Reading both string and integer from a text file

Question

Let say I have a file looks like this

51.41 52.07 52.01 51.22 50.44 49.97 Coal Diggers
77.26 78.33 78.29 78.12 77.09 75.74 Airplane Flyers
31.25 31.44 31.43 31.09 31.01 30.92 Oil Fracting and Pumping
52.03 12.02 12.04 22.00 31.98 61.97 Big Bank
44.21 44.32 44.29 43.98 43.82 43.71 Rail Container Shipping
93.21 93.11 93.02 93.31 92.98 92.89 Gold Bugs

I want to read this file word using fscanf to put the numbers in float arrays and words in an array of strings. But, after few hours of strenuous thinking, I still can't figure out how to resolve this thing.

void dataInsert (COMPANY* company1, COMPANY* company2, COMPANY* company3, COMPANY* company4, COMPANY* company5, COMPANY* company6)
{
//Function Declaration
FILE* spData;
float number;
char* name[20];

//Statement
if ((spData = fopen("dataFile","r")) == NULL)
{
    fprintf(stderr, "ERROR OPENING!!");
    exit (1);
}

int i = 0;
int numCount = 0;
int lineCount = 0;
while (fscanf(spData, "%f", &number) != EOF)
{
    if(isdigit(number))
    {
        if (lineCount == 0)
        {
            company1 -> stock_price[i] = number;
        }
        else if (lineCount == 1)
        {
            company2 -> stock_price[i] = number;
        }
        else if (lineCount == 2)
        {
            company3 -> stock_price[i] = number;
        }
        else if (lineCount == 3)
        {
            company4 -> stock_price[i] = number;
        }
        else if (lineCount == 4)
        {
            company5 -> stock_price[i] = number;
        }
        else if (lineCount == 5)
        {
            company6 -> stock_price[i] = number;
        }

        numCount++;
        i++;
        if (numCount == 6)
        {
            lineCount++;
            numCount = 0;
            i = 0;
        }
    }
}//while
fclose (spData);
}//dataInsert

I don't know what to do with strings at the end of each line. I want to put those string in structure company -> name[10]. Those data are in a text file.

Answer 1

Instead of using fscanf I would recommend using fgets to get the line. Then use sscanf on that line to get the numeric values, and search for the first alphabetic character to know where the string starts (using e.g. strspn).

Something like this:

char line[256];

while (fgets(line, sizeof(line), fp) != NULL)
{
    /* Get the numbers */
    float numbers[6];
    sscanf(line, "%f %f %f %f %f %f",
        &numbers[0], &numbers[1], &numbers[2],
        &numbers[3], &numbers[4], &numbers[5]);

    /* Where do the numbers end... */
    size_t numbers_end = strspn(line, "1234567890. \t");

    /* And get the name */
    char *name = line + numbers_end;

    /* Do something with the numbers and the name */
}

Answer 2

If the file is in exactly that format, you can use scanf() easily. Here's some code to get you started; I haven't tested this and you need to fill in a few missing things.

#include <ctypes.h>  // for isspace()
#include <stdio.h> // for scanf(), getchar(), and EOF

char c2d[MAX_LINES][MAX_LENGTH_STRING_PER_LINE];
char *pstr;
float f2d[MAX_LINES][6]; // 6 floats per line
float *p;
int c, current_line_number;
char ch;
FILE *input;

input = fopen(...);
if (!input)
    ... handle the error

for (current_line_number = 0; ; ++current_line_number)
{
    // handle each line of input

    // first read 6 float values
    p = f2d + current_line_number;
    c = fscanf(input, "%f %f %f %f %f %f", p + 0, p + 1, p + 2, p + 3, p + 4, p + 5);
    if (c != 6)
        ... handle the error here

    // next grab string; stop at '<' or end of line or EOF
    pstr = c2d + current_line_number;
    for (;;)
    {
        ch = fgetc(input);
        if (ch == EOF || ch == '<' || ch == '\n')
        {
            *pstr = '\0';
            break;
        }
        *pstr++ = ch;
    }
    if (ch == '<')
    {
        // char was '<' so throw away rest of input line until end of line
        for (;;)
        {
            if (ch == EOF || ch == '\n')
                break;
            ch = fgetc(input);
        }
    }
    for (;;)
    {
        // eat up any white space, including blank lines in input file
        if (ch == EOF || !isspace(ch))
            break;
        ch = fgetc(input);
    }
    // once we have hit end of file we are done; break out of loop
    if (ch == EOF)
        break;
}

fclose(input);

I didn't use scanf() to read the string at the end of the line because it stops when it hits white space, and your string values have spaces in them.

If the input file isn't always six float values, you will need to write code to call scanf() one float at a time until you hit something that doesn't parse as a float, and you will need to make the array of floats wide enough to handle the largest number of floats you will permit per line.

Good luck.