Comment by Zan Lynx on How Do You Programmatically Set the Hardware Clock on...
@Offler This answer was not meant as a copy and paste ready to use solution. I included the struct to show how it worked. For a real example view the source code to the hwclock program.
View ArticleComment by Zan Lynx on How can I solve race condition for Golang WAF service?
In case you haven't found it yet, look for the Go race detector. Very handy. I believe it is the -race flag when building.
View ArticleComment by Zan Lynx on GCC issues a warning that my precompiled headers...
Macro definitions must be IDENTICAL. So defining your PCH define is not going to work. And it looks like your rule to produce the gch file is producing assembler output. That won't work, ever. And I...
View ArticleComment by Zan Lynx on Why this code gives run time error on mid calculation?
A tip for code formatting. Copy it from your IDE or text editor and paste it into Stack Overflow. Then select all the code and click the format button for "Code" which will add the four spaces in front...
View ArticleComment by Zan Lynx on How to create a collection of member variables at...
@jhnlmn You already have a thing that collects mutable variables of different types with descriptive names. It is a struct. It's called a struct.
View ArticleComment by Zan Lynx on Using read() for reading a file in C
@GratefullyDead "the snippet here that really matters" No. If you do not understand what is going on, and you obviously don't, then you don't know what really matters. Sometimes the particular header...
View ArticleComment by Zan Lynx on Why do I need a C++ redistributable for a specific IDE?
Oh yeah you may also look into using support.microsoft.com/en-us/topic/… aka the Universal C Runtime.
View ArticleComment by Zan Lynx on Why do I need a C++ redistributable for a specific IDE?
@Joe If you pick Visual Studio 17's C++ compiler then you need the DLL for 17. Otherwise it won't have support for the updated versions of C++ std::string and other things. I also tried to show how you...
View ArticleComment by Zan Lynx on Function signature for potentially failed unique_ptr...
@МоргуновВладислав: Only if I change the parameter to remove the &&. Then it works. Updating.
View ArticleComment by Zan Lynx on How to use sched_yield() properly?
On Linux sched_yield with SCHED_OTHER (ie normal processes) is not a good thing to use. It puts the thread at the very end of all process and thread priorities. Not just the threads in the process....
View ArticleComment by Zan Lynx on C++ pthread hand over object to thread
Ever since C++11 which is now ten years old, there has been no reason to use pthreads directly in C++.
View ArticleAnswer by Zan Lynx for C++ expected unqualified id
I believe the error is caused because you didn't #include <string>.But there are other problems too. It sort of looks like you meant to create a send function but the semicolon ; is causing it to...
View ArticleAnswer by Zan Lynx for Dropping C library on Linux w/GCC
Here is what I got:#include <sys/syscall.h>// Copied from MUSL libc// There are more at// http://git.musl-libc.org/cgit/musl/tree/arch/x86_64/syscall_arch.hstatic __inline long __syscall1(long n,...
View ArticleAnswer by Zan Lynx for Why this simple C program uses has different cpu usage...
There are a couple of things that can cause this.First, programs that monitor CPU usage report in different ways. Windows Task Manager reports 50% for one entire CPU core at maximum use. Apple's...
View ArticleAnswer by Zan Lynx for Is the memory allocation done by malloc always...
A single block of memory returned by malloc, calloc or realloc will always be contiguous.The next block of memory returned by a separate alloc call can be at any address and does not need to be...
View ArticleAnswer by Zan Lynx for Is there a C++ function to suspend of resume a child...
You said Powershell in the tags so I assume Windows.If you have a handle to a process then you can do things to that process. The list of things you can do is documented in MSDN. In this case you would...
View ArticleAnswer by Zan Lynx for How to cout int like a double
You are supposed to do it with the locale library.Mostly copied from https://en.cppreference.com/w/cpp/io/manip/put_money like so:#include <iomanip>#include <iostream>#include...
View ArticleAnswer by Zan Lynx for at job scheduler doesn't work on my Ubuntu
PyCharm and other GUI programs need a lot of information from your environment. The atd daemon which runs jobs for at does not have access to this environment. You will need to specify it directly.I...
View ArticleAnswer by Zan Lynx for How Do I run a certain .cpp file in Visual studio?
If you want to run certain functions in order to see if they're working properly, that is a good thing and is called Unit Testing.You want to look into the C++ unit testing features of Visual...
View ArticleAnswer by Zan Lynx for Do all functions in a c++ program's main function get...
An uncaught C++ exception will terminate the program. Often with a stack trace but that is up to the implementation.So no, in your example bar() will never be called.Update: In some situations the...
