.TH ean13 1 2024-03-15 utils

.SH NAME
ean13 \- check or compute european article numbers

.SH SYNOPSIS
.B ean13
.RI [ arg\ ... ]

.SH DESCRIPTION
.B ean13
checks for each argument if it is a valid EAN13 number,
that is a European Article Number that has 13 digits;
or computes the checksum digit if the argument has only 12 digits. 

.SH EXIT STATUS
.TP
.B 0
If the number is valid or the checksum is computed.

.TP
.B 1
If the number is not valid.

.SH EXAMPLES
.HP
Compute the checksum number:

.BR ean13 \ 012345678901

.HP
Check if the number is a valid EAN13:

.BR ean13 \ 0123456789012