REALLOC(3) BSD Library Functions Manual REALLOC(3)NAME
realloc — reallocation of memory function
realloc(void *ptr, size_t size);
The realloc() 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() 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() function, or if the space has been deallocated by a call to the
free or realloc() function, unpredictable and usually detrimental behav‐
ior 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() function returns either a null pointer or a pointer to the
possibly moved allocated space.
SEE ALSOalloca(3), calloc(3), free(3), malloc(3),
The realloc() function conforms to ANSI X3.159-1989 (“ANSI C89”).
BSD April 19, 1994 BSD