c/c++读写文件

// writing on a text file
#include <fstream>
using namespace std;
int main () {
ofstream out("out.txt");
if (out.is_open())
{
out << "This is a line.\n";
out << "This is another line.\n";
out.close();
}
return 0;
}
//结果: 在out.txt中写入：
This is a line.
This is another line

// reading a text file
#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>

int main () {
char buffer[256];
ifstream in("out.txt");
if (! in.is_open())   {
cout << "Error opening file"; exit (1);
}
while (!in.eof() ) {
in.getline (buffer,100);
cout << buffer << endl;
}
return 0;
}
//结果 在屏幕上输出
This is a line.
This is another line

#include <stdio.h>

int main()
{
FILE * fp;
int i;
char * path="./testout.txt";

fp = fopen(path, "w");
if(fp == NULL)
{
perror("open error");
return 1;
}

char arr[5]={'l','i','n','u','x'};
for(i=0; i<5;i++)
{
if(fputc(arr[i],fp) == EOF)
{
perror("fgetc error");
return 1;
}
}

printf("\nputc suceesful\n");
fclose(fp);
return 1;
//结果: 在testout.txt中写入：
linux
}

#include <stdio.h>

int main()
{
FILE * fp;
int i;
char * path="./testout.txt";
int ch;

fp = fopen(path, "r");
if(fp == NULL)
{
perror("open error");
return 1;
}
printf("output data in test.txt\n");
for(i=0; i<5;i++)
{
ch = fgetc(fp);
if(ch == EOF)
{
perror("fgetc error");
return 1;
}
else
{
printf("%c", (char)ch);
}
}

printf("\nget suceesful\n");
fclose(fp);
return 1;
}
}
//结果在终端打印出linux