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From C, C++ inherited the convention of using null-terminated strings that are handled by a pointer to their first element, and a library of functions that manipulate such strings. In modern standard C++, a string literal such as "hello" still denotes a NUL-terminated array of characters. [1] Using C++ classes to implement a string type offers ...
For some C compilers, an extra format specifier results in consuming a value even though there isn't one. This can allow the format string attack. Generally, for C, arguments are passed on the stack. If too few arguments are passed, then printf can read past the end of the stackframe, thus allowing an attacker to read the stack.
Most of the functions that operate on C strings are declared in the string.h header (cstring in C++), while functions that operate on C wide strings are declared in the wchar.h header (cwchar in C++). These headers also contain declarations of functions used for handling memory buffers; the name is thus something of a misnomer.
The void pointer, or void*, is supported in ANSI C and C++ as a generic pointer type. A pointer to void can store the address of any object (not function), [a] and, in C, is implicitly converted to any other object pointer type on assignment, but it must be explicitly cast if dereferenced.
Most C code can easily be made to compile correctly in C++ but there are a few differences that cause some valid C code to be invalid or behave differently in C++. For example, C allows implicit conversion from void * to other pointer types but C++ does not (for type safety reasons).
Specifically, C allows a void* pointer to be assigned to any pointer type without a cast, while C++ does not; this idiom appears often in C code using malloc memory allocation, [9] or in the passing of context pointers to the POSIX pthreads API, and other frameworks involving callbacks. For example, the following is valid in C but not C++:
C supports the use of pointers, a type of reference that records the address or location of an object or function in memory. Pointers can be dereferenced to access data stored at the address pointed to, or to invoke a pointed-to function. Pointers can be manipulated using assignment or pointer arithmetic. The run-time representation of a ...
The C++ Standard Library provides several generic containers, functions to use and manipulate these containers, function objects, generic strings and streams (including interactive and file I/O), support for some language features, and functions for common tasks such as finding the square root of a number.