Detailed description of how C ++ obtains files

In this article, we will introduce in detail how to obtain files in C ++. For those who have just been familiar with the C ++ programming language, the content introduced in this article can help them solve some of the problems they often encounter in file operations.

 
 

  
  
/*read File*/  
  
  
char *txt = NULL;  
  
  
long txtlen;  
  
  
//seek to file end to calculate file length  
  
  
fseek(fp,0,SEEK_END);  
  
  
txtlen=ftell(fp);  
  
  
//rewind to file start  
  
  
rewind(fp);  
  
  
//read from file  
  
  
txt = new char[txtlen + 1];  
  
  
if (txt != NULL)   
  
  
{  
  
  
fread(txt,sizeof(char),txtlen,fp);  
  
  
txt[txtlen]='\0';  
  
  
fv.setData(txt);  
  
  
}  
  
  
//close file and destroy temp array  
  
  
fclose(fp);  
  
  
if(txt!=NULL)  
  
  
{  
  
  
delete []txt;  
  
  
txt = NULL;  
  
  
} 
 
 

C ++:

 
 

  
  
/*read File*/  
  
  
ifstream in(filesrc);  
  
  
if(in.fail())  
  
  
{  
  
  
printf("open file failed!\n");  
  
  
}  
  
  
else  
  
  
{  
  
  
string strtmp;  
  
  
while (getline(in,strtmp))  
  
  
{  
  
  
fv.getData()+=strtmp;  
  
  
fv.getData()+='\n';  
  
  
}  
  
  
in.close();  
  
  
} 
 
 

The above section describes how to obtain files in C ++.