NAME

Sah::Schema::filename - Filesystem file name

VERSION

This document describes version 0.030 of Sah::Schema::filename (from Perl distribution Sah-Schemas-Path), released on 2024-01-08.

SAH SCHEMA DEFINITION

 [
   "str",
   {
     "min_len"      => 1,
     "prefilters"   => [
                         "Path::expand_tilde_when_on_unix",
                         "Path::strip_slashes_when_on_unix",
                       ],
     "summary"      => "Filesystem file name",
     "x.completion" => ["filename"],
   },
 ]

Base type: str

Used prefilters: Path::expand_tilde_when_on_unix, Path::strip_slashes_when_on_unix

Used completion: filename

SYNOPSIS

Sample data and validation results against this schema

 ""  # INVALID

 "foo"  # valid

 "foo/bar"  # valid

Using with Data::Sah

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

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

The above validator returns a boolean result (true if data is valid, false if otherwise). To return an error message string instead (empty string if data is valid, a non-empty error message otherwise):

 my $validator = gen_validator("filename", {return_type=>'str_errmsg'});
 my $errmsg = $validator->($data);
 
 # a sample valid data
 $data = "foo";
 my $errmsg = $validator->($data); # => ""
 
 # a sample invalid data
 $data = "";
 my $errmsg = $validator->($data); # => "Length must be at least 1"

Often a schema has coercion rule or default value rules, so after validation the validated value will be different from the original. To return the validated (set-as-default, coerced, prefiltered) value:

 my $validator = gen_validator("filename", {return_type=>'str_errmsg+val'});
 my $res = $validator->($data); # [$errmsg, $validated_val]
 
 # a sample valid data
 $data = "foo";
 my $res = $validator->($data); # => ["","foo"]
 
 # a sample invalid data
 $data = "";
 my $res = $validator->($data); # => ["Length must be at least 1",""]

Data::Sah can also create validator that returns a hash of detailed error message. Data::Sah can even create validator that targets other language, like JavaScript, from the same schema. Other things Data::Sah can do: show source code for validator, generate a validator code with debug comments and/or log statements, generate human text from schema. See its documentation for more details.

Using with Params::Sah

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

 use Params::Sah qw(gen_validator);

 sub myfunc {
     my @args = @_;
     state $validator = gen_validator("filename*");
     $validator->(\@args);
     ...
 }

Using with Perinci::CmdLine::Lite

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

 # in lib/MyApp.pm
 package
   MyApp;
 our %SPEC;
 $SPEC{myfunc} = {
     v => 1.1,
     summary => 'Routine to do blah ...',
     args => {
         arg1 => {
             summary => 'The blah blah argument',
             schema => ['filename*'],
         },
         ...
     },
 };
 sub myfunc {
     my %args = @_;
     ...
 }
 1;

 # in myapp.pl
 package
   main;
 use Perinci::CmdLine::Any;
 Perinci::CmdLine::Any->new(url=>'/MyApp/myfunc')->run;

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

 % ./myapp.pl --version

 % ./myapp.pl --arg1 ...

Using on the CLI with validate-with-sah

To validate some data on the CLI, you can use validate-with-sah utility. Specify the schema as the first argument (encoded in Perl syntax) and the data to validate as the second argument (encoded in Perl syntax):

 % validate-with-sah '"filename*"' '"data..."'

validate-with-sah has several options for, e.g. validating multiple data, showing the generated validator code (Perl/JavaScript/etc), or loading schema/data from file. See its manpage for more details.

Using with Type::Tiny

To create a type constraint and type library from a schema (requires Type::Tiny as well as Type::FromSah):

 package My::Types {
     use Type::Library -base;
     use Type::FromSah qw( sah2type );

     __PACKAGE__->add_type(
         sah2type('filename*', name=>'Filename')
     );
 }

 use My::Types qw(Filename);
 Filename->assert_valid($data);

DESCRIPTION

This schema is basically string with some checks and prefilters. Why use this schema instead of plain ol' str? Mainly to give you the ability to change tilde to user's home directory, e.g. ~/foo.txt into /home/someuser/foo.txt. Normally this expansion is done by a Unix shell, but sometimes your program receives an unexpanded path, e.g. when you get it from some config file.

See also more OS-specific schemas like filename::unix, which adds some more checks (e.g. filename cannot contain forward slash and each component cannot be longer than 255 characters) and preprocessing (e.g. stripping extraneous slashes like foo//bar into foo/bar.

What's the difference between this schema and dirname? The default completion rule. dirname's completion only includes directories and not files.

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Sah-Schemas-Path.

SOURCE

Source repository is at https://github.com/perlancar/perl-Sah-Schemas-Path.

AUTHOR

perlancar <perlancar@cpan.org>

CONTRIBUTING

To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

 % prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE

This software is copyright (c) 2024, 2023, 2020, 2019, 2018, 2016 by perlancar <perlancar@cpan.org>.

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

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Sah-Schemas-Path

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.