Re^5: standard library to return system paths

You can usually assume that your libraries are in some fixed place relative to the script path which you can find as $0.

Example:

# untested!
use File::Spec;
BEGIN {
    my $script = File::Spec->rel2abs($0);
    my ($drive, $dir) = File::Spec->splitpath($script);
    my $base = File::Spec->catpath($drive, $dir);
    if ($^O eq 'MSWin32') {
        push @INC, "$base\\lib";
    }
    else {
        push @INC, "$base/../lib";
    }
}
[download]

You just have to ensure that your Perl applications are installed using the fixed directory structure matching your code expectations.

Update: Also, on Windows you may like to store the path to your application on the registry when it is installed.

Comment on Re^5: standard library to return system paths Select or Download Code

Replies are listed 'Best First'.
Re^6: standard library to return system paths by igoryonya (Pilgrim) on Jun 07, 2016 at 09:06 UTC
Yes, you are correct, but... this type of thing I wanted to get away from, because it's a pain to add the same code to every program, that you do, so, exactly, I've put code similar to that in a library, that was placed to /etc/ folder and started just calling: require /etc/somelib.pl, like that. This approach has several problems: 1) it wouldn't work on most public webservers, because, I don't have a writeable access to /etc folder on a shared computer. 2) Windows has a different path for such folder, i.e.: c:\users\appdata\, or c:\program files\all users\application data, or it could even be on a different drive. So, I am facing not only a crossplatformness problem, but even on the same OS family, it could be located in different place, depending on the computer. After some further thought, that none of the answers gave me a desirable solution, I've came up with a solution, listed in my message update, that I find reasonable for the task: creating a crossplatform installer for sort of script 'boot loader' library. A simple library, that will be installed to a standard perl path, that will determine everything else in the currently running system. Later, I will fix it to detect the path, that the installer can write to, so the installer doesn't have to have super user privileges, I hope.	[reply]

Replies are listed 'Best First'.

Re^6: standard library to return system paths
by igoryonya (Pilgrim) on Jun 07, 2016 at 09:06 UTC

This approach has several problems:
1) it wouldn't work on most public webservers, because, I don't have a writeable access to /etc folder on a shared computer.
2) Windows has a different path for such folder, i.e.: c:\users\appdata\, or c:\program files\all users\application data, or it could even be on a different drive.

So, I am facing not only a crossplatformness problem, but even on the same OS family, it could be located in different place, depending on the computer.

After some further thought, that none of the answers gave me a desirable solution, I've came up with a solution, listed in my message update, that I find reasonable for the task: creating a crossplatform installer for sort of script 'boot loader' library.
A simple library, that will be installed to a standard perl path, that will determine everything else in the currently running system.

Later, I will fix it to detect the path, that the installer can write to, so the installer doesn't have to have super user privileges, I hope.

[reply]