---
name: "form_variables"
section: "3x"
platform: "macos"
package: "ncurses"
version: "79"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/form_variables/3x"
---

# form\_variables(3x)

form system global variables

## NAME

**TYPE\_ALNUM**, **TYPE\_ALPHA**, **TYPE\_ENUM**, **TYPE\_INTEGER**, **TYPE\_IPV4**, **TYPE\_NUMERIC**, **TYPE\_REGEXP** - form system global variables

## SYNOPSIS

```
#include <form.h>
```

**FIELDTYPE \* TYPE\_ALNUM;** **FIELDTYPE \* TYPE\_ALPHA;** **FIELDTYPE \* TYPE\_ENUM;** **FIELDTYPE \* TYPE\_INTEGER;** **FIELDTYPE \* TYPE\_IPV4;** **FIELDTYPE \* TYPE\_NUMERIC;** **FIELDTYPE \* TYPE\_REGEXP;**

## DESCRIPTION

These are building blocks for the form library, defining fields that can be created using **set\_fieldtype**(3X). Each provides functions for field- and character-validation, according to the given datatype.

### TYPE\_ALNUM

This holds alphanumeric data.

### TYPE\_ALPHA

This holds alphabetic data.

### TYPE\_ENUM

This holds an enumerated type.

### TYPE\_INTEGER

This holds a decimal integer.

### TYPE\_IPV4

This holds an IPv4 internet address, e.g., "127.0.0.1".

### TYPE\_NUMERIC

This holds a decimal number, with optional sign and decimal point.

### TYPE\_REGEXP

This holds a regular expression.

## PORTABILITY

The **TYPE\_IPV4** variable is an extension not provided by older implementations of the form library.

## SEE ALSO

**form**(3X).