reading text file line by line and assigning each line to a variable in C language

This is a FAQ of most every newbie that have not yet understood what is the compiler job.

The answer cannot be given because there are a lot of things the question doesn't clarify.

1) Is the file content obeying to a particular format or syntax (i.e: is the content somehow "predictable") or can the file contain virtually anything?
From the question it seems correct to assume the file contains "text" diveded into "lines" somehow recognizable.
2) Is the number of line somehow fixed? May you stop reading after a given number of them or not?

The point, here, is understand that the concept of "variable" (local or global: a value identified by a name) is static: something you declare BEFORE the program runs. You cannot store lines in a variable amount of variables.

The problem, requires the use of dynamic structures, that can be expanded as the program runs (you don't know how much a line is long and how many lines are there), and that requires the use of dynamic memory and that requires the use of pointers (or, in C++, the use of classes that manages dynamic memory).

That said, the problem is solvable in a completely different manner in C and in C++ (so you have to choose what you want: C/C++ is a language that doesn't exist: C is C, C++ is C++. Just like you and your brother share the same surname, but you're not the same person, and not always interchangeable!)

Whatever the solution will be, you will not end-up with each line loaded in A (in the sense of his own named ...) variable, but with the entire file loaded into a data structure requiring some functions (or methods, or indexing or iteration ...) to access the content of the lines, since they will not be accessible by just naming them: they are created during execution, so that don't have "names", since names are declared at design time and -at compile time- no "file" is known yet.

It is now clear that you have to know a number of notions (mainly: the concept of vector, string and iteration or indexing plus the concept of stream, and -in C- the concept of array, dynamic allocation and deallocation and pointer) that is not clear if you already have it or not (I suppose you don't, otherwise your question wold have have a slightly different formulation and wording).

What I found strage is that many newbies stuck against this problem, that -in theory- should even not exist, since it comes to a misleading requirement and conceptualization: what do you have to do with those lines, after you read them?

First look yourself for the answer over Google. If you find any problem be specific to that.
General solution : look for new lien character as a string seprator in a file and fill it in variable.

Set your soul free :d

If you want C++, the solution is simple, since you can use the container classes from the Standard Template Library (STL). Declare your variable like this:

std::vector<std::string> > lines;

and it will store a variable number of lines of unspecified length. The classes will take care of allocating memory for you.

If you want C only, you need to set up and maintain a data structure of unknown dimensions yourself. As you stated you're just a beginner, I'd rather spare you the details unless the C++ solution is really not an option.

With regard to reading lines from a file, there are functions for both C and C++ to read entire lines of text from a file. Just let us know what language you use (and whether you actually need help with the reading functions)

P.S.:
After reading over solution 2 (and commenting on it), I felt that I should add this:

Your task really has three aspects that you will need to solve:
1. Store an unknown number of values (lines) into an array or list
2. Store a string of unknown length (one line) into a variable
3. Read lines of text from a text file

Try to solve each of these aspects separately, and tell us which of them you still have trouble with, so we can offer more specific help on that.

thank you everyone..
i got the solution for this problem.

Regards
Jawad