i have to read a verilog file in c ..how will be the code in general?

Do you just need to read it line by line, or do you need to actually tokenize and parse the verilog language?

i need to read it line by line

Then unless you already have a strong foundation in compiler development, I'd suggest starting with something like the dragon book. You can also search google for tutorials on writing a compiler, and focus on the tokenizing/parsing parts.

But since you're doing that, I'd wager you'll also need to interpret the language at some point, and the end result will be a fairly complete compiler. Such a project is far too large for anyone to simply tell you how the code will be, by the way.

how will be the c programing code which will have all the basic gates information(or,and,nand,nor,exor,exnor,not....)