c99

Nearly every (relatively) new book about c programming I've seen doesn't seem to adhere to the C99 standard, or they cover it in an extra chapter. Comming from a Java background, the C99 standard made the migration (well, still migrating ^^) much easier for me, and this probably applies to other languages, too. It seems like C99 hasn't reached most of the C developers yet. But why? Short answer: compiler support is slow to get installed and c programmers are a conservative lot who change their behavior slowly. I strongly suspect it's mainly because MSVC does not attempt to support C99, and

It turns out that we can prevent appearing of a zombie process (i.e. the one whose parent doesn't wait() for it to _exit() ) by specifying SIGCHLD signal to be ignored with sigaction() by its parent. However, it seems like SIGCHLD is ignored by default anyway. How come does this work? int main (void) { struct sigaction sa; sa.sa_handler = SIG_IGN; //handle signal by ignoring sigemptyset(&sa.sa_mask); sa.sa_flags = 0; if (sigaction(SIGCHLD, &sa, 0) == -1) { perror(0); exit(1); } int pid = fork(); if (pid == 0) { //child process _exit(0); } do_something(); //parent process return 0; } Barmar The

I find out about Variable Length Array in C99, but it looks like it behave almost the same as malloc + free. The practical differences I found: Too big array handling: unsigned size = 4000000000; int* ptr = malloc(size); // ptr is 0, program doesn't crash int array[size]; // segmentation fault, program crashes Memory leaks: only possible in dynamic array allocation: int* ptr = malloc(size); ... if(...) return; ... free(ptr); Life of object and possibility to return from function: dynamically allocated array lives until the memory is frees and can be returned from function which allocated the