Blundering on the CLI
Much to my own amusement, I’m still crashing around Linux like the proverbial bull in a china shop.
One of the odd things about working in an OS that you hardly ever use is there’s no “where is everything and how do I use it” button. Google brings up fifty ways to do the same thing, yet the syntax doesn’t quite work. I’m pretty sure most of the learned *Nix folks would be shaking their heads at the blundering of a Windows Admin in their home turf.
Thank goodness for the “revert to snapshot” button on in VMware workstation for when I download every piece of software for no real reason and stuff up a perfectly working environment.
Let me give you an example.
One of the objectives in the GSE is a simple netcat relay followed by lots of weird and twisted relays, then shove shell back to you with the lovely # prompt.
Normally this is easy, jump on to the final box type in nc –l –p 80 –e /bin/sh. Not on Fedora, which doen’t like the -l and –p being run together. So nc –l 80 –e /bin/sh then?
No – Fedora’s default installed out of the box netcat stops the evil shenanigans of the –e excution command. Oops, so you have to go and get then install another version of netcat, such as the original written by the Hobbit (make netcat, as along as long as there’s a complier on the box) which is on all Ed Skoudis’ SANS course materials or pulled download socat or one its friends.
Then using –e to shove a shell works tricks works fine.
Okay, so different OS have different versions of applications, but surely we could keep command syntax similar? Apparently not.
I decided to reach out for a bit of help and guidance, in the form of what books to read. The two I settled on were both recommendations by people in the know:
A Practical Guide to Fedora and Red Hat Enterprise Linux – Fifth Edition by Mark G. Sobell.
It’s all about Fedora 12, which is the subject of the current GSE Linux tests. Very solid and clear layout, comprehensively covering the features of Fedora and its syntax proving excellent examples
Unix and Linux System Administration Handbook – Forth Edition by Evi Nemeth, Garth Snyder, Trent Hein and Ben Whaley.
This one was recommended by Hal_Pomeranz, who wrote the SANS Linux 506 track, after I hassled him on twitter. This one goes covers many flavours of Linux and Unix, but it’s a marvelous journey through a SysAdmin approach to using *nix, making it a surprisingly easy read.
I don’t expect either book will make me a super admin over the next few weeks, but they go a great way to make me feel somewhat more at home and relaxed in Linux, rather than feeling like I just broken in to someone’s place and set fire to it.
