I am building an application and I need to get the HDD size:
I am working on Mac OS. I have tried this:
#include <sys/param.h>
#include <sys/mount.h>
float MonitoringWorker::getHDDSize()
{
struct statfs statf;
statfs(".", &statf);
std::cout << "statf.f_bsize = " << statf.f_bsize << std::endl;
std::cout << "statf.f_blocks = " << statf.f_blocks << std::endl;
std::cout << "statf.f_bavail = " << statf.f_bavail << std::endl;
std::cout << "statf.f_bfree = "<< statf.f_bfree << std::endl;
std::cout << "GB = "<< ((statf.f_bsize * statf.f_blocks) / kBytesInGB)<< std::endl;
return 0;
}
I am seeing that the result in GB is 465. However checking System Information tells me that I have 500GB
What am I doing wrong? Is this best way to get those numbers?
Note: I am using C++ on Mac OS, can't use Objective-C
Thanks in advance
Related
I am trying to get the exit code of a child process (using boost::process and boost::asio) when that child process is killed due to a segmentation violation or divide be zero or any other kill signal. The exit code and error code always return with 0 and success.
I am running this on CentOS 7 using g++ 4.8.5 and boost 1.66
If I run the same code with a child process that simply returns a non-zero exit code it successfully returns that exit code.
#include <iostream>
#include <boost/process.hpp>
#include <boost/asio/io_service.hpp>
namespace bp = boost::process;
using namespace std;
int main (int argc, char** argv)
{
string exe = "./crashes";
vector<string> data;
boost::asio::io_service ios;
int exit_code;
error_code ec;
future<string> ostr;
bp::child c(exe,
(bp::std_out & bp::std_err) > ostr,
ios,
bp::on_exit=[&exit_code, &ec](int exit, const error_code& ecin)
{exit_code = exit; ec = ecin;});
ios.run();
cout << "Exit Code = " << exit_code << endl;
cout << "Error Code = " << ec.message() << endl;
cout << "child stdin & stderr:\n";
cout << ostr.get() << endl;
return exit_code;
}
and the crashes code
int main (int argc, char** argv)
{
int* y = 0;
int c = *y;
}
The results show a 0 exit code and Success error_code
Exit Code = 0
Error Code = Success
child stdin & stderr:
running the crashes executable alone returns an exit code of 139
bash-4.2$ ./crashes
Segmentation fault (core dumped)
bash-4.2$ echo $?
139
The details of process termination and exit codes are platform dependent.
Boost process papers over the differences in the default interface: your on_exit handler is called with the result of boost::process::detail::posix::eval_exit_status() of the exit status, which means:
inline int eval_exit_status(int code)
{
if (WIFEXITED(code))
{
return WEXITSTATUS(code);
}
else if (WIFSIGNALED(code))
{
return WTERMSIG(code);
}
else
{
return code;
}
}
So, you get "exit-code 11" meaning segfault... If you want to actually know, you can look at native_exit_code()
bp::on_exit = [&result, &c](int /*ignored*/, const std::error_code &ec) {
auto exit_status = c.native_exit_code();
result.exit_code = boost::make_optional(WIFEXITED(exit_status), WEXITSTATUS(exit_status));
result.signal = boost::make_optional(WIFSIGNALED(exit_status), WTERMSIG(exit_status));
result.ec = ec;
}
Now this assumes some changes to the result variables. Full listing:
Listing
#include <boost/asio/io_service.hpp>
#include <boost/process.hpp>
#include <iostream>
namespace bp = boost::process;
int main(int argc, char**) {
std::string exe = argc>1? "./ltua" : "./crashes";
boost::asio::io_service ios;
struct {
boost::optional<int> exit_code;
boost::optional<int> signal;
std::error_code ec{};
} result;
std::future<std::string> ostr;
bp::group g;
bp::child c(exe, g, (bp::std_out & bp::std_err) > ostr, ios,
bp::on_exit = [&result, &c](int /*ignored*/, const std::error_code &ec) {
auto exit_status = c.native_exit_code();
result.exit_code = boost::make_optional(WIFEXITED(exit_status), WEXITSTATUS(exit_status));
result.signal = boost::make_optional(WIFSIGNALED(exit_status), WTERMSIG(exit_status));
result.ec = ec;
});
//g.wait();
ios.run();
if (result.exit_code) {
std::cout << "Exited with " << *result.exit_code << std::endl;
}
if (result.signal) {
std::cout << "Signaled with sginal #" << *result.signal << ", aka " << ::strsignal(*result.signal) << std::endl;
}
std::cout << "Error Code = " << result.ec.message() << std::endl;
std::cout << "child stdin & stderr:\n";
std::cout << ostr.get() << std::endl;
return result.exit_code? *result.exit_code : 255;
}
Output
When run with ltua.cpp:
#include <iostream>
int main() {
std::cout << "so long" << std::end;
std::cerr << "and thanks" << std::end;
std::cout << "for all" << std::end;
std::cerr << "the fish" << std::end;
return 42;
}
Prints
Exited with 42
Error Code = Success
child stdin & stderr:
so long
and thanks
for all
the fish
And with crashes.cpp:
int main() {
int *y = 0;
int c = *y;
}
Prints
Signaled with sginal #11, aka Segmentation fault
Error Code = Success
child stdin & stderr:
I need to create a hyper link in my comments section of my c++ code so that , when I click on the link, it should take me to a specific line of the same code base.
