opening a file... should be easy fix

will someone please tell me why this won't open the file "defs.dat", i have the "defs.dat" in the same folder as the .cpp program, i don't understand...

Code:

---

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream.h>
#include <fstream.h>
#include <ctype.h>


// class definition
class wordanddef
{
public:
        char word[20];
        char def[80];
};

// function definitions
int loaddata(char *fn, wordanddef *wadptr[]);
void sortdata(int numlines, wordanddef *wadptr[]);
int findword(int numlines, wordanddef *wadptr[], char *wrd);

// main program
int main(void)
{
char fname[100], sword[20], origword[20];
int linecnt, fwordnum, ccnt;
wordanddef *pwordanddef[400];

        // setup file name
        strcpy(fname, "defs.dat");

        // load data from file, returns number of line read from file
        linecnt=loaddata(fname, pwordanddef);
        if(linecnt==-1)
        {
                cout<<"File open failed.\n";
        system("Pause");
                exit(1);
        }

        // sort the data
        sortdata(linecnt, pwordanddef);

        // allow user to search for words
        while(1)
        {
                // prompt user for search word
                cout<<"\nEnter the word to search for, or leave blank to quit:  ";
                cin.getline(sword, 20);
        strcpy(origword, sword);

                // change all characters to upper case
                for(ccnt=0; ccnt<strlen(sword); ccnt++)
                sword[ccnt]= toupper(sword[ccnt]);

                // exit for blank search word
                if(strcmp(sword, "")==0) exit(1);

                // search for the word
                fwordnum=findword(linecnt, pwordanddef, sword);

                // print the result
                if(fwordnum==-1) cout<<"\nNot found.\n";
                else
                {
                        cout<<"\nWord found.\n";
            cout<<"Original word as typed (LaRue): "<<origword<<"\n";
                        cout<<"Word: "<<pwordanddef[fwordnum]->word<<"\n";
                        cout<<"Definition: "<<pwordanddef[fwordnum]->def<<"\n";

                }
        }

}

// function to load data from file
int loaddata(char *fn, wordanddef *wadptr[])
{
ifstream file;
char line[80];
int i, j;
int cnt=0;

        // open the file
        file.open(fn);

        // make sure file opened okay
        if(file.fail()) return -1;

        // read until end of file
        while(!file.eof())
        {
                // set character counters
                i=0;
        j=0;

                // get line into character string
                file.getline(line, 80, '\n');

                // new class instance
                wadptr[cnt] = new wordanddef;

                // copy the word into the new class, change all characters to upper case
                while(i<strlen(line))
                {
                        if(line[i]!=' ') wadptr[cnt]->word[i]=toupper(line[i]);
            else break;
                        i++;
                }
                wadptr[cnt]->word[i]=0;

                // skip the white space between word and definition
                while(line[i]==' ')
                i++;
               
                // copy the definition into the new class
                while(i<strlen(line))
                {
                        if(line[i]!=' ') wadptr[cnt]->def[j]=line[i];else break;
                        i++;
                        j++;
                }
                wadptr[cnt]->def[j]=0;

                // increase the line count
                cnt++;
        }

        // close the file
        file.close();

        // return the number of lines
        return cnt;
}

// function to sort data by alphabet
void sortdata(int numlines, wordanddef *wadptr[])
{
int swap, sortcnt;
wordanddef *twadptr;

        // sort the pointers, alpha by word
        swap=1;
        while(swap)
        {
                swap=sortcnt=0;
                while(sortcnt<numlines-1)
                {
                        if(strcmp(wadptr[sortcnt]->word, wadptr[sortcnt+1]->word)>0)
                        {
                                twadptr=wadptr[sortcnt];
                                wadptr[sortcnt]=wadptr[sortcnt+1];
                                wadptr[sortcnt+1]=twadptr;
                                swap=1;
                        }
                        sortcnt++;
                }
        }
}

// search data for a word
int findword(int numlines, wordanddef *wadptr[], char *wrd)
{
int i;

        for(i=0; i<numlines; i++)
        {
                if(strcmp(wadptr[i]->word, wrd)==0) return i;
        }

        return -1;
}

---

What compiler are you using? How are you running the program, from within an IDE of some kind or from the command line?

Code:

---

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream.h>
#include <fstream.h>
#include <ctype.h>

---

These are all old/deprecated headers, you should be using the newer ones if possible:

Code:

---

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <fstream>
#include <cctype>
using namespace std;

---

You can potentially overrun your pwordanddef array in your code. You allocate space for a maximum of 400 elements but do nothing in your loaddata function to guard against more than 400 records being loaded:

Code:

---

int cnt=0;

// open the file
file.open(fn);

// make sure file opened okay
if(file.fail()) return -1;

// read until end of file
while(!file.eof())
{
    ...

    // new class instance
    wadptr[cnt] = new wordanddef;

    ...

    // increase the line count
    cnt++;
}

---

You can easily protect yourself against over running this array:

Code:

---

int cnt=0;

// open the file
file.open(fn);

// make sure file opened okay
if(file.fail()) return -1;

// read until end of file
while(!file.eof() && cnt < 400)
{
    ...

