From 4506c1e56ec89ad42c1a37f4b9b41204e4d991d1 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Sat, 27 Dec 2025 22:37:47 +0100 Subject: First commit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- README | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 README (limited to 'README') diff --git a/README b/README new file mode 100644 index 0000000..08f88d5 --- /dev/null +++ b/README @@ -0,0 +1,40 @@ +NAME + luhncheck - Check number with Luhn's algorithm + +SYNOPSIS + luhncheck number ... + +DESCRIPTION + The luhncheck utility checks that a number, containing a + check digit, is valid according to Luhn's algorithm. + +OPTIONS + The luhncheck utility conforms to the Base Definitions volume + of POSIX.1-2017, Section 12.2, Utility Syntax Guidelines. + + No options are supported. + +OPERANDS + The following operand is supported: + + number + Number to check. + +STDOUT + The luhncheck utility will print one line per number, in the + order they are provided in the command line, to the standard + output. Each line will be use the format + + "%s is %s\n", number, <"OK" if valid, "invalid" otherwise>. + +EXIT STATUS + The following exit values are returned: + + 0 All numbers are valid. + + 1 At least one number is invalid. + + 2 An error occured. + +SEE ALSO + gluhncheck(1) -- cgit v1.2.3-70-g09d2