Four File Handling Hacks which every C/C++ Programmer should know
We will discuss about four file hacks listed as below-
- Rename – Rename a file using C/C++
- Remove – Remove a file using C/C++
- File Size – Get the file size using C/C++
- Check existence – Check whether a file exists or not in C/C++
C++
// C++ Program to demonstrate the // four file hacks every C/C++ must know // Note that we are assuming that the files // are present in the same file as the program // before doing the below four hacks #include <iostream> #include <stdlib.h> using namespace std; // A Function to get the file size unsigned long long int fileSize( const char *filename) { // Open the file FILE *fh = fopen (filename, "rb" ); fseek (fh, 0, SEEK_END); unsigned long long int size = ftell (fh); fclose (fh); return size; } // A Function to check if the file exists or not bool fileExists( const char * fname) { FILE *file; if (file = fopen (fname, "r" )) { fclose (file); return true ; } return false ; } // Driver Program to test above functions int main() { cout << fileSize( "Passwords.txt" ) << " Bytes\n" ; cout << fileSize( "Notes.docx" ) << " Bytes\n" ; if (fileExists( "OldData.txt" ) == true ) cout << "The File exists\n" ; else cout << "The File doesn't exist\n" ; rename ( "Videos" , "English_Videos" ); rename ( "Songs" , "English_Songs" ); remove ( "OldData.txt" ); remove ( "Notes.docx" ); if (fileExists( "OldData.txt" ) == true ) cout << "The File exists\n" ; else cout << "The File doesn't exist\n" ; return 0; } // This code is contributed by sarajadhav12052009 |
C
// A C Program to demonstrate the // four file hacks every C/C++ must know // Note that we are assuming that the files // are present in the same file as the program // before doing the below four hacks #include<stdio.h> #include<stdlib.h> #include<stdbool.h> // A Function to get the file size unsigned long long int fileSize( const char *filename) { // Open the file FILE *fh = fopen (filename, "rb"); fseek (fh, 0, SEEK_END); unsigned long long int size = ftell (fh); fclose (fh); return (size); } // A Function to check if the file exists or not bool fileExists( const char * fname) { FILE *file; if (file = fopen (fname, "r")) { fclose (file); return ( true ); } return ( false ); } // Driver Program to test above functions int main() { printf ("%llu Bytes\n", fileSize("Passwords.txt")); printf ("%llu Bytes\n", fileSize("Notes.docx")); if (fileExists("OldData.txt") == true ) printf ("The File exists\n"); else printf ("The File doen't exist\n"); rename ("Videos", "English_Videos"); rename ("Songs", "English_Songs"); remove ("OldData.txt"); remove ("Notes.docx"); if (fileExists("OldData.txt") == true ) printf ("The File exists\n"); else printf ("The File doesn't exist\n"); return 0; } |
Output: Screenshot before executing the program :
Screenshot after executing the program :
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