curs\_clear(3X) Library calls curs\_clear(3X)

# [NAME](#NAME)

**erase**, **werase**, **clear**, **wclear**, **clrtobot**, **wclrtobot**, **clrtoeol**, **wclrtoeol** - clear all or part of a *curses* window

# [SYNOPSIS](#SYNOPSIS)

```
#include <curses.h>
```

```
int erase(void);
int werase(WINDOW *win);
```

```
int clear(void);
int wclear(WINDOW *win);
```

```
int clrtobot(void);
int wclrtobot(WINDOW *win);
```

```
int clrtoeol(void);
int wclrtoeol(WINDOW *win);
```

# [DESCRIPTION](#DESCRIPTION)

## [erase, werase](#erase,_werase)

The **erase** and **werase** routines copy blanks to every position in the window, clearing the screen.

Blanks created by erasure have the current background rendition (as set by [**wbkgdset**(3X)](/man/os/ncurses/wbkgdset.3X)) merged into them.

## [clear, wclear](#clear,_wclear)

The **clear** and **wclear** routines are like **erase** and **werase**, but they also call [**clearok**(3X)](/man/os/ncurses/clearok.3X), so that the screen is cleared completely on the next call to **wrefresh** for that window and repainted from scratch.

## [clrtobot, wclrtobot](#clrtobot,_wclrtobot)

The **clrtobot** and **wclrtobot** routines erase from the cursor to the end of screen. That is, they erase all lines below the cursor in the window. Also, the current line to the right of the cursor, inclusive, is erased.

## [clrtoeol, wclrtoeol](#clrtoeol,_wclrtoeol)

The **clrtoeol** and **wclrtoeol** routines erase the current line to the right of the cursor, inclusive, to the end of the current line.

# [RETURN VALUE](#RETURN_VALUE)

All routines return the integer **OK** on success and **ERR** on failure.

In this implementation,

- functions using a window pointer parameter return **ERR** if it is null
- **wclrtoeol** returns an error if the cursor position is about to wrap.

# [NOTES](#NOTES)

**erase**, **werase**, **clear**, **wclear**, **clrtobot**, and **clrtoeol** may be implemented as macros.

# [PORTABILITY](#PORTABILITY)

X/Open Curses Issue 4 describes these functions. It specifies no error conditions for them.

SVr4 documentation says that these functions return *OK* “or a non-negative integer if *immedok()* is set”, referring to the return value from *wrefresh*, which in SVr4 returns a count of characters written to the window if its *immedok* property is set; in *ncurses*, it does not.

Some historic curses implementations had, as an undocumented feature, the ability to do the equivalent of **clearok(..., 1)** by saying **touchwin(stdscr)** or **clear(stdscr)**. This will not work under *ncurses*.

This implementation, and others such as Solaris, sets the current position to 0,0 after erasing via **werase** and **wclear**. That fact is not documented in other implementations, and may not be true of implementations which were not derived from SVr4 source.

Not obvious from the description, most implementations clear the screen after **wclear** even for a subwindow or derived window. If you do not want to clear the screen during the next **wrefresh**, use **werase** instead.

# [SEE ALSO](#SEE_ALSO)

[**curses**(3X)](/man/os/ncurses/curses.3X), [**curs\_outopts**(3X)](/man/os/ncurses/curs_outopts.3X), [**curs\_refresh**(3X)](/man/os/ncurses/curs_refresh.3X), [**curs\_variables**(3X)](/man/os/ncurses/curs_variables.3X)

2025-01-18 ncurses 6.6

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Document: wclrtoeol(3x) from ncurses 6.6.20261010-r0 (Chainguard OS)
Source: https://github.com/ThomasDickey/ncurses-snapshots