NAME

       Tcl_Alloc,  Tcl_Free,  Tcl_Realloc,  Tcl_AttemptAlloc,  Tcl_AttemptRealloc,  ckalloc,  ckfree, ckrealloc,
       attemptckalloc, attemptckrealloc - allocate or free heap memory

SYNOPSIS

       #include <tcl.h>

       char *
       Tcl_Alloc(size)

       void
       Tcl_Free(ptr)

       char *
       Tcl_Realloc(ptr, size)

       char *
       Tcl_AttemptAlloc(size)

       char *
       Tcl_AttemptRealloc(ptr, size)

       char *
       ckalloc(size)

       void
       ckfree(ptr)

       char *
       ckrealloc(ptr, size)

       char *
       attemptckalloc(size)

       char *
       attemptckrealloc(ptr, size)

ARGUMENTS

       unsigned int   size(in)  Size in bytes of the memory block to allocate.

       char   *ptr    (in)      Pointer to memory block to free or realloc.
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DESCRIPTION

       These procedures provide a platform and compiler independent interface for memory  allocation.   Programs
       that  need to transfer ownership of memory blocks between Tcl and other modules should use these routines
       rather than the native malloc() and free() routines provided by the C run-time library.

       Tcl_Alloc returns a pointer to a block of at least size bytes suitably aligned for any use.

       Tcl_Free makes the space referred to by ptr available for further allocation.

       Tcl_Realloc changes the size of the block pointed to by ptr to size bytes and returns a  pointer  to  the
       new  block.   The  contents  will  be  unchanged up to the lesser of the new and old sizes.  The returned
       location may be different from ptr.

       Tcl_AttemptAlloc and Tcl_AttemptRealloc are identical in function to Tcl_Alloc  and  Tcl_Realloc,  except
       that  Tcl_AttemptAlloc  and  Tcl_AttemptRealloc will not cause the Tcl interpreter to panic if the memory
       allocation fails.  If the allocation fails,  these  functions  will  return  NULL.   Note  that  on  some
       platforms, attempting to allocate a block of memory will also cause these functions to return NULL.

       The  procedures  ckalloc,  ckfree,  ckrealloc,  attemptckalloc,  and  attemptckrealloc are implemented as
       macros.  Normally, they are synonyms for the corresponding procedures documented on this page.  When  Tcl
       and  all modules calling Tcl are compiled with TCL_MEM_DEBUG defined, however, these macros are redefined
       to be special debugging versions of of these procedures.  To support  Tcl's  memory  debugging  within  a
       module, use the macros rather than direct calls to Tcl_Alloc, etc.

KEYWORDS

       alloc, allocation, free, malloc, memory, realloc, TCL_MEM_DEBUG