Zh#1

#include "stdafx.h"
#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string>

#pragma warning (disable:4996)

bool CreateNewFile(char * FileName, int stQuantity);

bool PrintFile(char * FileName);

bool WriteNewFileBySgroup(char * readFileName, char * writeFileName, char* group);

struct Student {
    char group[30];
    char fam[50];
    int stip;
};

int main()
{
    int StQuantity(0);
    char Sfile[100], ESfile[100];
    printf("Input Students file filename: ");
    gets_s(Sfile);
    printf("Input quantity of students: ");
    scanf("%d", &StQuantity);
    printf("\n");
    getchar();

    bool checkStatus = CreateNewFile(Sfile, StQuantity);

    if (checkStatus) {
        printf("File was created!\n");
    }
    else {
        printf("Error occured!\n");
        return -1;
    }

    checkStatus = PrintFile(Sfile);
    if (checkStatus) {
        printf("File was read!\n");
    }
    else {
        printf("Error occured!\n");
        return -1;
    }

    printf("\n");

    char group[30];

    printf("Input specified group of students: ");
    scanf("%s", &group);

    printf("\nInput new students file filename: ");
    scanf("%s", &ESfile);

    checkStatus = WriteNewFileBySgroup(Sfile, ESfile, group);
    if (checkStatus) {
        printf("File was created!\n");
    }
    else {
        printf("Error occured!\n");
        return -1;
    }

    checkStatus = PrintFile(ESfile);
    if (checkStatus) {
        printf("File was read!\n");
    }
    else {
        printf("Error occured!\n");
        return -1;
    }

    system("pause");

    return 0;
}

bool CreateNewFile(char * FileName, int stQuantity) {
    FILE * fileStream = fopen(FileName, "wb");
    if (!fileStream) {
        return false;
    }
    Student st;
    for (int i = 0; i < stQuantity; i++) {
        printf("Input student group: ");
        scanf("%s", &st.group);
        printf("Input fam of student: ");
        scanf("%s", &st.fam);
        printf("Input stip of student: ");
        scanf("%d", &st.stip);
        fwrite(&st, sizeof(st), 1, fileStream);
        printf("\n");
    }
    fclose(fileStream);
    return true;
}

bool PrintFile(char * FileName) {
    FILE * fileStream = fopen(FileName, "rb");
    if (!fileStream) {
        return false;
    }
    Student st;
    while (fread(&st, sizeof(st), 1, fileStream)) {
        printf("%s : %s : %d\n", st.group, st.fam, st.stip);
    }
    fclose(fileStream);
    return true;
}

bool WriteNewFileBySgroup(char * readFileName, char * writeFileName, char* group) {
    FILE * readFileStream = fopen(readFileName, "rb");
    FILE * writeFileStream = fopen(writeFileName, "wb");

    if ((!readFileStream) || (!writeFileStream)) {
        return false;
    }

    Student st;
    while (fread(&st, sizeof(st), 1, readFileStream)) {
        if (strcmp(st.group, group) == 0 && st.stip > 0) {
            fwrite(&st, sizeof(st), 1, writeFileStream);
        }
    }

    fclose(readFileStream);
    fclose(writeFileStream);
    return true;
}