I want to allocate some memory in C and keep it associated with a java object instance, like this: void configure(JNIEnv *object, jobject obj, ....) { char *buf = new char[1024]; // associated <buf> with <obj> somehow } And then later free the memory when the java object gets garbage collected - I could do this by calling a JNI fu...
#define PLAINTEXT_TARGET "plaintext" if( strstr(PLAINTEXT_TARGET, optarg) == PLAINTEXT_TARGET ) /* ... */ Does the C language guarantee that PLAINTEXT_TARGET above compiles into a single instance? If the compiler may produce two instances of the macro string then the conditional above is misleading and can be false. ...
I'm abusing the C preprocessor for my build system to produce a "readme" plain-text file and a web page from the same source file. The construction is something like this: The actual definitions are in data.h: #define WEBSITE "http://example.com" Note that the // in the URL must be quoted, or else it will be treated as the start of a...
I am referring to http://www.postgresql.org/docs/8.1/static/libpq.html I try to find an example of C/C++ to call PostgreSQL stored procedure. However, I cannot find one. Can anyone point me the right direction? ...
Is there any compiler option to make time_t 64-bit in Solaris 5.8 in forte compiler. I need to develop library in 32-bit and I cannot change it to 64-bit as it effects existing client applications. ...
In Win32 API programming it's typical to use C structs with multiple fields. Usually only a couple of them have meaningful values and all others have to be zeroed out. This can be achieved in either of the two ways: STRUCT theStruct; memset( &theStruct, 0, sizeof( STRUCT ) ); or STRUCT theStruct = {}; The second variant looks clean...
How can I measure the power consumed by a C algorithm while running on a Pentium 4 processor (and any other processor will also do)? ...
int i = 3.1 / 2 does not cause any warnings,even with -Wall option.Sometimes,I would like to know where precision lose.Why gcc does not support this warning,while msvc support this one? thanks. EDIT: my gcc -v shows Configured with: ../../gcc-4.4.1/configure --prefix=/mingw --build=mingw32 --enable-languages=c,ada,c++,fortran,objc,o...
Hi, I'm practicing C programming for Linux for an exam. I don't know how to exit the program when user press Ctrl + a ( not Ctrl+c ) For example, looping something until user press Ctrl+a Could anyone tell me how to check Ctrl+a input? Notes: I'm using 'gcc' and run output with './a.out' Thanks in advance for everyone! ...
I have some compiled libraries on x86 Linux and I want to quickly determine whether they were compiled with debugging symbols. ...
Is it possible to get the screen pixel resolution in mm using Win32 APIs ? I have an application which is showing 0.3472222222222222 as the value for this on my 1280x1024 monitor with 96 dpi . But I am not able to find out how it got this value. Any clues will be helpful. I can use MFC also if required. EDIT Sorry for the confusion, the...
I have come across a problem while writing a fairly simple program. I have a statically allocated vector as a global variable and in a function I'm trying to change the values of the elements and that is when the program stops and says segmentation fault. The code is something like this: int a[10] = {0,0,0,0,0,0,0,0,0,0}; ... int bla(...
For OOP languages, there are many books describing how to design software, and design patterns are mainly for OOP languages. I am wondering whether there are any books/good articles teaching how to use C in a big project, like it is a good practice to use static functions when this function is only used in a single file. ...
I'm developing a dedicated game server on a linux machine, in C/C++ (mixed). I have the following snippet of code: int sockfd=socket(AI_INET, SOCK_DGRAM, 0); if(sockfd==-1) { int err=errno; fprintf(stderr,"%s",strerror(err)); exit(1); } My problem here, is that socket is returning -1 (implying a failure) and the error stri...
Where can I find some good, proven guidelines or examples on writing extensible, modular, loosely-coupled code in C (if possible)? Background of our problem is that we are maintaining large plain C, legacy code project for a low-cost microcontroller with limited computing and memory resources. Due to the fact that the system must be ex...
Came across this conditional in some uncommented Objective-C code: if (w & (w - 1)) { i = 1; while (i < w) { i *= 2; } w = i; } Where w is a size_t greater than 1. Update: Added the code contained by the conditional for context. ...
Hi, I'm working on a C application that is suppose to talk to PostgreSQL. Right now I need to handle notices and warnings sent by the server but I'm at a loss on how to make it work. The (very unclear) documentation says we should use PQsetNoticeReceiver to set a method as the receiver of notifications, as the default receiver just for...
I am trying to recompile solution file for memcached project on Windows 7 64 bit with Visual Studio 2008 and got the following error: 1>LINK : fatal error LNK1000: Internal error during IncrBuildImage 1> Version 9.00.21022.08 1> ExceptionCode = C0000005 1> ExceptionFlags = 00000000 1> ExceptionAddress = ...
Hi everyone, I can't figure out how to display something (like hello world) in every 3 seconds. I'm writing in only C programming with gcc compiler in linux. We can stop it by Ctrl+c. I just want simplest and easiest way to manipulate thet code with my project. Thank you so much in advance! ...
I have created a macro to make reserve memory for my strings in C. It looks like this: #define newString(size) (char*)malloc(sizeof(char) + size) So is there any reason I shouldn't use this macro in my own personal projects? I know I shouldn't do this in production code because it would require everyone to have that header file and ev...