Note: I completely reworked the question to more properly reflect what I am setting the bounty for. Please excuse any inconsistencies with already-given answers this might have created. I did not want to create a new question, as previous answers to this one might be helpful. I am working on implementing a C standard library, and am c...
Hi, I want to have a C pre-preprocessor which is filtering some #define statements from the sourcecode without changing anything else. Why? This should be used to remove some client specific code from the sources if the source is handed out to another client. Does anyone know of an existing solution? Thanks! Simon ...
I have finished K&R book but I want to learn some more advanced things about C. Which book do you suggest me to read next? Something with data structures? Let me say that I have already read Sedgewick's "Data Structures in Java", if that helps. ...
This is a follow up to http://stackoverflow.com/questions/1417473/call-python-from-c At the startup of the programm I call the following function to initialize the interpreter: void initPython(){ PyEval_InitThreads(); Py_Initialize(); PyEval_ReleaseLock(); } Every thread creates it's own data structure and acquires the lo...
I would like to improve my C skills in order to be more competent at converting R code to C where this would be useful. What hints do people have that will help me on my way? Background: I followed an online Intro to C course a few years ago and that plus Writing R Extensions and S Programming (Venables & Ripley) enabled me to convert b...
What does this piece of code in C do: p = (1, 2.1); What do we know about p? ...
I realize that any such function is likely to be non standard, but that's ok for my use case. Basically, I need a method (even if it's only exposed through glibc's syscall() interface) that I can pass a pointer to (a pointer that was returned by a previous call to malloc()) that returns the size of the block the pointer points at. Does s...
Hi, I am using the following code in C to take input from user until EOF occur, but problem is this code is not working, it terminate after taking first input. Anyone can tell me whats wrong with this code. Thanks in Advance. float input; printf("Input No: "); scanf("%f", &input); while(!EOF) { printf("Output: %f"...
I have an objective-c application for OS X that compares two sqlite DB's and produces a diff in json format. The db are quite large (10,000 items with many fields). Sometimes this applications runs in about 55 sec(using 95% of the cpu). Sometimes it takes around 8 min (using 12% of the cpu). This is with the same DB's. When it is only us...
Here is the snippet of code typedef struct { double testA; double testB[500]; bool isProcessed; } MYSTURCT; I have a binary file which is written with multiple structs of type "myStruct". Now, in another function, I m trying to read the file and update in the middle. void test() { FILE* fp = fopen (testFile, "r+") ...
I'm getting into microcontroller hacking and while I'm very comfortable with bitwise operators and talking right to the hardware, I'm finding the resulting code very verbose and boilerplate. The higher level programmer in me wants to find an effective but efficient way to clean it up. For instance, there's a lot of setting flags in reg...
I'm using Beej's Guide to Networking and came across an aliasing issue. He proposes a function to return either the IPv4 or IPv6 address of a particular struct: 1 void *get_in_addr( struct sockaddr *sa ) 2 { 3 if (sa->sa_family == AF_INET) 4 return &(((struct sockaddr_in*)sa)->sin_addr); 5 else 6 return &(((st...
Unfortunately, search engines have failed me using this query. For instance: int foo = ~bar; ...
Greetings I am trying to learn C and finding myself getting stuck a lot, no complains : ) Anyway, I wrote a program and gcc does not like it, the following code is NOT the program but demonstrate the problem: #define MAXLINE = 1000 int main() { int tmp = MAXLINE; char line[MAXLINE]; return 0; } when compile, I get the fol...
With Bison, I figured out how to get everything into one long string as follows: arg_list: WORD arg_list { strcat( $1, "IFS" ); $$ = strcat($1, $2); } | WORD ; and: WORD arg_list { printf("%s, %s\n", $1, $2); } But the problem is that I will then have to split up $2 in the second rule again to parse it. Is there a way...
I'm trying to pull libcurl into a large C++ project. However I am having trouble getting it to compile. I see errors coming from ws2def.h, winsock2.h, and ws2tcpip.h Some of the errors look like this: error C2061: syntax error : identifier 'iSockaddrLength' ws2def.h 225 error C3646: 'LPSOCKADDR' : unknown override specifier ws2...
Working in an embedded (PIC) environment, programming in c. I have to keep track of 1000 values for a variable (history) and return the moving average of those values. I'm just wondering if it will be more efficient in terms of speed, ROM and RAM usage if I use an array or 1000 16bit variables. Is there a difinitive answer to that? O...
Ok, I have a control that want to fade in and out (continuously). In order to fade it I adjust the transparency value of the control in the drawing routine. So I set up a timer that runs and I adjust the m_transparency member. The timer runs and it should sweeps back and forth between the two defined values m_start, m_end. These can be 0...
I have a relatively trivial question. How can I check if a file has read permissions in C? thanks ...
I am trying to include a struct as part of the union with Bison, but I get an error on the 'struct node args' in %union: parser.y:17: error: field ‘args’ has incomplete type The Code: struct node { char * val; struct node * next; }; %} %union { char * string; struct node args; } %token <string> CD WORD PWD EXIT ...