Функции поиска в бинарном файле - C (СИ) - Ответ 15336813

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
const char data[50] ="data.dat";
const char strs[50] ="structures.txt";
typedef struct worker
{
    char surname[30];
    char name[10];
    char position[30];
    unsigned int year;
}worker_t;
worker_t * getStruct(worker_t * w, char * fio, const char * file)
{
  FILE *f;
  int n, i;
  if((f = fopen(file, "rb")) == NULL)
  {
    printf("%s", strerror(errno));
    return NULL;
  }
  fread(&n, sizeof(int), 1, f);
  for( i = 0; i < n; i++)
  {
    fread(w, sizeof(worker_t), 1, f);
    if(strcmp(w->surname, fio)==0 )
    { 
      fclose(f);
      return w;
    }
  }
  fclose(f);    
  return NULL;
}
worker_t * getStructByNum(worker_t * w, int c, const char * file)
{
  FILE *f;
  int n;
  if((f = fopen(file, "rb")) == NULL)
  {
    printf("%s", strerror(errno));
    return NULL;
  }
  fread(&n, sizeof(int), 1, f);
  if(n<c)return NULL;
  if (fseek(f, sizeof(int)+(c-1)*sizeof(worker_t),SEEK_SET)==EOF)
  { return NULL; }
  fread(w, sizeof(worker_t), 1, f); 
  fclose(f);    
  return w;
}
int main(void)
{   
    int n, i;
    FILE *fp, *out;
    if ((fp = fopen(strs, "r")) == NULL)
    {
        printf("%s", strerror(errno));
        return 1;
    }
    fscanf(fp, "%d", &n);
    worker_t *people;
    people = (worker_t*) malloc (n*sizeof(worker_t));
    i=0;
    while (fscanf(fp, "%s %s %s %d", people[i].surname, people[i].name, 
    people[i].position, &people[i].year)!=EOF)
    {
        printf("%s %s\t%s\t%d\n", people[i].surname, people[i].name, people[i].position, people[i].year);
        i++;
    }
 
    if(!feof(fp)){printf("%s", strerror(errno)); return 1;}
    fclose(fp);
    if ((out = fopen(data, "wb")) == NULL)
    {
        printf("%s", strerror(errno));
        return 1;
    }
    fwrite(&n, sizeof(int), 1, out);
    for (i=0; i<n; i++)
        fwrite(&people[i], sizeof(struct worker), 1, out);
    fclose(out);
    people = getStruct(people, "Petrov", data);
    printf("\n%s %s\t%s\t%d\n", people->surname, people->name, 
    people->position, people->year);
    people=getStructByNum(people, 2, data);
    printf("\n%s %s\t%s\t%d\n", people->surname, people->name, 
    people->position, people->year);
    free(people);
    return 0;
}