---
name: "XtMalloc"
section: "3x"
platform: "linux"
package: "libxt-dev"
version: "4.3.0.dfsg.1-14sarge7"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/XtMalloc/3x"
---

# XtMalloc(3x)

memory management functions

## NAME

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

## SYNTAX

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*);

## 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.

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

```
(strcpy(XtMalloc((unsigned) strlen(str) + 1), str))

```

## SEE ALSO

*X Toolkit Intrinsics - C Language Interface*\
 *Xlib - C Language X Interface*