reading information in a file

[viadd]

hey i'm tyring to prep for an exam and i'm really unsure of what i'm doing

we have to write a programthat will read a text file and then get the program to preform specific actions based on the information in the file,

i can get the program to read the file no problem but i really don't know how to get it to read the information so that it can preform different tasks for the different information given (the file contains both words and figures)

any help or advice that anyone could offer would be much appreciated!!

p.s. sorry if this is a bit of an ameturish question but i've tried books and other sites on the net and i'm getting nowhere

[Banfa]

Once you have read the the from the file then you need to parse that text.

Suppose that you read the following line from the file into an array of characters called line.

print: Hello World

OK and suppose that the program has to print anything that follows the print: statement to the screen you could achieve that this way

char line[MAX_LINE];
 
/* file opened and line read here */
 
if ( strncmp("print:", line, 6) == 0 )
{
    puts( &line[6] );
}
else ... /* Look for other commands in the file */
 
 

You could also look up the help for strtok although this function has some pit falls of it's own.

[viadd]

I've gotten the file to print the informaton in it but its not just characters its numbers as well.

This is an example of information that would be in a the file.

2000 Airbus 200
1999 Boeing 100
1998 Boeing 200
2004 Airbus 300
2003 Boeing 250
2001 Airbus 250
2002 Boeing 200
2003 Boeing 150

I've got to sort it by the year of construction type of plane and number of passengers using an algorithm that I've been given.

The problem is that I don't even know where to begin, how can i get the program to differentate between the two different types of figures and the type of plane?

Any help at all would be great as I'm completely lost!!

[iLL eFFect]

u can do this in two ways:
1. if u are writin the file as well then u can feed the data while writin, in a structure and write in the file.
2. u can write character by charcter and look for numeric values. soon as u find it look for alphabet and then numeric value again.

does this solve ur problem?

[Banfa]

In that case you should probably look up the function

strtoul (or strtol)

This function converts text based digits into an integer and returns a pointer to where it stopped converting the string, allowing you to continue parsing from there.

[viadd]

u can do this in two ways:
1. if u are writin the file as well then u can feed the data while writin, in a structure and write in the file.
2. u can write character by charcter and look for numeric values. soon as u find it look for alphabet and then numeric value again.

does this solve ur problem?

The problem is that i don't really know how to do those things, but they sound like the sort of direction i want to be heading in.

That stroul function looks pretty promising,.Thanks Banfa I'm gonna give it a go now and see if I can get it to work for what I want to do.