    // new class instance
    wadptr[cnt] = new wordanddef;

    ...

    // increase the line count
    cnt++;
}

---

You have similar potential problems copying the word and definition into the class members. word can hold at most 20 characters with the last character always being set to 0, thus you should make sure you only copy at most 19 characters into the array. Likewise for the def member you should only copy at most 79 characters into the array, the last one always being set to 0:

Code:

---

// copy the word into the new class, change all characters to upper case
while(i<strlen(line) && i < 19 )
{
    if(line[i ]!=' ') wadptr[cnt]->word[i ]=toupper(line[i ]);
    else break;
    i++;
}
wadptr[cnt]->word[i ]=0;

...

// copy the definition into the new class
while(i<strlen(line) && j < 79)
{
    if(line[i ]!=' ') wadptr[cnt]->def[j]=line[i ];
    else break;
    i++;
    j++;
}
wadptr[cnt]->def[j]=0;

---

As an aside, your program seems a perfect opportunity for use of a map<string,string> STL container. You wouldn't need to allocate space for an array of objects. The sorting is handled automatically for you by the container itself. Adding and searching for elements in the container is easy.

At the very least you could look up how to use the string containers. They could help tremendously here.

thanks alot, i got it workin.... i know about protecting for the buffer overrun, but there will never be more than 19 entered for the word to search for and no more than 79 ever for the definition, otherwise i would've put that in there, heck, i might as well do it anyways just to protect against it, i'm not familiar with the string containers, are they covered in the FAQ?

Quote:

---

Originally Posted by hk_mp5kpdw

Code:

---

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream.h>
#include <fstream.h>
#include <ctype.h>

---

These are all old/deprecated headers, you should be using the newer ones if possible:

---

Not old nor deprecated... Simply don't comply with the C++ standard. Those are C standard libs...!

Actually,

Code:

---

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

---

I believe these are standard in C++, but they are deprecated in favor of the C++ versions.

Code:

---

#include <iostream.h>
#include <fstream.h>

---

and these are non-standard in C and C++, and are therefore just old.

So hk_mp5kpdw was correct, those headers are all old and/or deprecated.

A possible version of this program using strings and a map:

Code:

---

#include <map>
#include <iostream>
#include <iterator>
#include <algorithm>
#include <string>
#include <fstream>
#include <cctype>
using namespace std;


// function definitions
bool loaddata(string fn,map<string,string>& dict);


const string fname = "defs.dat";


int main()
{
    map<string,string> dictionary;        // Store our word/definition pairs

    // load data from file
    if( !loaddata(fname,dictionary) )
    {
        cout << "File open failed.\n";
        cin.get();
        exit(1);
    }

    //exit if nothing loaded into dictionary
    if( dictionary.empty() )
    {
        cout << "No entries loaded into dictionary.\n";
        cin.get();
        exit(1);
    }
    else cout << dictionary.size() << " entries have been loaded into dictionary.\n";

    // allow user to search for words
    while(1)
    {
        string word, original;

        // prompt user for search word
        cout<<"\nEnter the word to search for, or leave blank to quit:  ";
        getline(cin,original);
        cin.ignore(80,'\n');
                       
        // exit for blank search word
        if( !original.length() ) break;

        // change all characters to upper case
        transform(original.begin(),original.end(), inserter(word,word.end()), toupper);

        // search for the word
        if( dictionary.find(word) == dictionary.end() )
            cout << "\nCould not find " << word << ".\n";
        else
        {
            cout << "\nWord found.\n";
            cout << "Original word as typed (LaRue): " << original << "\n";
            cout << "Word: " << word << "\n";
            cout << "Definition: " << dictionary[word] << "\n";
        }

    }

    return 0;
}

// function to load data from file
bool loaddata(string fn,map<string,string>& dict)
{
    ifstream file;
    string word, def;
       
    // open the file
    file.open(fn.c_str());

    // make sure file opened okay
    if( !file.is_open() ) return false;

    // read until end of file
    while( !file.eof() )
    {
        file >> word;
        getline(file,def);

        // change all characters in 'word' to upper case
        transform(word.begin(),word.end(),word.begin(), toupper);

        // copy word/definition into the dictionary
        dict[word] = def;
    }

    // return success
    return true;
}

---

Quote:

---

Originally Posted by jlou

Actually,

Code:

---

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

---

I believe these are standard in C++, but they are deprecated in favor of the C++ versions.

Code:

---

#include <iostream.h>
#include <fstream.h>

---

and these are non-standard in C and C++, and are therefore just old.

So hk_mp5kpdw was correct, those headers are all old and/or deprecated.

---

Deprecated symbols or names.. because it's the implementation that counts...

It is advisable to use the standard. Many compilers provide those old headers for convenience. <iostream.h> for example, may very well look like this:

Code:

---

#ifndef __WHATEVER__
#include <iostream>
using std::cout;
using std::cin;
... // etc
##endif

---

Not all compilers will necessarily provide them, and not all compilers will continue to have them indefinitely. There is no reason not to use the standard.