CODEWITHSUNDEEP
cscanfc-strings
kris
kris

Reputation: 385

Reading different types in C from File

I'm trying to read in a file that has different types to read in (integers, chars). This is relatively simple, yet I'm confused on which method to use to read in these different values.

I'm using fgets to make sure the file isn't at the end, i.e;

char line[MAX_CHARS]; 
char ch;
FILE *infile = fopen("file.txt", "r"); 
const int MAX_CHARS = 50;

       while(fgets(line, MAX_CHARS, infile) != NULL)

Given the input;

-Flight one

83, 34

X XX X

X X

-Flight two

....

I want to print the line that starts with a dash, send the integers to a method, and then print the X's and spaces. So, my code for this would be:

if(line[0] == '-')
{
   printf("%s\n", line);
}

else if(2==sscanf(line, "%d%d", &long, &lat))
{
   coordinates(long, lat);
}

I used scanf to try to read the X's and spaces, but it doesn't work at all. getchar() doesn't seem to work either, so should I start over and instead read each char individually instead of a char array?

EDIT: So I did as someone suggested, this is my updated code to read in spaces and X's, but it is clearly not reading right, as it's not going to the next line of X's.

        else
        {
            while(line[++index] != '\0')
            {
                if(line[index]  == ' ')
                {
                  printf("%c", '.');
                }

                else if(line[index] == 'X')
                {
                  printf("%c", '*');

                }
            }
        }

For output;

*Flight one

.......*Flight two

Upvotes: 4

Views: 606

Answers (1)

Mohit Jain
Mohit Jain

Reputation: 30489

scanf(line, " %c", &ch)
/*           ^         */

The space before percent will cause scanf to ignore all whitespace characters (space, tab, newline) if present.

i.e. condition if(ch == ' ') will be always false.

In your question, this is not something that you like, so remove this whitespace.

EDIT Also as suggested by Barak Manos

I think that for the second line you need to scan "%d, %d" instead of "%d%d".

Upvotes: 3

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