Site for admins about operating systems and security
Any general purpose distribution for Raspberry Pi?
In theory any distribution supporting the ARM architecture could work, but for general purposes usage and specific for Raspberry Pi we have Raspbian.
Others are
RetroPie: to run arcade games.
Open Media Vault: as media server.
How can I detect all directories in a website?
You need to use pentest tools, for example this one provided by the Kali distribution:
Is there any other pager similar to more or less?
Yes, please look for most
Does Slackware support PAM?
PAM is not present in the standard Slackware build as is not inline with its creators philosophy.
If you want you can try to enable PAM support for a specific application you need.
There`s also the project Dlackware to add gnome3 + pam + systemd on top of Slackware SlackBuilds (see https://github.com/Dlackware ).
Is there any Linux shell like, but for Android?
Yes, look for termux.
Are there any tools like top, but for network traffic?
See nethogs and ntop for instance.
Any free bare metal recovery solution?
You can try Relax-and-Recover from http://relax-and-recover.org/.
Is there any tool to read from a file and then write to it in the same command line through a pipe?
Yes, sponge from the package moreutils.
Is there any Debian distro like without Systemd in 2019?
Sure: Devuan, Trisquel, Antix Linux and Mx Linux.