Useful notepad++ plugins for C / C++ developement?
What are all the helpful plugins available for C / C++ development? ...
c
Is storing an invalid pointer automatically undefined behavior?
Obviously, dereferencing an invalid pointer causes undefined behavior. But what about simply storing an invalid memory address in a pointer variable? Consider the following code: const char* str = "abcdef"; const char* begin = str; if (begin - 1 < str) { /* ... do something ... */ } The expression begin - 1 evaluates to an invalid m...
What is the sizeof(main), sizeof(printf), sizeof(scanf)?
In the gcc compiler, sizeof(main), sizeof(printf) and sizeof(scanf) all are 1. I want to know how the size of all these are 1. What is the logic behind it? ...
How to properly define a function pointer in struct, which takes struct as a pointer?
I have a struct with a callback function, the callback function needs a pointer to the structure in order to do its operation. How do I properly define these elements such that is will compile without warnings? typedef struct { // some fields required for processing... int (*doAction)(struct pr_PendingResponseItem *pr); } pr_P...
Can we use main, printf,scanf for naming identifiers ?
int main() { int main=5; printf("%d",main); return 0; } In this case there is no error and the gcc compiler prints 5. But if I write int main() { int printf=5; printf("%d",printf); return 0; } the compiler shows an error..why ? ...
A short programming puzzle
What could the possible explanation for the following puzzle : #include <stdio.h> int main(){ static char *s[] = {"black","white","yellow","violet"}; char *ptr[] = {s+3,s+2,s+1,s},***p; p = ptr; *++p; printf("%s",*--*++p + 3); } output. ...
How %g rounds up floating point numbers ?
While I'm using %g as format specifier in printf(), sometimes it rounds up upto 2 places after decimal point, sometimes upto 3 places , someimes upto 4 places...how it does so ? Actually where we should use %g instead of %f or %e for floating point numbers..? ...
How to safety parse tab-delimiter string ?
How to safety parse tab-delimiter string ? for example: test\tbla-bla-bla\t2332 ? ...
Confusion in floating point numbers..
int main() { float x=3.4e2; printf("%f",x); return 0; } Output: 340.000000 // It's ok. But if i'm taking x=3.1234e2, the output is 312.339996 and if x=3.12345678e2 ,the output is 312.345673 why the outputs are like these ? I think if I write x=3.1234e2 , the output will be 312.340000 but the actual output is 312.339996 in gcc c...
What is the output of the following code ?
int main() { int x=5,y=10,z=15; printf("%d %d %d"); return 0; } Output: 15 10 5 //In Turbo C 4.5 3 Garbage values in gcc compiler My teacher told me when we define the variables like int x=5,y=10,z=15; they are by default taken as auto type and stored in stack.When you try print 3 integer values without using their names ...
aligned malloc() in GCC?
Hi. Is there any standardized function in GCC or glibc to allocate memory block at aligned pointer? Like _align_malloc() in MSVC? ...
Xcode leaks tool not showing object for a single massive leak made by realloc I'm guessing.
Hello. I have some code which has a memory leak. It's in development still so this is expected to happen but I can't find where the memory leak occurs. I try using the leaks tool and it shows an allocation like this (The 1.17MB steadily increases through the program): Category: Malloc 1.17MB Live/Overall Bytes: 1.17MB Obviously for on...
Using C++ libraries
Hi whole of our project development is in C. However there are alot of string operations here and there and how much care we make .. we endup having coding errors in string operations and this results most of the time in for buffer overflows ..stack corruptions etc. due to programmers fault. How nice is this idea to just use C++ strin...
Still Reachable Leak detected by Valgrind
All the functions mentioned in this block are library functions. How can I rectify this memory leak? It is listed under the "Still reachable" category. (There are 4 more, which are very similar, but of varying sizes) 630 bytes in 1 blocks are still reachable in loss record 5 of 5 at 0x4004F1B: calloc (vg_replace_malloc.c:418) ...
How many bytes are dynamically allocated in the following code segment?
Assuming that a memory address occupies 4 bytes and a char occupies 1 byte: char** t; t = malloc(5 * sizeof(char*)); int i; for (i = 0; i < 5; i++) t[i] = malloc(sizeof(char) * (i+1)); ...
cblas_dgemm - correct parameters : incorrect error message
I am trying to compute: C = 1*(A*B') + 0*C using cblas_dgemm(). As far as I can tell, the parameters are correct. The error message itself does not make sense: "ldb must be >= MAX(K,1): ldb=3 K=3Parameter 11 to routine cblas_dgemm was incorrect" But, ldb = k = 3! Here is the detailed output of all three matrices and the parameters. ...
Tool to extract theme parts
I'm looking for a tool to extract the theme parts and save them as pngs. By this I mean, Pushbutton, Start orb, etc. I found an application that can display the theme parts but I cannot save them into a format with an alpha channel. Thanks ...
lib curl symbol not found
Really stupid C question. I'm trying to build the source code here so I can start on modifying it for myself http://curl.haxx.se/libcurl/c/ftpget.html I download the file, then run gcc -o test ftpget.c and get Undefined symbols: "_curl_global_init", referenced from: _main in ccFchguB.o "_curl_easy_perform", referenced fr...
Keyboard repeat count
Hello i am having trouble utilising the repeat count parameter of the msg WM_KEYDOWN ... using visual c++ 2008 for some reason or the other the repeat count of the msg does not increment if the key is held for long.... for eg if i use this code:: ---------- *TextOut(hdc,cxChar*2*(sizeof(szBuffer)/sizeof(TCHAR)),i*cyChar,szBuffer,wspri...
Typedef struct question
Why would I want to do this? typedef struct Frame_s { int x; int y; int z; } Frame_t; Also if I want to create an object what do I use Frame_s or Frame_t? ...