c99

Apparently the following function prototypes are valid in C99 and C11: void foo(int a[const *]); void bar(int a[static volatile 10]); What is the purpose of those strange subscript notations * , static , and CV qualifiers? Do they help distinguish statically typed arrays from variable-length arrays? Or are they just syntactic sugar? static in parameter array declarator void f(int a[static 10]); static here is an indication that parameter a is a pointer to int but that the array objet (where a is a pointer to its first element) has at least 10 elements. A compiler has then the right to assume f

How do I printf long long int and also unsigned long long int in C99 using GCC? I have searched the other posts which suggest to use %lld but it gives these warnings: warning#1: unknown conversion type character 'l' in format [-Wformat]| warning#2: too many arguments for format [-Wformat-extra-args]| For the following attempt: #include <stdio.h> int main() { long long int x = 0; unsigned long long int y = 0; printf("%lld\n", x); printf("%llu\n", y); } nos If you are on windows and using mingw, gcc uses the win32 runtime, where printf needs %I64d for a 64 bit integer. (and %I64u for an unsinged

I, and I think many others, have had great success using smart pointers to wrap up unsafe memory operations in C++, using things like RAII, et cetera. However, wrapping memory management is easier to implement when you have destructors, classes, operator overloading, et cetera. For someone writing in raw C99, where could you point (no pun intended) to help with safe memory management? Thanks. The question is a bit old, but I figured I would take the time to link to my smart pointer library for GNU compilers (GCC, Clang, ICC, MinGW, ...). This implementation relies on the cleanup variable

This is inspired by this question and the comments on one particular answer in that I learnt that strncpy is not a very safe string handling function in C and that it pads zeros, until it reaches n , something I was unaware of. Specifically, to quote R.. strncpy does not null-terminate, and does null-pad the whole remainder of the destination buffer, which is a huge waste of time. You can work around the former by adding your own null padding, but not the latter. It was never intended for use as a "safe string handling" function, but for working with fixed-size fields in Unix directory tables

Is a C compiler allowed to add functions to standard headers and still conform to the C standard? I read this somewhere, but I can't find any reference in the standard, except in annex J.5: The inclusion of any extension that may cause a strictly conforming program to become invalid renders an implementation nonconforming. Examples of such extensions are new keywords, extra library functions declared in standard headers , or predefined macros with names that do not begin with an underscore. However, Annex J is informative and not normative... so it isn't helping. So I wonder if it is okay or