Module drone_core::ffi::libc[][src]

Subset of C standard library.

This module implements some functions from libc. Thus it eases linking Drone applications with C libraries.

Dynamic memory functions (e.g. malloc, free) are implemented in terms of Drone Heap.

Functions

calloc

Allocates memory for an array of nmemb elements of size bytes each and returns a pointer to the allocated memory. The memory is set to zero. If nmemb or size is 0, then it returns either NULL, or a unique pointer value that can later be successfully passed to free.

free

Frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc, calloc, or realloc. Otherwise, or if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed.

malloc

Allocates size bytes and returns a pointer to the allocated memory. The memory is not initialized. If size is 0, then it returns either NULL, or a unique pointer value that can later be successfully passed to free.

realloc

Changes the size of the memory block pointed to by ptr to size bytes. The contents will be unchanged in the range from the start of the region up to the minimum of the old and new sizes. If the new size is larger than the old size, the added memory will not be initialized. If ptr is NULL, then the call is equivalent to malloc(size), for all values of size; if size is equal to zero, and ptr is not NULL, then the call is equivalent to free(ptr). Unless ptr is NULL, it must have been returned by an earlier call to malloc, calloc, or realloc. If the area pointed to was moved, a free(ptr) is done.

strchr

Returns a pointer to the first occurrence of the character c in the string s.

strcmp

Compares the two strings s1 and s2. It returns an integer less than, equal to, or greater than zero if s1 is found, respectively, to be less than, to match, or be greater than s2.

strlen

Calculates the length of the string s, excluding the terminating null byte ('\0').

Type Definitions

size_t

A type able to represent the size of any object in bytes.