I am running just a little code using libsndfile, in the emscripten environment
#include <iostream>
#include <sndfile.h>
int main()
{
SF_INFO info;
const char * path = "~/data/somefile.wav";
SNDFILE* sf = sf_open(path,SFM_READ, &info);
if(sf == NULL)
{
std::cout<< sf_strerror(sf) << std::endl;
return 1;
}
std::cout<<info.samplerate<<std::endl;
std::cout<<"Hello world" << std::endl;
}
So ideally if I run this with normal cmake (Apple Clang compiler) everything works fine, the samplerate and hello world are printed, but when I run this with emcmake cmake (em++ compiler) and run the compiled node main.js file it says System error: no such file or directory. Who can help me with this? Who has experienced such thing?
So I figured it out.
The problem is that Emscripten has its virtual file environment. So if you want this file to be uploaded and later be seen in compiled .js file, you need to add compile flag --preload-file <FILE_PATH> , after that the file with given path will be recognized by emscripten environment.
Related
I am working on Windows and I am trying to write an array into a Ubuntu device using C++ in Visual Studio 2019. Here's a sample of my code:
int Run_WriteCalibTable(char *pcIPAddress, int iNumArgs, float *fArgs, int *iAnsSize, char *sAns)
...
...
...
char pcFolderName[256];
char pcFileName[256];
sprintf(pcFolderName, "%s\\%s",pcSavePath, pcUUTSerialNumber);
sprintf(pcFileName, "%s\\calib_rfclock.conf",pcFolderName);
// WRITE TABLE ON PC
FILE *pFileW;
pFileW = fopen(pcFileName,"wb");
fwrite(&CalibTable, sizeof(char), CalibTable.hdr.v1.u32Len, pFileW);
fclose(pFileW);
}
return 0;
However, I keep having this pop-up from Microsoft Visual C++ Debug Library that says:
Debug Assertion Failed:
Program:...
File: f:\dd\vctools\crt_bld\sefl_x86\crt\src\fwrite.c
Line: 77
Expression: (stream != NULL)
...
I found this thread and I tried logging in as root on my Ubuntu device. I also tried:
mount -o remount,rw /path/to/parent/directory
chmod 777 /path/to/parent/directory
And I can also create/edit manualy any file in the directory I'm trying to write into with my code, but I get the same error when running it.
Anyone knows what could cause this? I think it could be on the Windows side, but I don't know what I am doing wrong. Thanks a lot in advance.
You never check that opening the file succeeds - and it most likely fails, which is why you get the debug pop-up. Your use of \ as directory delimiters may be the only reason why it fails, but you should check to be sure.
I suggest that you use std::filesystem::path (C++17) to build your paths. That makes it easy to create paths in a portable way. You could also make use of a C++ standard std::ofstream to create the file. That way you don't need to close it afterwards. It closes automatically when it goes out of scope.
Example:
#include <cerrno>
#include <cstring>
#include <filesystem>
#include <fstream>
int Run_WriteCalibTable(char *pcIPAddress, int iNumArgs, float *fArgs,
int *iAnsSize, char *sAns)
{
...
// Build std::filesystem::paths:
auto pcFolderName = std::filesystem::path(pcSavePath) / pcUUTSerialNumber;
auto pcFileName = pcFolderName / "calib_rfclock.conf";
// only try to write to the file if opening the file succeeds:
if(std::ofstream pFileW(pcFileName, std::ios::binary); pFileW) {
// Successfully opened the file, now write to it:
pFileW.write(reinterpret_cast<const char*>(&CalibTable),
CalibTable.hdr.v1.u32Len);
} else {
// Opening the file failed, print the reason:
std::cerr << pcFileName << ": " << std::strerror(errno) << std::endl;
}
...
}
I have a cpp program that uses fopen_s to open and read a file created under the directory C:\Windows\System32\config\systemprofile\AppData\Roaming.
My program needs to be compatible with winx64 and win32.
When I run this program with a system account (run using PSTools\PSExec -i -s C:\windows\system32\cmd.exe) and the Win32 compiled version of the program, fopen_s() on any file inside "C:\Windows\System32\config\systemprofile\AppData\Roaming" returns an error code 2, even though the file is present.
