C Exercises: File read and write using variable

C File Handling : Exercise-17 with Solution

Write a program in C to read from a file into a variable and write a variable's contents into a file.

Sample Solution:

C Code:

#include <stdio.h>

int main(int argc, char **argv) {
  FILE *in, *out;
  int c, str;
   
  in = fopen("i.txt", "r");
  if (!in) {
    fprintf(stderr, "Error opening i.txt for reading.\n");
    return 1;
  }
  out = fopen("o.txt", "w");
  if (!out) {
    fprintf(stderr, "Error opening output.txt for writing.\n");
    fclose(in);
    return 1;
  }
  while ((c = fgetc(in)) != EOF) {
    fputc(c, out);
  }
  fclose(out);
  fclose(in);
  return 0;
}

Sample Output:

Error opening i.txt for reading.

Flowchart:

C Programming Code Editor:

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