C++fstream问题，如何判断一个文件是否为空 C++中fstream如何判断文件不存在
C++fstream\u6d41\u600e\u4e48\u5224\u65ad\u662f\u5426\u771f\u7684\u5230\u4e86\u6587\u4ef6\u7ed3\u5c3e.\u5728\u7ebf\u7b49\u53c2\u8003\u8fd9\u4e2a
#include
#include
using namespace std;
int main()
{
ofstream fcout("a.txt");
fcout<<"fsfd ag\n";
fcout.close();
ifstream fin("a.txt");
if(fin.good())
{
cout<<"\u6253\u5f00\u6210\u529f\n";
char ch;
while(!fin.eof()) //\u8fd9\u91cc
{
ch=fin.get();
cout<<ch;
}
}
fin.close();
fin.open("b.txt");
if(fin.fail())
cout<<"\u6253\u5f00\u5931\u8d25\n";
fin.close();
return 0;
}
#include
#include
using namespace std;
#define FILENAME "D:\\aaa.txt"
int main()
{
fstream file;
file.open(FILENAME,ios::in);
if(!file)
{
cout<<FILENAME<<"\u6ca1\u6709\u88ab\u521b\u5efa";
}
else
{
cout<<FILENAME<<"\u5df2\u7ecf\u5b58\u5728";
}
return 0;
}
}
用peek()函数试探一下文件的第一个字符是否为EOF；
fseek到文件尾然后ftell检查是否为0；
用Win32 API GetFileSize()
#include <iostream>
#include <fstream>
using namespace std;
#define FILENAME "D:\\aaa.txt"
int main()
{
fstream file;
file.open(FILENAME,ios::in);
if(!file)
{
cout<<FILENAME<<"没有被创建";
}
else
{
cout<<FILENAME<<"已经存在";
}
return 0;
}
}
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