more secure) then I get nothing printed? To compile and test this program (in Ubuntu) use : g++ -o loggertest loggertest.cpp -llog4cxx

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  • PhysX SDK - error LNK2019: unresolved external symbol when compiling "wavefront.cpp"

    - by user370102
    Hi all, I'm using the PhysX SDK and I'm trying to load an .obj file with the WavefrontObj object which is defined by the files "wavefront.h/.cpp", localized in the samples directory. When I'm compiling my project, I got this error: 1Linking... 1wavefront.obj : error LNK2019: unresolved external symbol "char * __cdecl FindMediaFile(char const *,char *)" (?FindMediaFile@@YAPADPBDPAD@Z) referenced in function "public: void __thiscall WAVEFRONT::InPlaceParser::SetFile(char const *)" (?SetFile@InPlaceParser@WAVEFRONT@@QAEXPBD@Z) 1C:\Users\Nicolas\Documents\GI05\CSED451 - Computer Graphics\ToyFK_Project\Debug\ToyFK_Project.exe : fatal error LNK1120: 1 unresolved externals I guess I forgot to link a library or something but I really can't find what... It's driving me crazy!!! Does somebody have an idea? Thank you

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  • How can I free all allocated memory at once?

    - by Tommy
    Here is what I am working with: char* qdat[][NUMTBLCOLS]; char** tdat[]; char* ptr_web_data; // Loop thru each table row of the query result set for(row_index = 0; row_index < number_rows; row_index++) { // Loop thru each column of the query result set and extract the data for(col_index = 0; col_index < number_cols; col_index++) { ptr_web_data = (char*) malloc((strlen(Data) + 1) * sizeof(char)); memcpy (ptr_web_data, column_text, strlen(column_text) + 1); qdat[row_index][web_data_index] = ptr_web_data; } } tdat[row_index] = qdat[col_index]; After the data is used, the memory allocated is released one at a time using free(). for(row_index = 0; row_index < number_rows; row_index++) { // Loop thru all columns used for(col_index = 0; col_index < SARWEBTBLCOLS; col_index++) { // Free memory block pointed to by results set array free(tdat[row_index][col_index]); } } Is there a way to release all the allocated memory at once, for this array? Thank You.

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  • o 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.

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  • The Implications of Modern Day Software Development Abstractions

    - by Andreas Grech
    I am currently doing a dissertation about the implications or dangers that today's software development practices or teachings may have on the long term effects of programming. Just to make it clear: I am not attacking the use abstractions in programming. Every programmer knows that abstractions are the bases for modularity. What I want to investigate with this dissertation are the positive and negative effects abstractions can have in software development. As regards the positive, I am sure that I can find many sources that can confirm this. But what about the negative effects of abstractions? Do you have any stories to share that talk about when certain abstractions failed on you? The main concern is that many programmers today are programming against abstractions without having the faintest idea of what the abstraction is doing under-the-covers. This may very well lead to bugs and bad design. So, in you're opinion, how important is it that programmers actually know what is going below the abstractions? Taking a simple example from Joel's Back to Basics, C's strcat: void strcat( char* dest, char* src ) { while (*dest) dest++; while (*dest++ = *src++); } The above function hosts the issue that if you are doing string concatenation, the function is always starting from the beginning of the dest pointer to find the null terminator character, whereas if you write the function as follows, you will return a pointer to where the concatenated string is, which in turn allows you to pass this new pointer to the concatenation function as the *dest parameter: char* mystrcat( char* dest, char* src ) { while (*dest) dest++; while (*dest++ = *src++); return --dest; } Now this is obviously a very simple as regards abstractions, but it is the same concept I shall be investigating. Finally, what do you think about the issue that schools are preferring to teach Java instead of C and Lisp ? Can you please give your opinions and your says as regards this subject? Thank you for your time and I appreciate every comment.

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