---
name: "function::isdigit"
section: "3stap"
platform: "linux"
package: "systemtap-doc"
version: "5.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/function::isdigit"
---

# function::isdigit(3stap)

Checks for a digit

## NAME

function::isdigit - Checks for a digit

## SYNOPSIS

```
    isdigit:long(str:string)
```

## ARGUMENTS

*str*

string to check

## DESCRIPTION

Checks for a digit (0 through 9) as the first character of a string. Returns non-zero if true, and a zero if false.

## SEE ALSO0

[*tapset::string*(3stap)](/tapset::string/3stap.md)