Thread: Need help with strings

Input a line using fgets() with a big buffer. Throw out any lines that are too long and discard the rest of the line.
Look for the string "$--CGA" at the beginning of the line, if you don't find it, discard the line and read the next one.

Check that the line is properly formatted, you have comas and decimal points in the right places, the right number of digits.
If the fields are all fixed width, you can break them out easily. If they are variable width, you need to run a pointer along the line and keep track of where the field you are parsing ends and the next one begins.
Check that the fields are valid.
Do the processing of fields. In your case it's just replacing a and b with +/-.
Use sprintf() or some other function to paste the fields back into your desired format.

You'll get nothing from me, (or many other people too I suspect), until you show your coding attempt at this.

Please refer to the homework guidelines.

There was a point in time when I was at bad in programming as you. If everyone just provided the code to solve the problems I faced with no effort on my part, I would still be as bad in programming as you.

Originally Posted by EspoirBondo

Hint:

In a sentence like this:

Size= 70

$--GSV,x,x,x,x,x,x,x,...*hh
$--GGA,hhmmss.ss,llll.ll,a,yyyyy.yy,b,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh
$--GLC,xxxx,x.x,a,x.x,a,x.x,a.x,x,a,x.x,a,x.x,a*hh
$--GSA,a,a,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x.x,x.x,x.x*hh

You probably think that you have described your problem well. But you have not.

So I am going to ask several questions. You should be able to answer them for yourself. Hopefully, this will lead you to 1) restate the problem better and 2) be able to write some code yourself so you show enough effort to meet the homework policy.

Where did the lines that you show above come from?

Do these lines already exist in a text file? If so, what is the name of the file?

Was the colorization just to help with explanation? Or is it in the input? If so, in what format? HTML commands or ANSI display terminal encoding or some other format.

Did a program(s) generate the lines you have shown above?

If these are a sequence of commands that was typed into the operating system command prompt (or shell), what is the CGA command?

Or was all this the output of one command?

Does your operating system have the ability to redirect standard output from a program to a file? Windows command prompt and Linux shells have this ability.

What does size = 70 mean? Is it part of the input?