---
name: "isnum"
section: "1"
platform: "linux"
package: "wcstools"
version: "3.9.7-1.1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/isnum"
---

# isnum(1)

Return code telling whether the input string is numerical

## Name

isnum - Return code telling whether the input string is numerical

## Synopsis

isnum string\

## Description

*isnum* is a utility for identifying and classifying an input string. \<B\>isnum\</B\> returns an integer code depending on how it identifies the  input number: 0: string is not any sort of number 1: String is an integer 2: String is a floating point number 3: String is a hh:mm:ss.ss time 4: String is a yyyy-mm-dd date

## Author

Jessica Mink, SAO (jmink@cfa.harvard.edu)