popen equivalent in c++
You can use the “not yet official” boost.process if you want an object-oriented approach for managing the subprocess. Or you can just use popen itself, if you don’t mind the C-ness of it all.
posix
How to get the username in C/C++ in Linux?
The function getlogin_r() defined in unistd.h returns the username. See man getlogin_r for more information. Its signature is: int getlogin_r(char *buf, size_t bufsize); Needless to say, this function can just as easily be called in C or C++.
Why does SIGPIPE exist?
I don’t buy the previously-accepted answer. SIGPIPE is generated exactly when the write fails with EPIPE, not beforehand – in fact one safe way to avoid SIGPIPE without changing global signal dispositions is to temporarily mask it with pthread_sigmask, perform the write, then perform sigtimedwait (with zero timeout) to consume any pending SIGPIPE signal (which … Read more
Are POSIX’ read() and write() system calls atomic?
I don’t believe the text you cites implies anything of the sort. It doesn’t even mention read() or write() or POSIX. In fact, read() and write() cannot be relied on to be atomic. The only thing POSIX says is that write() must be atomic if the size of the write is less than PIPE_BUF bytes, … Read more
OpenMP and CPU affinity
Yes, named calls will work to set thread affinity. The only problem is to fix thread number and to set right affinity in right thread (you can try using static scheduling of for loop for known number of threads). As I know, almost every openmp allows to set affinity via environment. The name of environment … Read more
How to know if a Linux system call is restartable or not?
close is a rather special case. Not only is it not restartable on Linux; when close returns with EINTR on Linux, it has actually already succeeded, and making another call to close will fail with EBADF in single-threaded processes and cause extremely dangerous file-descriptor races in multi-threaded processes. As of the published POSIX 2008, this … Read more
Reference a GNU C (POSIX) DLL built in GCC against Cygwin, from C#/NET
The main problem which you has is following. Before you can use your helloworld.dll a cygwin environment must be initialized (see http://cygwin.com/faq/faq.programming.html#faq.programming.msvs-mingw). So the following code in native C++ will works: #include <windows.h> typedef int (*PFN_HELLO)(); typedef void (*PFN_CYGWIN_DLL_INIT)(); int main() { PFN_HELLO fnHello; HMODULE hLib, h = LoadLibrary(TEXT(“cygwin1.dll”)); PFN_CYGWIN_DLL_INIT init = (PFN_CYGWIN_DLL_INIT) GetProcAddress(h,”cygwin_dll_init”); init(); … Read more
Is Android POSIX-compatible?
GNU libc (glibc) is too big and complicated for mobile phones, so Android implements its own special version of libc which is Bionic libc, which itself does not fully support POSIX. One of the most lacking features in the android Bionic libc is pthread_cancel(), so if you don’t use it, your code will probably do … Read more
Setting creation or change timestamps
For ext2/3 and possibly for ext4 you can do this with debugfs tool, assuming you want to change the ctime of file /tmp/foo which resides in disk /dev/sda1 we want to set ctime to 201001010101 which means 01 January 2010, time 01:01: Warning: Disk must be unmounted before this operation # Update ctime debugfs -w … Read more
Differences between System V and Posix semaphores
From O’Reilly: One marked difference between the System V and POSIX semaphore implementations is that in System V you can control how much the semaphore count can be increased or decreased; whereas in POSIX, the semaphore count is increased and decreased by 1. POSIX semaphores do not allow manipulation of semaphore permissions, whereas System V … Read more