working with strings

lab04/main.cpp

@@ -3,6 +3,9 @@
 #include <iomanip>
 #include <bitset>
 #include <cstddef>
+#include <fstream>
+#include <cstring>
+#include <cctype>
 
 using namespace std;
 
@@ -104,6 +107,29 @@ struct Student {
     Student* monitor;       // 8 áàéò (äëÿ 64-áèòíîé ñèñòåìû)
 };
 
+
+bool is_valid_filename(const char* name) {
+    const char* forbidden = "*\"<>?|";
+    for (size_t i = 0; i < strlen(name); i++) {
+        if (strchr(forbidden, name[i])) return false;
+    }
+
+    // Ïðîâåðêà äâîåòî÷èÿ
+    const char* colon = strchr(name, ':');
+    if (colon) {
+        if (colon - name != 1 || !isalpha(name[0]) || *(colon + 1) != '\\')
+            return false;
+    }
+
+    // Ïðîâåðêà ðàñøèðåíèÿ
+    const char* dot = strrchr(name, '.');
+    if (dot) {
+        if (strncasecmp(dot, ".txt", 4) != 0) return false;
+    }
+
+    return true;
+}
+
 int main() {
     // Òåñòèðîâàíèå ÷èñåë èç ëåêöèîííîãî ñëàéäà
     uint16_t a = 0x4d2;    // 1234 â äåñÿòè÷íîé
@@ -185,6 +211,52 @@ int main() {
 
     cout << endl;
 
+
+    char filename[256];
+    cout << "Enter file name: ";
+    cin.getline(filename, 256);
+
+    if (!is_valid_filename(filename)) {
+        cerr << "Incorrect file name!";
+        return 1;
+    }
+
+    // Äîáàâëåíèå .txt ïðè îòñóòñòâèè ðàñøèðåíèÿ
+    if (!strrchr(filename, '.')) {
+        strcat(filename, ".txt");
+    }
+
+    // Çàãðóçêà ôàéëà
+    ifstream file(filename, ios::binary | ios::ate);
+    if (!file) {
+        cerr << "Error open file!";
+        return 1;
+    }
+
+    streamsize size = file.tellg();
+    file.seekg(0, ios::beg);
+    char* buffer = new char[size + 1];
+    file.read(buffer, size);
+    buffer[size] = '\0';
+
+    // Ïîèñê ïîäñòðîêè
+    char query[256];
+    cout << "Enter line for find: ";
+    cin.getline(query, 256);
+
+    int count = 0;
+    const char* ptr = buffer;
+    while ((ptr = strstr(ptr, query)) != nullptr) {
+        count++;
+        ptr += strlen(query);
+    }
+
+    cout << "number of occurrences: " << count << endl;
+
+    delete[] buffer;
+
+    cout << endl;
+
     char op;
 
     cout << "Enter first operand (hex): ";
@@ -204,6 +276,7 @@ int main() {
             return 1;
     }
 
+
     // Âûâîä â hex
     cout << "\nResult (hex): ";
     print_in_hex(a);