realloc(3) - NetBSD Manual Pages

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REALLOC(3)                NetBSD Programmer's Manual                REALLOC(3)


NAME

     realloc - reallocation of memory function


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <stdlib.h>

     void *
     realloc(void *ptr, size_t size);


DESCRIPTION

     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 be-
     havior 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.


RETURN VALUES

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


SEE ALSO

     alloca(3), calloc(3), free(3), malloc(3)


STANDARDS

     The realloc() function conforms to ANSI X3.159-1989 (``ANSI C'').

NetBSD 1.4                      April 19, 1994                               1