However, when I run the x64 compiled version of the same program, it works fine and fopen_s() is able to find and open the same file.
I am sure there are no mistakes as far as passing a valid filename to fopen_s() and I have verified this.
I make sure that the int variable that stores the return value from fopen_s() is set to 0 every time before calling fopen_s(). I am calling fopen_s() in "r" mode.
Also, elsewhere in the same program I am able to create files under the same directory.
I am using VS2019 and cpp +11 to compile my program.
My system is running windows 10 (64-bit) on an x64 processor (Intel(R) Xeon(R) Gold 6136)
Why would a win32 application fail to read a file created under "C:\Windows\System32\config\systemprofile\AppData\Roaming" with a system account while the x64 version of the same application works fine?
Code snippet:
int FileOpenFunc(FILE ** ppFile, std::string sFilename, std::string sOpenMode)
{
int errOpen = 0;
#ifdef _WIN32
errOpen = fopen_s(ppFile, sFilename.c_str(), sOpenMode.c_str());
#else
*ppFile = fopen(sFilename.c_str(), sOpenMode.c_str());
errOpen = errno;
#endif
return errOpen;
}
void func()
{
std::string sFileName = "C:\\Windows\\System32\\config\\systemprofile\\AppData\\Roaming\\Check\\sample.txt";
int errFopenErrNo = 0;
FILE* fp = NULL;
errFopenErrNo = FileOpenFunc(&fp, sFileName, "r");
if (fp!= NULL)
{
//do something
}
else
{
//do something else
}
}
I am trying to run this simple example in GDCM. I have installed the library c++ version and the installation works perfectly fine but I am not able to figure out how to compile and run a example.
#include "gdcmReader.h"
#include "gdcmWriter.h"
#include "gdcmAttribute.h"
#include <iostream>
int main(int argc, char *argv[])
{
if( argc < 3 )
{
std::cerr << argv[0] << " input.dcm output.dcm" << std::endl;
return 1;
}
const char *filename = argv[1];
const char *outfilename = argv[2];
// Instanciate the reader:
gdcm::Reader reader;
reader.SetFileName( filename );
if( !reader.Read() )
{
std::cerr << "Could not read: " << filename << std::endl;
return 1;
}
// If we reach here, we know for sure only 1 thing:
// It is a valid DICOM file (potentially an old ACR-NEMA 1.0/2.0 file)
// (Maybe, it's NOT a Dicom image -could be a DICOMDIR, a RTSTRUCT, etc-)
// The output of gdcm::Reader is a gdcm::File
gdcm::File &file = reader.GetFile();
// the dataset is the the set of element we are interested in:
gdcm::DataSet &ds = file.GetDataSet();
// Contruct a static(*) type for Image Comments :
gdcm::Attribute<0x0020,0x4000> imagecomments;
imagecomments.SetValue( "Hello, World !" );
// Now replace the Image Comments from the dataset with our:
ds.Replace( imagecomments.GetAsDataElement() );
// Write the modified DataSet back to disk
gdcm::Writer writer;
writer.CheckFileMetaInformationOff(); // Do not attempt to reconstruct the file meta to preserve the file
// as close to the original as possible.
writer.SetFileName( outfilename );
writer.SetFile( file );
if( !writer.Write() )
{
std::cerr << "Could not write: " << outfilename << std::endl;
return 1;
}
return 0;
}
/*
* (*) static type, means that extra DICOM information VR & VM are computed at compilation time.
* The compiler is deducing those values from the template arguments of the class.
*/
It has a few header files that it is looking for namely gdcmreader, gdcmwriter and I want to figure out the compiler flags to use to be able to run this file.
I am doing g++ a.cpp -lgdcmCommon -lgdcmDICT but that gives me the error
a.cpp:18:24: fatal error: gdcmReader.h: No such file or directory
compilation terminated.
Can you please help me out? I have searched everywhere but I can't seem to figure out how to run this file.
When using files that are in different locations of your "normal" files you must instruct the compiler and the linker how to find them.
Your code has a #include <someFile.h> command.
The <> usage means "in other path". The compiler already knows common "other paths" as for "stdio" for common libraries.
