| ActiveTcl User Guide |

## Tcl/Tk Documentation > TclLib > UniCharIsAlpha

### Tcl/Tk Applications | Tcl Commands | Tk Commands | Tcl Library | Tk Library

### 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

int ch (in)
  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
Copyright © 1995-1997 Roger E. Critchlow Jr. Copyright © 1997 Sun Microsystems, Inc.