标签：read while 就是 out 基本操作 code recover 使用 gets
在C/C++ 讀寫檔案操作比較常見應該是利用 FILE、ifstream、ofstream
在這篇筆記裡頭記錄 FILE、fstream 使用方法及操作
1 #include <iostream> 2 #include <stdio.h> 3 #include <stdlib.h> 4 #include <fstream> 5 6 using namespace std; 7 8 9 int main() 10 { 11 /* 12 r : open for reading 13 rb : open for reading in binary mode 14 w : open for writing 15 wb : open for writing in binary mode 16 r+ : support read and write. the file must exit. 17 w+ : it like r+ funciton that will recover the file with same file name if file name exit. 18 */ 19 FILE *pFile; 20 21 /* open and create the file */ 22 pFile = fopen("temp.txt", "w+"); 23 char buffer[] = "write string test"; 24 char *rd_buffer; 25 /* write the buffer to text file */ 26 fwrite(buffer, sizeof(char), sizeof(buffer), pFile); 27 /* close file */ 28 fclose(pFile); 29 30 pFile = fopen("temp.txt", "r+"); 31 /* assign read buffer size */ 32 rd_buffer = (char*)malloc(sizeof(char)* sizeof(buffer)); 33 /* read file data to read file */ 34 fread(rd_buffer, sizeof(char), sizeof(buffer), pFile); 35 cout << rd_buffer << endl; 36 /* close file */ 37 fclose(pFile); 38 39 system("pause"); 40 return 0; 41 }
在開始進行讀寫之前有一段註解，裡頭主要標示在fopen開檔之後必須填入的參數代表啥意思
/* r : open for reading rb : open for reading in binary mode w : open for writing wb : open for writing in binary mode r+ : support read and write. the file must exit. w+ : it like r+ funciton that will recover the file with same file name if file name exit. */
w/r 就很簡易的只是 : 只能讀 / 只能寫，wb/rb 多個b表示2進制的檔案操作
r+/w+ 多+ : 在操作上就是能讀能寫但是 r+ 有囑意是這個檔案必須存在
在讀檔案的時，有時需求是直接讀一行，利用feof函式去判斷是否讀到最後一行
while (!feof(pFile)) { fgets(data, 500, pFile); cout << data; }
以下是fsteram 檔案基本操作，之後有遇到比較困難的應用在來上頭記錄
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <string.h> 4 #include <iostream> 5 #include <fstream> 6 7 using namespace std; 8 9 int main() 10 { 11 fstream file; 12 13 /* write file operation */ 14 file.open("temp.txt", ios::out); 15 file << "write data to file" << endl; 16 file << "fstream write file to test" << endl; 17 file << "fstream line 1 test" << endl; 18 file << "fstream line 2 test" << endl; 19 file << "fstream line 3 test" << endl; 20 file << "fstream line 4 test" << endl; 21 file << "fstream line 5 test" << endl; 22 file << "fstream line 6 test" << endl; 23 file << "fstream line 7 test" << endl; 24 file << "fstream line 8 test" << endl; 25 file.close(); 26 27 /* read file operation */ 28 file.open("temp.txt", ios::in); 29 while (!file.eof()){ 30 char buf[200]; 31 file.getline(buf, 200); 32 cout << buf << endl; 33 } 34 file.close(); 35 36 system("pause"); 37 return 0; 38 }
标签：read while 就是 out 基本操作 code recover 使用 gets
原文地址：https://www.cnblogs.com/ollie-lin/p/10274553.html
