How to delete a file in file handling in c++ - c++

Question

i made a function that first reads the file and checks if it exists or not and then it removes it after a confirmation but if i do directly like
remove("a.text");
it deletes the file that has the name a.txt but when i use my function
int deletediary()
{
string searchfilename;
cout<<"\nPlease enter the filename to be searched\n";
cin>>searchfilename;
searchfilename.append(".txt");
fileread.open(searchfilename.c_str());
if(!fileread){
cout<<"\nERROR :Either you didn't enter an invalid date or you entered an date with no entry\n\n";
A :
cout<<"Continue to search? (y/n)\n";
if(getch()=='y')
{
modifydiary();
}
else if(getch()=='n')
{
menuview();
}
else
{
cout<<"Enter Correct Option\n";
goto A;
}
}
else{
system("cls");
int i;
B :
cout<<"Are you sure you want to remove this diary entry? (y/n)";
if(getch()=='y')
{
remove(searchfilename.c_str());
}
else if(getch()=='n')
{
menuview();
}
else
{
cout<<"Enter Correct Option\n";
goto B;
}
cout<<"INFO :Deleted!!!";
system("pause");
menuview();
}
it only checks the filename but does not delete it.

Answer 1

In c++17 we have the filesystem library, which gives the tools to easily deal with the problem.
Example:
#include <filesystem>
#include <iostream>
#include <string>
int main()
{
std::string searchfilename;
std::cout << "Please enter the filename to be searched\n";
std::cin >> searchfilename;
try {
if (std::filesystem::remove(searchfilename))
std::cout << "file " << searchfilename << " deleted.\n";
else
std::cout << "file " << searchfilename << " not found.\n";
}
catch(const std::filesystem::filesystem_error& err) {
std::cout << "filesystem error: " << err.what() << '\n';
}
}

Answer 2

You forgot closing the file that you have opened.
So, CLOSE the file and it should work.
Note: The solution worked for #AkhileshSharma and included the comment as an answer to close the question as answered.

Answer 3

When you try to delete a file, you should always handle the return value of remove function immediately. For successful result it returns 0 and for failed, it returns non-zero.
const int result = remove( "no-file" );
if( result == 0 ){
printf( "success\n" );
} else {
printf( "%s\n", strerror( errno ) ); // No such file or directory
}
remove is in the stdio.h file
and strerror is in the string.h
So after your remove function, check to see for what reason it has not been deleted.
The error number is stored in errno variable and strerror can map the error number to a string that tells the reason of failure.
Also you can test the error code and a Linux Terminal if you have it using perror command
> perror 0
OS error code 0: Success
> perror 1
OS error code 1: Operation not permitted
> perror 2
OS error code 2: No such file or directory
> perror 3
OS error code 3: No such process
> perror 4
OS error code 4: Interrupted system call
> perror 5
OS error code 5: Input/output error

Answer 4

//you have to give the path of the file for example(path="C:\\data\\newfolder")
System::IO::DirectoryInfo^ directory = gcnew System::IO::DirectoryInfo(path);
for each(System::IO::FileInfo^ file in directory->GetFiles())
{
//for getting the extension of file(if you want to delete specific extension file)
String^ s = file->Extension;
if (file->Extension == ".png")
{
file->Delete();
}
}