CODEWITHSUNDEEP
carraysfileline
howdoyouprogram
howdoyouprogram

Reputation: 89

Reading different length lines from a file

I want to be able to make a loop that reads line by line, then captures the digits in the beginning of each line into an int array, and the characters in a 2d character array. I thought I could have a loops like,

while (fscanf(file, "%d %c %c %c", &num, &f, &e, &h)==4){}

but that is if C could read strings. How can I read each line?

Upvotes: 2

Views: 707

Answers (3)

vmp
vmp

Reputation: 2420

      #include <stdio.h>
      #include <stdlib.h>
      int main()
      {
          char matrix[500][500], space;
          int numbers[500], i = 0, j;
          FILE *fp = fopen("input.txt", "r");

          while(!feof(fp))
          {
                fscanf(fp, "%d", &numbers[i]); // getting the number at the beggining
                fscanf(fp, "%c", &space); // getting the empty space after the number
                fgets(matrix[i++], 500, fp); //getting the string after a number and incrementing the counter
          }
        for(j = 0; j < i; j++)
            printf("%d %s\n", numbers[j], matrix[j]);
      }

variable 'i' is counting how many lines you have. If you have more than 500 lines you can change that value or then use a dynamic vector.

Upvotes: 0

yeyo
yeyo

Reputation: 3009

what about this:

    char buf[512];
    int  length = 0;

    while(fgets(&buf[0], sizeof(buf), stdin)) {
        length = strlen(&buf[0]);
        if(buf[length-1] == '\n')
            break
        /* ...
        ... 
        realloc or copy the data inside buffer elsewhere.
        ...*/
    }

/* ... */

Upvotes: 0

Rahul Tripathi
Rahul Tripathi

Reputation: 172458

For reading a line you can use :-

  while ( fgets ( line, sizeof line, file ) != NULL )

or you can try 

  while ((read = getline(&line, &len, fp)) != -1)

Upvotes: 1

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