Tcl_Alloc(3)						      Tcl Library Procedures						      Tcl_Alloc(3)

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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.	If ptr is NULL, this is equivalent
       to calling Tcl_Alloc with just the size argument.

       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, but not all, attempting to allocate a zero-sized 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,  how-
       ever,  these macros are redefined to be special debugging versions 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

Tcl									7.5							      Tcl_Alloc(3)