Sah::Schema::unix::username - Unix account name


This document describes version 0.012 of Sah::Schema::unix::username (from Perl distribution Sah-Schemas-Unix), released on 2020-06-13.


To check data against this schema (requires Data::Sah):

 use Data::Sah qw(gen_validator);
 my $validator = gen_validator("unix::username*");
 say $validator->($data) ? "valid" : "INVALID!";

 # Data::Sah can also create validator that returns nice error message string
 # and/or coerced value. Data::Sah can even create validator that targets other
 # language, like JavaScript. All from the same schema. See its documentation
 # for more details.

To validate function parameters against this schema (requires Params::Sah):

 use Params::Sah qw(gen_validator);

 sub myfunc {
     my @args = @_;
     state $validator = gen_validator("unix::username*");

To specify schema in Rinci function metadata and use the metadata with Perinci::CmdLine to create a CLI:

 # in lib/
 package MyApp;
 our %SPEC;
 $SPEC{myfunc} = {
     v => 1.1,
     summary => 'Routine to do blah ...',
     args => {
         arg1 => {
             summary => 'The blah blah argument',
             schema => ['unix::username*'],
 sub myfunc {
     my %args = @_;

 # in
 package main;
 use Perinci::CmdLine::Any;

 # in command-line
 % ./ --help
 myapp - Routine to do blah ...

 % ./ --version

 % ./ --arg1 ...

Sample data:

 ""  # INVALID

 "foo"  # valid

 "-andy"  # INVALID

 1234  # INVALID

 "andy2"  # valid

 "an dy"  # INVALID

 "an.dy"  # valid

 0  # INVALID (Too long)


The checking follows POSIX rules: does not begin with a hyphen and only contains [A-Za-z0-9._-].

The above rule allows integers like 1234, which can be confused with UID, so this schema disallows pure integers.

The maximum length is 32 following libc6's limit.


Please visit the project's homepage at


Source repository is at


Please report any bugs or feature requests on the bugtracker website

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.


perlancar <>


This software is copyright (c) 2020, 2019 by

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.