---
name: "UniCharIsAlpha"
section: "3"
platform: "macos"
package: "tcl"
version: "152"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/UniCharIsAlpha"
---

# UniCharIsAlpha(3)

routines for classification of Tcl\_UniChar characters

## NAME

Tcl\_UniCharIsAlnum, Tcl\_UniCharIsAlpha, Tcl\_UniCharIsControl, Tcl\_UniCharIsDigit, Tcl\_UniCharIsGraph, Tcl\_UniCharIsLower, Tcl\_UniCharIsPrint, Tcl\_UniCharIsPunct, Tcl\_UniCharIsSpace, Tcl\_UniCharIsUpper, Tcl\_UniCharIsWordChar - routines for classification of Tcl\_UniChar characters

## SYNOPSIS

```
#include <tcl.h>

int
Tcl_UniCharIsAlnum(ch)

int
Tcl_UniCharIsAlpha(ch)

int
Tcl_UniCharIsControl(ch)

int
Tcl_UniCharIsDigit(ch)

int
Tcl_UniCharIsGraph(ch)

int
Tcl_UniCharIsLower(ch)

int
Tcl_UniCharIsPrint(ch)

int
Tcl_UniCharIsPunct(ch)

int
Tcl_UniCharIsSpace(ch)

int
Tcl_UniCharIsUpper(ch)

int
Tcl_UniCharIsWordChar(ch)
```

## ARGUMENTS

The Tcl\_UniChar to be examined.

## DESCRIPTION

All of the routines described examine Tcl\_UniChars and return a boolean value. A non-zero return value means that the character does belong to the character class associated with the called routine. The rest of this document just describes the character classes associated with the various routines.

Note: A Tcl\_UniChar is a Unicode character represented as an unsigned, fixed-size quantity.

## CHARACTER CLASSES

**Tcl\_UniCharIsAlnum** tests if the character is an alphanumeric Unicode character.

**Tcl\_UniCharIsAlpha** tests if the character is an alphabetic Unicode character.

**Tcl\_UniCharIsControl** tests if the character is a Unicode control character.

**Tcl\_UniCharIsDigit** tests if the character is a numeric Unicode character.

**Tcl\_UniCharIsGraph** tests if the character is any Unicode print character except space.

**Tcl\_UniCharIsLower** tests if the character is a lowercase Unicode character.

**Tcl\_UniCharIsPrint** tests if the character is a Unicode print character.

**Tcl\_UniCharIsPunct** tests if the character is a Unicode punctuation character.

**Tcl\_UniCharIsSpace** tests if the character is a whitespace Unicode character.

**Tcl\_UniCharIsUpper** tests if the character is an uppercase Unicode character.

**Tcl\_UniCharIsWordChar** tests if the character is alphanumeric or a connector punctuation mark.

## KEYWORDS

unicode, classification