kolibrios/programs/develop/libraries/kolibri-libc/samples/file_io.c

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

#define READ_MAX 255

static char test_str1[] = "123454567890abcdefghijklmnopqrstufvwxyz";
static char test_str2[READ_MAX];

int main(int argc, char **argv)
{
  int i=0;
  FILE *f;

  //write to file
  debug_printf("Write file...\n");
  f=fopen("testfile.txt","w");

  while(test_str1[i]!='a'){
    fputc(test_str1[i],f);
    i++;
  }
  fclose(f);

  //append to file
  debug_printf("Apend file...\n");
  f=fopen("testfile.txt","a");
  fputs(test_str1+i,f);
  char null_term = '\0';
  fwrite(&null_term, sizeof(char), 1, f);
  printf("Error: %s\n",strerror(errno));
  fclose(f);

  //copy from testfile.txt to copyfile.txt
  debug_printf("Read file...\n");
  f=fopen("testfile.txt","r");
  i=0;
  while((test_str2[i]=fgetc(f))!=EOF && i<READ_MAX){
    fputc(test_str2[i], stdout);
    i++;
  }
  printf("\n%s\n", test_str1);
  if(!strcmp(test_str2, test_str1)){
    puts("TEST: OK!");
  }else{
    puts("TEST: FAIL!");
  }
  fclose(f);
}