从C格式的ASCII格式文件中解析数据

Question

I am trying to do what's been done here Read co-ordinates from a txt files using C Program . The data that I am trying to input is in this format:

f 10 20 21
f 8 15 11
. . .  .
f 11 12 25

The only difference in my point structure is that I have a an extra char to store the letter in the first column (which may or may not be the letter f). I guess im either declaring my char wrong, or I'm calling it in printf incorrectly. Either way, I only get the first line read and then my program terminates. Any ideas ?

Here is my MWE below

#define FILEPATHtri "/pathto/grid1DT.txt"
#define FILEPATHorg "/pathto/grid1.txt"
#define MAX  4000

#include <stdio.h>
#include <stdlib.h>
#include "math.h"

typedef struct
{    
    float x;
    float y;
    float z;
    char t[1];
}Point;

int main(void) {

    Point *points = malloc( MAX * sizeof (Point) ) ;

    FILE *fp ;
    fp = fopen( FILEPATHtri,"r");

int i = 0;

while(fscanf(fp, "%s %f %f %f ", points[i].t, &points[i].x, &points[i].y, &points[i].z ) == 4 )
{
    i++;
}
fclose(fp);

int n;


for (n=0; n<=i; n++){

    printf("%c  %2.5f %2.5f %2.5f \n", points[i].t, points[n].x, points[n].y, points[n].z ); }


    printf("There are i = %i  points in the file \n And I have read n = %i  points ",i,n);

return 0;

}

Answer 1

Since there's only 1 char in there, not a string just use a single char in your code:

    char t;
}Point;

Then when you read it in:

while(fscanf(fp, "%c %f %f %f ", &points[i].t, &points[i].x, &points[i].y, &points[i].z ) == 4 )
{

I'll note that having an array of 1 char, at the end of a structure, sets you up for the struct hack which might not have been your intentions... A good reason to use just char t instead of char t[1]

Also this line:

for (n=0; n<=i; n++){

Should be

for (n=0; n<i; n++){

One last note... if you wanted to print the character out that you read in the prints at the bottom, you should be using n :

// note your previous code was points[i].t
printf("%c  %f %f %f \n", points[n].t, points[n].x, points[n].y, points[n].z ); }

Answer 2

Check this

  while(fscanf(fp, "%c %f %f %f ", points[i].t, &points[i].x, &points[i].y, &points[i].z ) == 4 )
    {
    i++;
}
fclose(fp);

int n;


for (n=0; n<i; n++){

    printf("%c  %2.5f %2.5f %2.5f \n", points[n].t, points[n].x, points[n].y, points[n].z ); }


    printf("There are i = %i  points in the file \n And I have read n = %i  points ",i,n);
getch();
return 0;

}

modification are since only a single character is read %s modified to %c also in printf its not points[i].t its points[n].t . Also the limit checking in for loop is also corrected to n<i