View ArticleAnswer by Zan Lynx for C++: expected ';' at end of member declaration
Here is how your code should look. clang-format fixed it up.#include <iostream>#include <string>using namespace std;class employee {protected: string name; string surname; int tel; int...
View ArticleAnswer by Zan Lynx for Memory leak in golang slices of slices
Every slice points to a backing array. The Go garbage collector does not look at the active slices. It only looks at the pointers that exist in allocated memory, which would be the entire array even if...
View ArticleAnswer by Zan Lynx for getline(file, text) exhibits strange behavior : stuck...
Obviously, your program is not running from the directory you think it is.Visual Studio is particularly bad about this, I find. You'll need to go into the Properties for the project and see where the...
View ArticleAnswer by Zan Lynx for Is it a necessary trade-off that using smart pointers...
Your static member function, or friend function, which is the factory should have no problem with calling protected constructors and returning a smart pointer. Generally plan to return a...
View ArticleAnswer by Zan Lynx for Freeing heap on exit in C automatically
First I should point out that doing this is kind of useless because as others have said the operating system is going to clean all of your program out of memory on exit.But anyway.Have some fun with...
View ArticleAnswer by Zan Lynx for Using vector::data() chaining with member function...
You returned a temporary copy of your vector. After the statement it is part of it is destroyed. If you wanted to keep it around you need to assign it to another vector.So, you made a pointer to a...
View ArticleAnswer by Zan Lynx for Does C have an equivalent to var?
Scripting languages which are written in C manage to implement this for their variables. However, it is quite complicated.C needs to know the size of things, so that it can place them into memory...
View ArticleAnswer by Zan Lynx for LINUX BASH SET ECHO
In the bash shell, set is used to control the numbered variables like $0, $1, etc. and shell option settings.For other shell variables you just set them. Like this:character=(a b c d e f g)echo...
View ArticleAnswer by Zan Lynx for Why this code gives run time error on mid calculation?
Because any return from main that is not 0 indicates a runtime error.
View ArticleAnswer by Zan Lynx for What does "!$@" mean in Perl?
It sort of looks like a cartoon dialogue curse word doesn't it?Take it one symbol at a time. The ! is boolean NOT, so if the following value is True it will become False, and vice versa.The $ starts a...
View ArticleAnswer by Zan Lynx for Is it possible to use epoll to write fifo/pipe data to...
I believe that the only way to solve your problem is to include a timer based polling loop where you attempt to open each FIFO once a second or so. Make that part of your select/poll/epoll loop. You...
View ArticleAnswer by Zan Lynx for why, I'm getting some strange garbage values?
Files are in bytes. Integers are made of either 4 (32-bit) or 8 (64-bit) bytes. They can also be in little-endian (Intel) or big-endian (PowerPC) byte order.In memory and in the disk file you wrote,...
View ArticleAnswer by Zan Lynx for Thread local storage processes
If you intend to write C++ and you do not have a need to use Win32 functions specifically, then you should use the C++11 thread_local. See https://en.cppreference.com/w/cpp/keyword/thread_localThis is...
View ArticleAnswer by Zan Lynx for C using fread to read an unknown amount of data
Depending on how clever you need to be with the number conversion... If you do not need to be especially clever and fast, you can read it a character at a time with getc(). So,- start with a variable...
View ArticleAnswer by Zan Lynx for Implicit function declarations in C
Because of historical reasons going back to the very first version of C, it passes whatever type the argument is. So it could be an int or a double or a char*. Without a prototype, the compiler will...
View ArticleTake the address of a one-past-the-end array element via subscript: legal by...
I have seen it asserted several times now that the following code is not allowed by the C++ Standard:int array[5];int *array_begin = &array[0];int *array_end = &array[5];Is &array[5] legal...
View ArticleHow to use Linux hugetlbfs for shared memory maps of files?
I have a program which uses mmap() and shared memory to efficiently access a large database file. I would like to experiment with huge pages to see if it speeds things up.I thought that a quick and...
View ArticleIs the compiler able to optimize try/catch into a simple goto?
It seems to me that if you have some C++ code like this:int f(){ try { if( do_it() != success ) { throw do_it_failure(); } } catch( const std::exception &e ) { show_error( e.what() ); }}The C++...
View ArticleHow to locate a thread's stack base from a core file?
I have a core dump that shows a thread dying from a SIGBUS signal while executing mov %r15d,0xa0(%rsp). That seems to tell me that it died because it ran out of thread stack.But how can I prove it? I...
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