---
name: "Xutf8LookupString"
section: "3x"
platform: "linux"
package: "libx11-dev"
version: "4.3.0.dfsg.1-14sarge7"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/XmbLookupString/3x"
---

# Xutf8LookupString(3x)

obtain composed input from an input method

Part of [XmbLookupString(3x)](/XmbLookupString/3x.md).

## NAME

XmbLookupString, XwcLookupString, Xutf8LookupString - obtain composed input from an input method

## SYNTAX

int XmbLookupString(XIC *ic*, XKeyPressedEvent \**event*, char \**buffer\_return*, int *bytes\_buffer*, KeySym \**keysym\_return*, Status \**status\_return*);

int XwcLookupString(XIC *ic*, XKeyPressedEvent \**event*, wchar\_t \**buffer\_return*, int *wchars\_buffer*, KeySym \**keysym\_return*, Status \**status\_return*);

int Xutf8LookupString(XIC *ic*, XKeyPressedEvent \**event*, char \**buffer\_return*, int *bytes\_buffer*, KeySym \**keysym\_return*, Status \**status\_return*);

## ARGUMENTS

- *buffer\_return*

  Returns a multibyte string or wide character string (if any) from the input method.

- *bytes\_buffer*

  - *wchars\_buffer*

  Specifies space available in the return buffer.

- *event*

  Specifies the key event to be used.

- *ic*

  Specifies the input context.

- *keysym\_return*

  Returns the KeySym computed from the event if this argument is not NULL.

- *status\_return*

  Returns a value indicating what kind of data is returned.

## DESCRIPTION

The *XmbLookupString*, *XwcLookupString* and *Xutf8LookupString* functions return the string from the input method specified in the buffer\_return argument. If no string is returned, the buffer\_return argument is unchanged.

The KeySym into which the KeyCode from the event was mapped is returned in the keysym\_return argument if it is non-NULL and the status\_return argument indicates that a KeySym was returned. If both a string and a KeySym are returned, the KeySym value does not necessarily correspond to the string returned.

*XmbLookupString* and *Xutf8LookupString* return the length of the string in bytes, and *XwcLookupString* returns the length of the string in characters. Both *XmbLookupString* and *XwcLookupString* return text in the encoding of the locale bound to the input method of the specified input context, and *Xutf8LookupString* returns text in UTF-8 encoding.

Each string returned by *XmbLookupString* and *XwcLookupString* begins in the initial state of the encoding of the locale (if the encoding of the locale is state-dependent).

Note

To ensure proper input processing, it is essential that the client pass only  *KeyPress* events to *XmbLookupString*, *XwcLookupString* and *Xutf8LookupString*. Their behavior when a client passes a  *KeyRelease* event is undefined.\

Clients should check the status\_return argument before using the other returned values. These three functions each return a value to status\_return  that indicates what has been returned in the other arguments. The possible values returned are:

| | |
| --- | --- |
|  | The input string to be returned is too large for the supplied buffer\_return. The required size (for in bytes; for in characters) is returned as the value of the function, and the contents of buffer\_return and keysym\_return are not modified. The client should recall the function with the same event and a buffer of adequate size to obtain the string. |
|  | No consistent input has been composed so far. The contents of buffer\_return and keysym\_return are not modified, and the function returns zero. |
|  | Some input characters have been composed. They are placed in the buffer\_return argument, using the encoding described above, and the string length is returned as the value of the function. The content of the keysym\_return argument is not modified. |
|  | A KeySym has been returned instead of a string and is returned in keysym\_return. The content of the buffer\_return argument is not modified, and the function returns zero. |
|  | Both a KeySym and a string are returned; and occur simultaneously. |

It does not make any difference if the input context passed as an argument to *XmbLookupString*, *XwcLookupString* and *Xutf8LookupString* is the one currently in possession of the focus or not. Input may have been composed within an input context before it lost the focus, and that input may be returned on subsequent calls to *XmbLookupString*, *XwcLookupString* or *Xutf8LookupString* even though it does not have any more keyboard focus.

The function *Xutf8LookupString* is an XFree86 extension introduced in XFree86 4.0.2. Its presence is indicated by the macro *X\_HAVE\_UTF8\_STRING*.

## SEE ALSO

XLookupKeysym(3X11)\
 *Xlib - C Language X Interface*