File/Random version 0.07 ======================== NAME File::Random - Perl module for random selecting of a file SYNOPSIS use File::Random qw/random_file/; my $fname = random_file(); my $fname2 = random_file(-dir => $dir); my $random_gif = random_file(-dir => $dir, -check => qr/\.gif$/, -recursive => 1); my $no_exe = random_file(-dir => $dir, -check => sub {! -x}); my @jokes_of_the_day = content_of_random_file(-dir => '/usr/lib/jokes'); my $joke_of_the_day = content_of_random_file(-dir => '/usr/lib/jokes'); DESCRIPTION This module simplifies the routine job of selecting a random file. (As you can find at CGI scripts). It's done, because it's boring (and errorprone), always to write something like my @files = (<*.*>); my $randf = $files[rand @files]; or opendir DIR, " ... " or die " ... "; my @files = grep {-f ...} (readdir DIR); closedir DIR; my $randf = $files[rand @files]; It also becomes very boring and very dangerous to write randomly selection for subdirectory searching with special check-routines. FUNCTION random_file Returns a randomly selected file(name) from the specified directory If the directory is empty, undef will be returned. There 3 options: my $file = random_file( -dir => $dir, -check => qr/.../, # or sub { .... } -recursive => 1 # or 0 ); -dir Specifies the directory where file has to come from. Is the -dir option missing, a random file from the current directory will be used. That means '.' is the default for the -dir option. -check With the -check option you can either define a regex every filename has to follow, or a sub routine which gets the filename as argument. The filename includes the relative path (from the -dir directory or the current directory). Note, that -check doesn't accept anything else than a regexp or a subroutine. A string like '/.../' won't work. I still work on that. The default is no checking (undef). -recursive Enables, that subdirectories are scanned for files, too. Every file, independent from its position in the file tree, has the same chance to be choosen. Now the relative path from the given subdirectory or the current directory of the randomly choosen file is included to the file name. Every true value sets recursive behaviour on, every false value switches off. The default if false (undef). Note, that I programmed the recursive routine very defendly (using File::Find). So switching -recursive on, slowers the program a bit :-) FUNCTION content_of_random_file Returns the content of a randomly selected random file. In list context it returns an array of the lines of the selected file, in scalar context it returns a multiline string with whole the file. The lines aren't chomped. This function has the same parameter and a similar behaviour to the random_file method. Note, that -check still gets the filename and not the filecontent. EXPORT None by default. You can export the function random_file with "use File::Random qw/random_file/;", "use File::Random qw/content_of_random_file/" or with the more simple "use File::Random qw/:all/;". I didn't want to pollute namespaces as I could imagine, users write methods random_file to create a file with random content. If you think I'm paranoid, please tell me, then I'll take it into the export. TODO I think, I'll need to expand the options. Instead of only one directory, it should be possible to take a random file from some directories. The -check option doesn't except a string looking like a regexp. In future versions there should be the possibility of passing a string like '/..../' instead of the regexp qr/.../'; To create some aliases for the params is a good idea, too. I thought to make -d == -dir, -r == -recursive and -c == -check. (Only a lazy programmer is a good programmer). So I want to make it possible to write: my $fname = random_file( -dir => '...', -recursive => 1, -check => '/\.html/' ); or even: my $fname = random_file( -d => [$dir1, $dir2, $dir3, ...], -r => 1, -c => sub {-M < 7} ); A "-firstline" or "-lines =" [1 .. 10]> option for the "content_of_random_file" could be useful. Later something like "-randomline" option should be implemented, too. (Making the same as "random_line( random_file( ... ) )") "content_of_random_file" is very long, perhaps I'll implement a synonym "corf". Also speed could be improved, as I tried to write the code very readable, but wasted sometimes a little bit speed. (E.g. missing -check is translated to something like -check => sub{1}) As Functionality and Readability is more important than speed, I'll wait a little bit with speeding up :-) Using unknown params should bring a warning. At the moment they are ignored. The next thing, I'll implement is the "random_line" function. Please feel free to suggest me anything what could be useful. BUGS Oh, I hope none. I still have more test lines than function code. However, it's still BETA code. Well, but because I want some random data, it's a little bit hard to test. So a test could be wrong, allthough everything is O.K.. To avoid it, I let many tests run, so that the chances for misproofing should be < 0.0000000001% or so. Even it has the disadvantage that the tests need really long :-( I'm not definitly sure whether my test routines runs on OS, with path seperators different of '/', like in Win with '\\'. Perhaps anybody can try it and tell me the result. [But remember Win* is definitly the greater bug.] DEPENDENCIES This module requires these other modules and libraries: Test::More Test::Exception Test::Class Set::Scalar All these modules are needed only for the tests. You can work with the module even without them. These modules are only needed for my test routines, not by the File::Random itself. (However, it's a good idea to install the modules anyway). SEE ALSO the Tie::Pick manpage the Data::Random manpage COPYRIGHT AND LICENCE This module is free software. You can change and redistribute it under the same condition as Perl self. Copyright (C) 2002 Janek Schleicher,