problem in writing to a file
Guys I wrote the following code for implementing a phonebook in c++ What I am doing is first take input from three files containing names, address and phone number(u may not look at the entire code) just look at the bottom
Now I give user to add contacts to add during runtime and these values are stored in a class. Now I erase the files containing names, address and numbers and write new data into them using ofstream which will be retrieved when user again runs the "phonebook"
however i am not able to see any input into the files after program has run once and I added a few values during the runtime. Can someone help me? Thanks in advance
#include<iostream>//Include Header Files
#include<cstdlib>
#include<fstream>
#include<string>
using namespace std;
class contact{
public:
string name;//ALL CLASS VARIABLES ARE PUBLIC
int phonenumber;
string address;
contact(){//Constructor
name= "Noname";
phonenumber= 0;
address= "Noaddress";
}
};
int main(){
contact *d;
d= new contact[200];
string name,add;
int choice,modchoice,k=0;//Variable for switch statement
int phno,phno1;
int i=0;
int initsize=0, i1=0;//i is declared as a static int variable
bool flag=false,flag_no_blank=false;
//TAKE DATA FROM FILES.....
//We create 3 files names, phone numbers, Address and then abstract the data from these files first!
fstream f1;
fstream f2;
fstream f3;
string file_input_name;
string file_input_address;
int file_input_number;
f1.open("./names");
while(f1>>file_input_name){
d[i].name=file_input_name;
i++;
}
initsize=i;
f2.open("./numbers");
while(f2>>file_input_number){
d[i1].phonenumber=file_input_number;
i1++;
}
i1=0;
f3.open("./address");
while(f3>>file_input_address){
d[i1].address=file_input_address;
i1++;
}
cout<<"\tWelcome to the phone Directory\n";//Welcome Message
do{
//do-While Loop Starts
cout<<"Select :\n1.Add New Contact\n2.Update Existing Contact\n3.Display All Contacts\n4.Search for a Contact\n5.Delete a Contact\n6.Exit PhoneBook\n\n\n";//Display all options
cin>>choice;//Input Choice from user
switch(choice){//Switch Loop Starts
case 1:{
i++;//increment i so that values are now taken from the program and stored as different variables
i1++;
do{
cout<<"\nEnter The Name\n";
cin>>name;
if(name==" "){cout<<"Blank Entries are not allowed";
flag_no_blank=true;
}
}while(flag_no_blank==true);
flag_no_blank=false;
d[i].name=name;
cout<<"\nEnter the Phone Number\n";
cin>>phno;
d[i1].phonenumber=phno;
cout<<"\nEnter the address\n";
cin>>add;
d[i1].address=add;
i1++;
i++;
break;//Exit Case 1 to the main menu
}
case 2: {
cout<<"\nEnter the name\n";//Here it is assumed that no two contacts can have same contact number or address but may have the same name.
cin>>name;
int k=0,val;
cout<<"\n\nSearching.........\n\n";
for(int j=0;j<=i;j++){
if(d[j].name==name){
k++;
cout<<k<<".\t"<<d[j].name<<"\t"<<d[j].phonenumber<<"\t"<<d[j].address<<"\n\n";
val=j;
}
}
char ch;
cout<<"\nTotal of "<<k<<" Entries were found....Do you wish to edit?\n";
string staticname;
staticname=d[val].name;
cin>>ch;
if(ch=='y'|| ch=='Y'){
cout<<"Which entry do you wish to modify ?(enter the old telephone number)\n";
cin>>phno;
for(int j=0;j<=i;j++){
if(d[j].phonenumber==phno && staticname==d[j].name){
cout<<"Do you wish to change the name?\n";
cin>>ch;
if(ch=='y'||ch=='Y'){
cout<<"Enter new name\n";
开发者_运维百科 cin>>name;
d[j].name=name;
}
cout<<"Do you wish to change the number?\n";
cin>>ch;
if(ch=='y'||ch=='Y'){
cout<<"Enter the new number\n";
cin>>phno1;
d[j].phonenumber=phno1;
}
cout<<"Do you wish to change the address?\n";
cin>>ch;
if(ch=='y'||ch=='Y'){
cout<<"Enter the new address\n";
cin>>add;
d[j].address=add;
}
}
}
}
break;
}
case 3 : {
cout<<"\n\tContents of PhoneBook:\n\n\tNames\tNumbers\tAddresses\n";
for(int t=0;t<=i;t++){
if(d[t].name=="Noname") continue;
cout<<".\t"<<d[t].name<<"\t"<<d[t].phonenumber<<"\t"<<d[t].address<<"\n";
}
cout<<"\n\n\n\n";
break;
}
case 4:{
cout<<"Enter a name to search\n";
cin>>name;
cout<<"\n\nSearching.........\n\n";
for(int j=0;j<=i;j++){
if(d[j].name==name){
k++;
cout<<k<<".\t"<<d[j].name<<"\t"<<d[j].phonenumber<<"\t"<<d[j].address<<"\n\n";
int val=j;
}
}
cout<<"\nA total of "<<k<<" contact names were found having the name"<<name;
break;
}
case 6:{
cout<<"\n\nClosing the phonebook...Visit Again\n";
flag=true;
break;
}
case 5: {
cout<<"\nEnter the contact-name\n";//Here it is assumed that no two contacts can have same contact number or address but may have the same name.