In case of "not normal", you can tell g++ where to find the headers by adding -Imydir to the command line (replace 'mydir' with the proper path)
For the libraries, static (.a) or dynamic (.so) the same history stands.
The -Lmydir tells g++ where to look for libraries.
Your command line may look like
g++ a.cpp -I/usr/include -L/usr/local/lib -lgdcmCommon -lgdcmDICT
You did not tell how did you install gdcm library, I assume that using apt system. There are two types of libraries, "normal" and "developer" ones. To be able to compile your own software, you need the latter. So, for example in Ubuntu 16.04, type apt-get install libgdcm2-dev. Then all necessary headers will be installed in /usr/include/gdcm-2.6.
Im using the latest SDL 2.0 version on Xubuntu 64-bits. I installed through the provided install script on the source code.
Compiling works well, however when trying to open a font or image (regardless of its extension), it will always fail to open.
#include <iostream>
#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>
int main (int argc, char *argvp[])
{
if (SDL_Init(SDL_INIT_EVERYTHING) == -1)
{
cout << SDL_GetError() << endl;
}
if (TTF_Init() == -1)
{
std::cout << TTF_GetError() << std::endl;
return 2;
}
TTF_Font *font1 = NULL;
font1 = TTF_OpenFont("SourceSansPro-Regular.ttf", 20);
if (font1 == NULL)
{
std::cout << "ERROR OPENING FONT = " << TTF_GetError() << std::endl;
}
TTF_CloseFont(font1);
SDL_Quit();
return 0;
}
I compiled with
g++ -Wall fontTEST.cpp -o TEST -lSDL2 -lSDL_ttf (NOTE that SDL_ttf installs as such, not as SDL2_ttf)
And get the following error: Failed to load font: 0 Couldn't load font file
This happens with images as well. I've already tried with different fonts and images, apparently it works if I compile with SDL 1.2, just not with 2.0.
Also why does the provided install script installs the lib and include folders in /user/local/?
I moved them to /usr/ but the problem persists.
Remember the following:
On Unix, file paths are case-sensitive
As said in Xonar's comment, tilde '~' expansion is a shell feature, it does not work in C/C++ programs, you should use the real path instead.
The strace log says clearly that something is wrong with the path.
You should try the following:
Rename your font file to "font.ttf"
put it in /home/user/font.ttf
use "/home/user/font.ttf" as the path in your code.
This is the code I have for checking if a file exists in my visual studio 2010 c++ project:
bool GLSLProgram::fileExists( const string & fileName )
{
struct stat info;
int ret = -1;
ret = stat(fileName.c_str(), &info);
return 0 == ret;
}
I am not sure why it returns false for "shaders/color.vert" when that file really exists, and shaders is a folder in my project main folder.
Can you see something wrong?
THanks
Ok, so to illustrate the quirks of running from the IDE here's a little test I did. Hopefully this should help you figure out how relative paths work in VS.
So my folder hierarchy looks like this:
/_Sandbox
_Sandbox.sln
/Debug
_Sandbox.exe
/shaders
color.vert
/_Sandbox
_Sandbox.proj
main.cpp
The code looks as follows:
#include <iostream>
#include <string>
#include <sys/stat.h>
int main(int argc, char* argv[])
{
struct stat info;
std::string path = "shaders/color.vert"; // To not I get the same behavior with "shaders\\color.vert"
int ret = stat(path.c_str(), &info);
ret == 0 ? std::cout << "File found." << std::endl : std::cout << "File doesn't exist." << std::endl;
std::cin.get();
return 0;
}
So if I run this in the IDE, I get "File doesn't exist.", if I run this outside the IDE, I get "File Found". In order for the program to find the shader file from inside VS I have to put the shader folder like so:
/_Sandbox
_Sandbox.sln
/Debug
_Sandbox.exe
/_Sandbox
/shaders
color.vert
_Sandbox.proj
main.cpp
You can however get the code to find the folder from inside and outside the IDE. What you have to do is go to your project's settings. In "Debugging" and change "Working directory" to $(SolutionDir)$(Configuration)\
Hopefully this clears things up for you.