---
name: "usetat"
section: "3alleg4"
platform: "linux"
package: "allegro4-doc"
version: "2:4.4.3.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/usetat/3alleg4"
---

# usetat(3alleg4)

Replaces a character in a string. Allegro game programming library.

## NAME

usetat - Replaces a character in a string. Allegro game programming library.

## SYNOPSIS

**#include \<allegro.h\>**

**int usetat(char \*s, int index, int c);**

## DESCRIPTION

Replaces the character at the specified index in the string with value \`c', handling any adjustments for variable width data (ie. if \`c' encodes to a different width than the previous value at that location). If \`index' is negative, it counts backward from the end of the string. Example:

```
   usetat(text_string, 2, letter_a);
```

## RETURN VALUE

Returns the number of bytes by which the trailing part of the string was moved. This is of interest only with text encoding formats where characters have a variable length, like UTF-8.

## SEE ALSO

**uoffset**(3alleg4), **ugetat**(3alleg4), **uinsert**(3alleg4), **uremove**(3alleg4)