Advanced Bash Scripting Guide 

Complete ebook tutorial and reference on shell scripting with Bash in Linux/UNIX/BSD. This is the equivalent of a 672-page printed book.
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L-Nix 

L-nix is an interactive UNIX tutorial program that teaches beginner to advanced concepts of the UNIX operating system. L-nix includes a simple UNIX shell simulator allowing users to try out commands as they are learned.
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