That specific line could be in same file or different, but of course the same project.
Is this possible in Visual studio when writing c/c++ code.
For example,
int main()
{
Marks m1(10,20);
Marks m2(30,40);
Marks m3,m4;
//Line 7
std::cout <<m1.get_int_marks()<<std::endl;
std::cout << m1.get_ext_marks() << std::endl;
m3 = m1 + m2;
//Line 14
std::cout << m3.get_int_marks() << std::endl;
std::cout << m3.get_ext_marks() << std::endl;
m4 = m1 - m2;
int x = 10 + 20;
std::cout << m4.get_int_marks() << std::endl;
std::cout << m4.get_ext_marks() << std::endl;
std::cout << x << std::endl;
return 0;
}
In the above code , can I create a hyperlink in the comments, at line 7 to go to line 14.
Used case can be to go to any line of any file in the project.
Thanks in advance.
In case you want a link to method, you can use empty function macro to prevent compiler warnings, privates, etc.
Put pseudo code inside and follow by F12 (Visual Studio) or similar key elsewhere.
Includes are often mandatory for jump to wanted method directly.
#define CALLERS(...)
#include "myClass.h"
#include "myFunctions.h"
CALLERS(myClass::myMethod; function();)
Using this msdn reference I created a small use case.
#include <iostream>
#include <windows.h>
int main()
{
const std::wstring dir_path = L"\\\\?\\c:\\temp\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory\\ThisIsPrettyLongNameForDirectory";
if (!CreateDirectoryW(dir_path.c_str(), NULL))
{
std::cout << " Error occurred while creation of directory!!! " << GetLastError() << std::endl;
}
else
{
std::cout << "Lenth is " << dir_path.length() << std::endl;
if (dir_path.length() > 255)
{
if (!SetCurrentDirectoryW(buf.c_str()))
{
std::cout << " Error occurred!!! " << GetLastError() << std::endl;
}
else
{
std::cout << " Successful!!!" << std::endl;
}
}
}
return 0;
}
However, I get the output as
Error occurred while creation of directory!!! 3
Error code 3 points me to
ERROR_PATH_NOT_FOUND
3 (0x3)
The system cannot find the path specified.
Are there any other way to use long path names in CreateDirectoryW or SetCurrentDirectoryW APIs that I am unaware of ?
PS:I am using VS 2015 Update 3 compiler on Windows 7.
You have to create each directory on the path one by one. So the parent directory to the directory you pass must exist before you call CreateDirectory.
This information can be found by reading the documentation. It specifically calls out that error code and says:
One or more intermediate directories do not exist; this function will only create the final directory in the path.
I just starting to use the debug extension in my project but the glObjectLabel generates an error when used with GL_BUFFER.
Graphic card is a nVidia Quadro 600 with 340.82 drivers
This simple test is built with MSVC 2010 in 32bit :
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
void GLAPIENTRY ogl_cb(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, const void* userParam)
{
using namespace std;
cout << "message: "<< message << endl;
}
int main()
{
using namespace std;
if (!glfwInit())
{
cerr << "Error initializing GLFW" << endl;
return 1;
}
glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, GL_TRUE);
GLFWwindow *window = glfwCreateWindow(1, 1, "", NULL, NULL);
glfwMakeContextCurrent(window);
GLint glew_result = glewInit();
if (GLEW_OK != glew_result)
{
cerr << "Error initializing GLEW : " << (const char*)glewGetErrorString(glew_result) << endl;
return 2;
}
cout << "VENDOR : " << glGetString(GL_VENDOR) << endl;
cout << "RENDERER : " << glGetString(GL_RENDERER) << endl;
cout << "VERSION : " << glGetString(GL_VERSION) << endl;
cout << "GLSL VERSION : " << glGetString(GL_SHADING_LANGUAGE_VERSION) << endl;
glDebugMessageCallback(ogl_cb, NULL);
glEnable(GL_DEBUG_OUTPUT);
glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
GLuint progid = glCreateProgram();
glObjectLabel(GL_PROGRAM, progid, -1, "My program");
GLuint bufid;
glGenBuffers(1, &bufid);
glObjectLabel(GL_BUFFER, bufid, -1, "My buffer");
char prog_name[100];
GLsizei prog_name_len = 0;
glGetObjectLabel(GL_PROGRAM, progid, 100, &prog_name_len, prog_name);
cout << "Program name " << prog_name_len << " : " << (prog_name_len ? prog_name : "NULL") << endl;
char buf_name[100];
GLsizei buf_name_len = 0;
glGetObjectLabel(GL_BUFFER, bufid, 100, &buf_name_len, buf_name);
cout << "Buffer name " << buf_name_len << " : " << (buf_name_len ? buf_name : "NULL") << endl;
glfwDestroyWindow(window);
glfwTerminate();
return 0;
}
And the output on machine :
VENDOR : NVIDIA Corporation
RENDERER : Quadro 600/PCIe/SSE2
VERSION : 4.5.0 NVIDIA 340.82
GLSL VERSION : 4.50 NVIDIA
message: GL_INVALID_VALUE error generated. ObjectLabel: unknown buffer object <name>
Program name 10 : My program
message: GL_INVALID_VALUE error generated. GetObjectLabel: unknown buffer object <name>
Buffer name 0 : NULL
Everything is OK with the program, but not the buffer...
