PHP file itself

  //The operation of the file itself
 //copy() copies the file
 //unlink() deletes the file
 //ftruncate() truncates the file to the specified length
 //rename() Rename a file or directory
 if(copy("data.txt","data_bak.txt")){//Copy file example
 echo "File copied successfully";
 }else{
 echo " File copy failed";
 }
 if(file_exists("data_bak.txt")){//Delete file instance
 if(unlink("data_bak.txt")){
 echo "File deleted successfully ";
 }else{
 echo "File deletion failed";
 }
 }else{
 echo "The target file does not exist";
 }
 if(rename("file.jpg","file.txt")){//Rename file instance
 echo "File rename successful";
 }else{
 echo "File rename failed ";
 }
 $fp=fopen("data_bak.txt","r+") or die("File opening failed");
 if(ftruncate($fp,1024)){
 echo "File interception successful";
 }else{
 echo "File interception failed";
 }
 fclose($fp);
 ?>

PHP