'\" '\" Copyright (c) 1995-1996 Sun Microsystems, Inc. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" RCS: @(#) Alloc.3,v 1.5 2003/01/21 19:39:58 hunt Exp '\" .so man.macros .TH Tcl_Alloc 3 7.5 Tcl "Tcl Library Procedures" .BS .SH NAME Tcl_Alloc, Tcl_Free, Tcl_Realloc, Tcl_AttemptAlloc, Tcl_AttemptRealloc, ckalloc, ckfree, ckrealloc, attemptckalloc, attemptckrealloc \- allocate or free heap memory .SH SYNOPSIS .nf \fB#include <tcl.h>\fR .sp char * \fBTcl_Alloc\fR(\fIsize\fR) .sp void \fBTcl_Free\fR(\fIptr\fR) .sp char * \fBTcl_Realloc\fR(\fIptr, size\fR) .sp char * \fBTcl_AttemptAlloc\fR(\fIsize\fR) .sp char * \fBTcl_AttemptRealloc\fR(\fIptr, size\fR) .sp char * \fBckalloc\fR(\fIsize\fR) .sp void \fBckfree\fR(\fIptr\fR) .sp char * \fBckrealloc\fR(\fIptr, size\fR) .sp char * \fBattemptckalloc\fR(\fIsize\fR) .sp char * \fBattemptckrealloc\fR(\fIptr, size\fR) .SH ARGUMENTS .AS char *size .AP int size in Size in bytes of the memory block to allocate. .AP char *ptr in Pointer to memory block to free or realloc. .BE .SH DESCRIPTION .PP 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 \fBmalloc()\fR and \fBfree()\fR routines provided by the C run-time library. .PP \fBTcl_Alloc\fR returns a pointer to a block of at least \fIsize\fR bytes suitably aligned for any use. .PP \fBTcl_Free\fR makes the space referred to by \fIptr\fR available for further allocation. .PP \fBTcl_Realloc\fR changes the size of the block pointed to by \fIptr\fR to \fIsize\fR 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 \fIptr\fR. .PP \fBTcl_AttemptAlloc\fR and \fBTcl_AttemptRealloc\fR are identical in function to \fBTcl_Alloc\fR and \fBTcl_Realloc\fR, except that \fBTcl_AttemptAlloc\fR and \fBTcl_AttemptRealloc\fR will not cause the Tcl interpreter to \fBpanic\fR 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. .PP The procedures \fBckalloc\fR, \fBckfree\fR, \fBckrealloc\fR, \fBattemptckalloc\fR, and \fBattemptckrealloc\fR 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 \fBTCL_MEM_DEBUG\fR 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 \fBTcl_Alloc\fR, etc. .SH KEYWORDS alloc, allocation, free, malloc, memory, realloc, TCL_MEM_DEBUG