Looking at samples from www.g-truc.net, and other on the net, I just can't seem what I do wrong...
Any clue on what is going on here ?
Object you assign label to must already be created. glGenBuffers only reserves names, without creating anything. glCreateProgram, on the contrary, generates one new name and creates program object.
Binding buffer object at least once would be enough.
I'm using ReadDirectoryChangesW to monitor a directory.
Here's my simple code
#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <tchar.h>
#include <iostream>
#include <string>
#include <cwctype>
using namespace std;
wstring getname(FILE_NOTIFY_INFORMATION *tmp)
{
wstring s = L"";
for (int i = 0;i < tmp->FileNameLength / 2;i++)
s += tmp->FileName[i];
return s;
}
void _tmain(int argc, TCHAR *argv[])
{
HANDLE hDir;
char notify[1024];
DWORD cbBytes,i;
char AnsiChar[3];
wchar_t UnicodeChar[2];
LPTSTR path;
FILE_NOTIFY_INFORMATION *pnotify=(FILE_NOTIFY_INFORMATION *)notify;
FILE_NOTIFY_INFORMATION *tmp ;
// GetCurrentDirectory(MAX_PATH,path.GetBuffer(MAX_PATH+1));
wcout.imbue(locale("chs"));
path = argv[1];
hDir = CreateFile( path, FILE_LIST_DIRECTORY,
FILE_SHARE_READ |
FILE_SHARE_WRITE |
FILE_SHARE_DELETE, NULL,
OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS |
FILE_FLAG_OVERLAPPED, NULL);
wcout << L"===CreateFile complete===" << endl;
if (hDir == INVALID_HANDLE_VALUE)
{
wcout << L"invalid handle value" << endl;
return;
}
FILE_NOTIFY_INFORMATION buffer[1024];
FILE_NOTIFY_INFORMATION *pbuffer;
while (TRUE)
{
wcout << L"waiting..." << endl;
if(ReadDirectoryChangesW(hDir, &buffer, sizeof(buffer),
TRUE, FILE_NOTIFY_CHANGE_FILE_NAME| FILE_NOTIFY_CHANGE_LAST_WRITE,
&cbBytes, NULL, NULL))
{
pbuffer = buffer;
do{
tmp = pbuffer;
switch(tmp->Action)
{
case FILE_ACTION_ADDED:
wcout << L"Directory/File added - " << getname(tmp) << endl;
break;
case FILE_ACTION_REMOVED:
wcout << L"Directory/File removed - " << getname(tmp) << endl;
break;
case FILE_ACTION_MODIFIED:
wcout << L"Directory/File modfied - " << getname(tmp) << endl;
break;
case FILE_ACTION_RENAMED_OLD_NAME:
wcout << L"Directory/File old name - " << getname(tmp) << endl;
break;
case FILE_ACTION_RENAMED_NEW_NAME:
wcout << L"Directory/File new name - " << getname(tmp) << endl;
break;
default:
wcout << L"unknown action\n" << endl;
break;
}
pbuffer += pbuffer->NextEntryOffset;
}while(pbuffer->NextEntryOffset);
} else
{
wcout << "readChangesW failed now return" << endl;
return;
}
}
}
It looks fine, however, when I'm adding or deleting a large number of files in my directory, it will not report some of the changes, how can I fix this?
Try making your buffer bigger.
From the documentation for the ReadDirectoryChangesW function:
When you first call ReadDirectoryChangesW, the system allocates a buffer to store change information. This buffer is associated with the directory handle until it is closed and its size does not change during its lifetime. Directory changes that occur between calls to this function are added to the buffer and then returned with the next call. If the buffer overflows, the entire contents of the buffer are discarded and the lpBytesReturned parameter contains zero.
The buffer size that the system allocates is based on the size of the buffer you pass in. If you pass in a bigger size the system will allocate a bigger buffer to store changes that occur while you are processing the previous lot of changes, which means there's less chance of the buffer overflowing and those changes being lost.