I use Windows and codeblocks 13.12 IDE. I'm writing a C program need functions in <Winsock2.h> (like "WSAStartup" function) ; because Logs showed "Undefined Reference to WSAStartup", I included the command below according to the article WSAStartup link error.
#include <stdio.h>
#include <Winsock2.h>
#pragma comment(lib,"ws2_32.lib")
in case compiling process went wrong while linking library, I had put my program in a project and added "ws2_32.lib" into list of "Link libraries"; however, Logs only shows "cannot find -lws2_32.lib" I'm confused because I have checked that "ws2_32.dll" file exists in my C:\Windows\System32. How should I resolve the problem?
Related
I am trying to use VSCode for writing and executing C codes for a course in Windows 10. I installed VSCode and MinGW as the instructions said. I'm trying to run a simple code (print "Hello world"), but when I run the code, the output says "Access denied"
//Test code for C in Windows 10
#include "stdio.h"
#include "stdlib.h"
void main(){
printf("Hello world");
}
I'm not sure if it's gonna solve your problem but when you include header from LibC or any different lib you must use this syntax
#include <stdio.h>
#include <stdlib.h>
If you use < symbol, the preprocessor will look in special path defined by your environement else if you use " symbol, the preprocessor will look in your current directory,
I have visual studio installed in my system. So its corresponding compiler and environment variables are set. When i try to compile c file using cl command, it works fine. Now i zipped mingW from another system and extracted it to my system. Say i have it in D:/mingW. Now i have created a batch file for compiling the c file. The contents of the batch file are,
set gccPath=D:/mingW/bin
%gccPath%/gcc.exe -c -std=c99 -o myC.o ../myC.c -I..\.
When i run this batch file, it is producing few errors.
One such error is
stdio.h:209:71: error: macro "snprintf" requires 5 arguments, but only 4 given
The above error might be due to the fact that compiler takes the stdio.h of visual studio instead of mingW's default header file.
Another error is,
error: previous declaration of 'xxxxFun' was here
What should i change in the batch script to compile the c file completely using mingW.
Compilation process is successful when we use Visual Studio, but throws error if we use gcc for the same set of files
EDIT:
I fixed the latter error.
Also the first error doesn't occur when stdio.h is included at first. But if we include stdio.h at the middle of the include section, the error comes.
#include <string.h>
#include <assert.h>
#include <minmax.h>
#include "myFunctions.h"
#include "MyModule.h"
#include <stdio.h>
When we have stdio.h at last as shown, the error is coming. If we move the line #include <stdio.h> to any other lines above #include <MyModule.h> , the specified error is not coming. Any reason behind this strange behavior?
Check whether you are defining snprintf using macros in any of your header files. This error may be caused due to incorrect/unnecessary macro.
I am trying to compile a simple C program using TUrbo C++ 3.2. But getting the following error: Unable to open include file 'STDIO.h'
I do have these files in INCLUDE library.
Cant help you if you dont post your code. Check if you use #include <cstdio> (not #include "cstdio" or #include <cstdio.h> or #include "cstdio.h".
#include <cstdio> will always work.
I am using code::blocks IDE which runs on GNU GCC compiler. In my project I want to play a .wav sound file in C. I tried to play a .wav sound file with a function called PlaySound. When I compiled the code code::blocks gave me an error - PlaySoundA not declared. My code is-
#include <stdio.h>
#include <windows.h>
#include <windowsx.h>
#include <mmsystem.h>
int main(int argc, char *argv[])
{
PlaySound("C:\Snakes and Ladders\snake.wav",NULL,SND_SYNC | SND_LOOP | SND_FILENAME);
return 0;
}
I checked my path twice. I read about this function on the internet and as per me I am using it in the correct way.
In Google, I read that the function exists in a file called winmm.lib. So I put a line of code after all the headers. It was-
#pragma comment (lib , "winmm.lib")
I also added the name winmm.lib to the additional dependencies of code::blocks. So now when I compile the code it gives me another error - winmm.lib not found. Can somebody please tell me how to use PlaySound correctly.
Remove the pragma comment
Double the backslashes. The backslash is an escape character
Compile with the winmm library. Using MinGW, the command would look like this:
gcc foo.c -o foo.exe -lwinmm
Go to Settings - compiler... - linker settings. on the right side in other linker option write this:-lwinmm
I recently started SDL2.0 programming.
I did a lot of researches and i tried all but i still get those "undefined reference" errors for all the SDL functions:
undefined reference to `SDL_Init'|
undefined reference to `SDL_GetError'|
undefined reference to `SDL_Quit'|
||=== Build finished: 3 errors, 0 warnings ===|
on that simple test program:
#include <stdlib.h>
#include <stdio.h>
#include "SDL.h"
int main(int argc, char* argv[])
{
if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER) != 0) {
fprintf(stderr, "\nUnable to initialize SDL: %s\n", SDL_GetError());
return 1;
}
atexit(SDL_Quit);
return 0;
}
If i have to guess the problem occurs due to the wrong command line syntax.
In this case what should be the correct one?
You aren't linking to the SDL libraries correctly.
Add the following lines int Other Linker Option
-lSDL -lSDLmain
mingw32
SDLmain
SDL
Also You need to check setup for how to compile SDL in codeblock
http://wiki.codeblocks.org/index.php?title=Using_SDL_with_Code::Blocks
http://lazyfoo.net/SDL_tutorials/lesson01/windows/codeblocks/
If it's not too late then try from the beginging to how to set up SDL in codeblock and successfully run it? Below link provide you exact steps for it.
http://www.dreamincode.net/forums/topic/57275-setting-up-codeblocks-to-work-with-sdl/
You might have not linked SDL2 correctly to your CodeBlocks project and not referred to SDL2 correctly in your code.
1:
Go to "Linker options" in "Build Options" menu and make sure you have added these library's to your project like this:
Library's to include in linker options
Importent!: save project before running it after adding/changeing library's.
2:
Change:
#include "SDL.h"
to this:
#include <SDL2/SDL.h>
if you still encounter problems compiling and running it, it's most likely either, your SDL2 files not placed correctly in the compiler's folders, or your using an version of gcc with some missing tools.
These Youtube video's explain everything in great detail:
1: https://www.youtube.com/watch?v=x0LUf7Ibpi0
2: https://www.youtube.com/watch?v=EtUw_7CvRRo