isnum(USP)

Name

isnum : Checks if the argument is a number

Synopsis

Usage   : isnum <num>

Version : Mon Jan 17 11:50:14 JST 2022

Edition : 1

Description

This command exits normally if <num> is a number, otherwise it exits

with an error (exit status 1).

Example

$ isnum 1234

$ echo $?

0

$ isnum abcd

$ echo $?

1

$ isnum -123 <-- Negatives cause an error

$ echo $?

1