realloc(3)                                                   realloc(3)

  realloc()

  NAME

    realloc() - reallocate memory

  SYNOPSIS

    #include 

    void * realloc (void *ptr, size_t size)

  DESCRIPTION

    The realloc(3) function changes the size of the object pointed to by ptr
    to the size specified by size. The contents of the object are unchanged up
    to the lesser of the new and old sizes. If the new size is larger, the
    value of the newly allocated portion of the object is indeterminate. If
    ptr is a null pointer, the realloc(3) function behaves like the malloc(3)
    function for the specified size. Otherwise, if ptr does not match a
    pointer earlier returned by the calloc(3), malloc(3), or realloc(3)
    function, or if the space has been deallocated by a call to the free(3) or
    realloc(3) function, unpredictable and usually detrimental behavior will
    occur. If the space cannot be allocated, the object pointed to by ptr is
    unchanged. If size is zero and ptr is not a null pointer, the object it
    points to is freed.

    The realloc(3) function returns either a null pointer or a pointer to the
    possibly moved allocated space.

  SEE ALSO

    calloc(3)

    free(3)

    malloc(3)

  USAGE NOTES

    The realloc function is thread safe.

    The realloc function is not async-signal safe.