cin>>name;
int k=0,val;
cout<<"\n\nSearching.........\n\n";
for(int j=0;j<=i;j++){
if(d[j].name==name){
k++;
cout<<k<<".\t"<<d[j].name<<"\t"<<d[j].phonenumber<<"\t"<<d[j].address<<"\n\n";
val=j;
}
}
char ch;
cout<<"\nTotal of "<<k<<" Entries were found....Do you wish to delete?\n";
if(k==0) break;
string staticname;
staticname=d[val].name;
cin>>ch;
if(ch=='y'|| ch=='Y'){
cout<<"Which entry do you wish to delete ?(enter the old telephone number)\n";
cin>>phno;
for(int j=0;j<=i;j++){
if(d[j].phonenumber==phno && staticname==d[j].name){
val=j;
}
}
for(int j=val;j<=i-1;j++){
d[j].name=d[j+1].name;
d[j].phonenumber=d[j+1].phonenumber;
d[j].address=d[j+1].address;
}
d[i].name="Noname";
d[i].phonenumber=0;
d[i].address="Noaddress";
}
break;
}
}
}
while(flag==false);
std::ofstream f4("./names");
f4.close();
std::ofstream f5("./numbers");
f5.close();
std::ofstream f6("./address");
f6.close();
f1.close();
f2.close();
f3.close();
ofstream f7,f8,f9;
f7.open("names");
f8.open("numbers");
f9.open("address");
int y=0;
string w;
w=d[0].name;
while(f7<<w && y<=i){
if(w=="Noname") y++; continue;
y++;
w=d[y].name;
}
y=0;
int v;
v=d[0].phonenumber;
while(f8<<v && y<=i){
if(v==0){y++; continue;}
y++;
v=d[y].phonenumber;
}
y=0;
string u;
u=d[0].address;
while(f9<<u && y<=i ){
if(u=="Noaddress"){
continue;
y++;
}
y++;
u=d[y].address;
}
return 0;
}
Does C++ handle I/O errors automatically? Psychically? If not, then where are your error-return handlers? Just askin'.
EDIT in response to the OP's comment: Yes, I understand, but ordinarily if data is not being written to the file, the file system returns an error code that tries to tell you why it was not written. But you decided to ignore what the file system had to say. My question, which I'd hoped would give you a hint, should have been:
"If you don't check the file-write-call return codes, you will have a good, long hike trying to debug your program. Please check those error return codes and tell us what they are. This is standard and required programming practice, after all, and if you don't follow standard, required practice then your only hope is to consult the gypsy fortune-teller on the corner.
"SO: what are the codes being returned from each and every file-I/O call?"
Try that and tell us more. And thanks for the downvote: I needed that.
btw.
while(f7<<w && y<=i){
if(w=="Noname")
y++; // <- proper indention is king
continue;
y++; // <- never reached
w=d[y].name; // <- never reached
}
while(f8<<v && y<=i){
if(v==0) {
y++;
continue;
}
y++;
v=d[y].phonenumber;
}
while(f9<<u && y<=i ){
if(u=="Noaddress") {
continue;
y++; // <- never reached
}
y++;
u=d[y].address;
}
I can see why you are frustrated, coder. This is frustrating code.
while(flag==false)(as per Jonathans comment this isn't as blatantly bad as it appeared. It still is bad that it is even hard to judge the real junk from the rest of the mess... :)
WTF? Just don't hit '6' to exit, or you will be frying your CPU for free
It was still burning 100% of CPU and filling /tmp at a hazardous pace anyway. I guess, it is not called an infinite loop (because it exits as soon as the filesystem is full). Thank god, /tmp is on tmpfs (size 4g) and I have 8g of ram available :)
Storing the names, numbers and addresses in separate files... hm probably a good idea.
One test run I had it writing 3.7G to address :) ("NoaddressNoaddressNoaddressNoaddressNo....") Just sweet to make it crash because on load, the buffer to receive address in (obviously called d) is precisely 200 records.
Frankly this code should move to TheDailyWTF. Pronto Pronto!
This code can not be fixed. Period
There are a multitude of things wrong with this program. Lets try to fix a few for a start and then build on that.
Firstly, what does a name look like? Does it have a space, like "Fred Jones" or maybe a comma like "Jones,Fred". Maybe many parts like "Chan Kong Sang".
If you permit spaces, then you can't read it in with "<<". Maybe you can put one name per line and read it in with getline().
Try writing a small program that just reads in names and stores them. You can create the file using an editor. Once that works, we can build on it.
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