XtCalloc (3) - Linux Manuals

XtCalloc: memory management functions

NAME

XtMalloc, XtCalloc, XtRealloc, XtFree, XtNew, XtNewString - memory management functions

SYNTAX

#include <X11/Intrinsic.h>

char *XtMalloc(Cardinal size);

char *XtCalloc(Cardinal num, Cardinal size);

char *XtRealloc(char *ptr, Cardinal num);

void XtFree(char *ptr);

type *XtNew(type);

String XtNewString(String string);

Cardinal XtAsprintf(char **new_string, const char *format, ...);

ARGUMENTS

num

Specifies the number of bytes or array elements.

ptr

Specifies a pointer to the old storage or to the block of storage that is to be freed.

size

Specifies the size of an array element (in bytes) or the number of bytes desired.

string

Specifies a previously declared string.

type

Specifies a previously declared data type.

new_string

Specifies a pointer to write a newly allocated string to.

format

Specifies a formatting string as defined by sprintf(3c)

DESCRIPTION

The XtMalloc functions returns a pointer to a block of storage of at least the specified size bytes. If there is insufficient memory to allocate the new block, XtMalloc calls XtErrorMsg.

The XtCalloc function allocates space for the specified number of array elements of the specified size and initializes the space to zero. If there is insufficient memory to allocate the new block, XtCalloc calls XtErrorMsg.

The XtRealloc function changes the size of a block of storage (possibly moving it). Then, it copies the old contents (or as much as will fit) into the new block and frees the old block. If there is insufficient memory to allocate the new block, XtRealloc calls XtErrorMsg. If ptr is NULL, XtRealloc allocates the new storage without copying the old contents; that is, it simply calls XtMalloc.

The XtFree function returns storage and allows it to be reused. If ptr is NULL, XtFree returns immediately.

XtNew returns a pointer to the allocated storage. If there is insufficient memory to allocate the new block, XtNew calls XtErrorMsg. XtNew is a convenience macro that calls XtMalloc with the following arguments specified:

((type *) XtMalloc((unsigned) sizeof(type))

XtNewString returns a pointer to a new string which is a duplicate of string. If there is insufficient memory to allocate the new block, or the argument is NULL XtNewString returns NULL. The memory can be freed with XtFree.

The XtAsprintf function allocates space for a string large enough to hold the string specified by the sprintf(3c) format pattern when used with the remaining arguments, and fills it with the formatted results. The address of the allocated string is placed into the pointer passed as ret. The length of the string (not including the terminating null byte) is returned. If there is insufficient memory to allocate the new block, XtAsprintf calls XtErrorMsg.