Thanks a lot for reading this post.
I am trying to learn shell and Unix well. I am taking course at UNT school, unfortunately, the professor doesn't explain well. I am trying to take an advantage of this course and learn as much as I could. I learn by myself.. read the book which is fantastic book.. System programming with C and Unix, Hoover Book.. I am trying to answer the questions. However, I don't know if I am doing well or not. Does anyone have the book manual solution? or knows any web that I can have it?
To learn "shell and UNIX" well it ls IMHO not necessary to study systems programming. This is nothing against the value of systems programming, but you can learn the workings of UNIX (and especially the shell) without knowing system calls. My suggestion is to first learn the basics - which in this case means concepts and ideas behind UNIX - and only then deepen this knowledge by learning systems programming. This way you avoid being overwhelmed by too much information at once.
I suggest Andrew Tanenbaums "Modern Operating Systems". He explains a lot of the ideas and architectural decisions behind UNIX and you will get a good understanding of why things work the way they do.
A second book I'd suggest is W. Richard Stevens "TCP/IP Illustrated". UNIX and TCP/IP networking is inseparable and to understand UNIX is virtually impossible without a foundation of how networking works. The first volume deals with the protocols and will be sufficient for a starter but you will be delighted that Vol.3 contains a complete TCP/IP stack in heavily commented source code.