c

How do I prevent buffer overflow converting a double to char?

I'm converting a double to a char string: char txt[10]; double num; num = 45.344322345 sprintf(txt, "%.1f", num); and using ".1f" to truncate the decimal places, to the tenths digit. i.e. - txt contains 45.3 I usually use precision in sprintf to ensure the char buffer is not overflowed. How can I do that here also truncating the de...

Can I use cstdio in a C program?

I get a ton of errors in cstdio when I add #include <cstdio> to the C program. c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\cstdio(17) : error C2143: syntax error : missing '{' before ':' c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\cstdio(17) : error C2059: syntax error : ':' Thanks EDIT - I would...

Objective-C global array of ints not working as expected

In my MyConstants.h file... I have: int abc[3]; In my matching MyConstants.m file... I have: extern int abc[3] = {11, 22, 33}; In each of my other *.m files... I have #import "MyConstants.h" Inside 1 of my viewDidLoad{} methods, I have: extern int abc[]; NSLog(@"abc = (%d) (%d)", abc[1], sizeof(abc)/sizeof(int)); Why does i...

Write to pipe deadlocking program

Hi, I am having a problem in my program that uses pipes. What I am doing is using pipes along with fork/exec to send data to another process What I have is something like this: //pipes are created up here if(fork() == 0) //child process { ... execlp(...); } else { ... fprintf(stderr, "Writing to pipe now\n"); write(pipe, ...

running a program in Unix vs in Windows

I'm compiling a simple program written in C and I'm using Eclipse as an IDE, both in Windows 7 and on my MacBook Pro. Very simple program my friend wrote and asked me to help him with: int a = 0; char b[2]; printf("Input first class info:\n"); printf("Credit Hours: \n"); scanf("%d", &a); printf("Letter Grade: "); scanf("%s", b); So wh...

Semantic errors

Can semantic errors be detected by the compiler or not? If not when do the errors get detected? As far as I know semantic errors are those errors which result from the expressions involving operators with incorrect number/type of operands. For example: n3=n1*n2;//n1 is integer, n2 is a string, n3 is an integer The above statement i...

Linear-time algorithms for sorting vertices in polygon contours

I figured out an algorithm that lets me turn my holed polygons into trapezoids in linear time if I have vertex indices sorted from lowest coordinate to highest. I get simple polygons as contours. They have certain order that might be exploited most of the time. So giving these conditions, is there a near-linear-time algorithm on sortin...

crash with CoUnintailize() api of COM

My main process(main.exe) initilaized COM library and created a thread which creates a new process(p1.exe) this new process is again initializing COM library and after making all references as zero unintialized COM here.. the unintailezed COM in the main process (i.e main.exe) also.... When i run p1.exe individually it is successful.. b...

error LNK2019 for ZLib sample code compiling.

Hello. I created win32 console application in vs2010 (without select the option of precompiled header). And I inserted the code below. but *.obj link failed. Could you provide me more information about the error. I searched MSDN, but still can't understand it. #include <stdio.h> #include "zlib.h" // Demonstration of zlib utility funct...

Initializing an array after declaration

Hello, gcc 4.4.3 c89 I have the following code as a sample of what I am trying to do. I don't know the actual size of the array, until I enter the function. However, I don't think I can set the array size after I have declared it. I need it global as some other functions will need to access the device names. Many thanks for any sugges...

Implementing a kext that intercepts file system usage.

Hi, how do most of antivirus software block file system io in case of an infected file? I suppose all the magic resides in some custom kext to do that. Can anyone point me to some topics on this? Some working example would also be great. I've read apple docs about kext development, but mostly it's all about hardware drivers and i could n...

Taming the malloc/free beast -- tips & tricks

I've been using C on some projects for a master's degree but have never built production software with it. (.NET & Javascript are my bread and butter.) Obviously, the need to free() memory that you malloc() is critical in C. This is fine, well and good if you can do both in one routine. But as programs grow, and structs deepen, keeping...

passing arg2 of 'listFind' from incompatible pointer type

Hello, I've got some problem with my function and don't know how to solve this problem, This is my code: ListResult result=listFind(currentLines, compareBasicLines, &linePrototype); <-here problem compareBasicLines pointer to function int compareBasicLines(ptrLine line1, ptrLine line2){ COMPARE_NUMBER_STRINGS(line1, line2); } ...

Interview questions for junior C and C++ developer position

What interview questions should people expect as a junior C and C++ developer? Code questions or more of theory? Solutions in pseudo-code or in C code? Maybe I'm misinterpreting the word "junior", but I have no idea what would anyone ask me if I have no C work experiences. I'm bit afraid of tricky questions with pointers, so I'd like to...

problem when trying to empty a stack in c

Hi all, (probably it's a stupid thing but) I have a problem with a stack implementation in C language, when I try to empty it, the function to empty the stack does an infinite loop.. the top of the stack is never null. where I commit an error? thanks bye! #include <stdio.h> #include <stdlib.h> typedef struct stack{ size_t a; struct...

stack dump accessing malloc char array

Hello, gcc 4.4.3 c89 I have the following source code. And getting a stack dump on the printf. char **devices; devices = malloc(10 * sizeof(char*)); strcpy(devices[0], "smxxxx1"); printf("[ %s ]\n", devices[0]); /* Stack dump trying to print */ I am thinking that this should create an char array like this. devices[0] devices[1] d...

An interview question

Hi, The questions shown below is an interview question Q)You are given have a datatype, say X in C. The requirement is to get the size of the datatype, without declaring a variable or a pointer variable of that type, And, of course without using sizeof operator ! I am not sure if this question was asked before in SO. Thanks and ...

Advanced example-driven C book with a lot of code.

Hello, I am looking for a book on advanced C programming that: Teaches how to effectively express one's solution in C when one already knows the language in depth, how to express useful practical abstractions. Shows some common design idioms expressed in C, like encapsulation, modularity and that kind of thing. Is example-driven with ...

How do I know which illegal address the program access when a segmentation fault happens

Plus, The program runs on a arm device running Linux, I can print out stack info and register values in the sig-seg handler I assign. The problem is I can't add -g option to the source file, since the bug may won't reproduce due to performance downgrade. ...

how to convert time of the day in UTC time?

i have time of the day in seconds and i have to find the utc time since 1970, is there any api which can directly convert this time to utc time, i m using ansi c , and working on windows platform platform independent api will be preferred thanx in advance. ...