If I want to start programming in Linux, is C language is enough?

exactly what did you want to program in linux?

start by learning the bourne shell and how to script it
then learn sed and awk
then learn perl or python

then, if you feel the need, learn c

freebsd is better anyway

a far less faggy user community

>>2
i'm instresting in system programming

>>1
More information needed . . . I'm a C programmer, this doesn't mean I can do shit with linux quickly or easily. You need to work with networking, graphics, system administration, or what?

>>4
yeah then learn c. also learn what style your code should be in if you wish to be a contributor.

on freebsd its on the style(9) man page.

also learn whatever linux uses for its code repository like cvs.

frankly, mac os/darwin so out-linuxes linux that its not even funny.

again, start by learning how to use a shell

>>6
is it worth to go this way in 2015? system programming way.

freebsd can run build and run linux stuff natively with the linuxulator. freebsd > linux but im a bsd biggot. started with BSDI back in the mid 90s

>>8
i don't know what you mean by system programming.

that's like saying you want to play music without specifying an instrument or style.

start by installing linux on something. if you cant get an install up and running there's no point in going further...

>>10
I bought a book called Linux System Programming: Talking Directly to the Kernel and C Library. I'm the beginner so I can't speak precisely. I'm interested in to start my adventure with Linux. I'm already using Linux Mint, but I want to go deeper and start do something great.

IMO you should start learning C## on Windows and when you understand it transit to linux would be quite easy