array(3) The array library interface


#include <array.h>


An allocated array variable keeps track of

  • a (nonzero) pointer to a dynamically allocated region of memory;
  • the number of bytes allocated (always positive); and
  • the number of bytes initialized (between 0 and the number of bytes allocated).

There are two other possibilities for the state of an array variable: unallocated and failed. In both cases, there is no dynamically allocated region of memory.

A new array variable is normally created as a static variable:

  #include "array.h"

  static array x;

At this point it is unallocated. The array library provides various allocation and inspection functions.

A new array variable can also be created dynamically. It must be initialized to all-0, meaning unallocated, before it is given to any of the array functions. It must be returned to the unallocated (or failed) state, for example with array_reset, before it is destroyed. These rules prevent all memory leaks.

Expansion and inspection

  array x;

  t* p1 = array_allocate(&x,sizeof(t),pos);

  t* p2 = array_get(&x,sizeof(t),pos);

  t* p3 = array_start(&x);

  int64 len = array_length(&x,sizeof(t));

  int64 bytes = array_bytes(&x);

Truncation and deallocation

  array x;






  array x;
  array y;

  if (array_equal(&x,&y))
    /* arrays are equal... */


  array x;
  array y;




  array_cats0(&x,"fnord"); /* also append the \0 */

  array_cat0(&x); /* append \0 */

  array_cate(&x,"fnord",1,4); /* append "nor" */