在文件 C 中构造 fscanf

Question

In file I need to read some inputs:

this is an example:

8 15
[1,1] v=5 s=4#o
[4,2] v=1 s=9#x

typedef struct{

    int red2;
    int stupac2;
    int visina;
    int sirina;
    char boja[10];

}Tunel;

FILE* fin = fopen("farbanje.txt", "r");
Tunel* tuneli = malloc(sizeof(Tunel)*50);
//    if(fin!=0)
fscanf(fin,"%d %d", &r,&s);
printf("%d %d", r,s);

int p=0;


while (fscanf(fin, "[%d,%d]", &tuneli[p].red2, &tuneli[p].stupac2) == 2)
{

    p++;
}

for(i=0;i<p;i++)
{
    printf("[%d,%d]", tuneli[i].red2, tuneli[i].stupac2);
}

Problem is that it wont read me properly inputs from here: [1,1] v=5 s=4#o Last line where i use printf shows some random numbers.

Answer 1

Last line where i use printf shows some random numbers. ...

The random numbers you see are because the buffers to print were not properly populated yet.

This example shows how to read the file, using fgets() to read a line buffer, then use sscanf() to parse the first two values from the lines. (read in-code comments for a few other tips.)

   int main(void)//minimum signature for main includes 'void'
    {
        int r = 0;
        int s = 0;
        char line[80] = {0};//{initializer for arrays}
        int p = 0;
        Tunel *tuneli = malloc(sizeof(*tuneli)*50);
        if(tuneli)//always test return of malloc before using it
        {       
            FILE *fin = fopen(".\\farbanje.txt", "r");
            if(fin)//always test return of fopen before using it
            {
                fgets(line, sizeof(line), fin);
                sscanf(line, "%d %d", &r, &s);
                while(fgets(line, sizeof(line), fin))
                {
                    sscanf(line, " [%d,%d]", &tuneli[p].red2, &tuneli[p].stupac2);
                    //note space  ^ here to read only visible characters
                    printf("[%d,%d]\n", tuneli[p].red2, tuneli[p].stupac2);//content is now populated corretly
                    p++;
                }
                fclose(fin);//close when finished
            }
            free(tuneli);//free when done to prevent memory leaks
        }
        return 0;
    }

Answer 2

Agree it is better to use fgets But if you want to continue to use your current approach,

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

typedef struct{
  int red2;
  int stupac2;
  int visina;
  int sirina;
  char boja[10];
}Tunel;


int main(){
  int r, s, i;
  FILE*fin=fopen("farbanje.txt", "r");
  if(fin==NULL) {
    printf("error reading file\n");
    return 1;
  }
  Tunel *tuneli=(Tunel*)malloc(sizeof(Tunel)*50);
  fscanf(fin,"%d %d\n", &r,&s);
  printf("%d %d", r,s);

  int p=0;

  while (fscanf(fin, " [%d,%d]%*[^\n]", &tuneli[p].red2, &tuneli[p].stupac2) == 2)
  {
    p++;
  }

  fclose(fin);

  for(i=0;i<p;i++)
  {
    printf("[%d,%d]", tuneli[i].red2, tuneli[i].stupac2);
  }
}