473,320 Members | 2,202 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,320 software developers and data experts.

Help: ifstream not getting passed to a function

I just found that my fin stream is not getting passed to my
readInASpinnerbait function. Here's what I have:

string readInFirstChars(ifstream &fin)
{
char first[2];
string print;
while (fin.good())
{
fin.get(first, 4, '/');
if (strcmp(first, "sp")==0) {
cout << first << endl; // debugging: outputs 'sp'
string print = "spinnerbait";
readInASpinnerbait(fin); // fin not getting passed
fin.ignore(80, '\n');
return print;
}
}
return 0; }

void readInASpinnerbait(ifstream &fin)
{
cout << "it should read 'sp' right after this" << endl; //it doesn't
char first[2];
string print;
fin.get(first, 4, '/');
cout << first << endl;
// debugging: it doesn't output 'sp'...so fin is not getting
passed.
Spinnerbait spinnerbaitLure;
SpinnerbaitList spinList;
spinnerbaitLure.inputSpinnerbait(fin);
while (!fin.fail()) {
spinList.insertSpinnerbait(spinnerbaitLure, 0);
spinnerbaitLure.inputSpinnerbait(fin);
}
}

I don't understand why fin wouldn't be getting passed here. This seems
simple enough. On a whim, I even tried changing that to istream &sin.
No go. I'd appreciate ANY input. Thanks!

Frank

Jul 22 '05 #1
5 1868
Francis Bell <ph**********@charter.net> wrote in news:10b1l5rcmnijvd6
@corp.supernews.com:
I just found that my fin stream is not getting passed to my
readInASpinnerbait function. Here's what I have:


What do you mean by "not getting passed"? Do you mean, that the argument
'sinks' between the function call?

The problem lies in the code you haven't posted, I suppose.

Cheers.
Jul 22 '05 #2

"Francis Bell" <ph**********@charter.net> wrote in message
news:10*************@corp.supernews.com...
I just found that my fin stream is not getting passed to my
readInASpinnerbait function. Here's what I have:

string readInFirstChars(ifstream &fin)
{
char first[2];
char first[4];
string print;
while (fin.good())
{
fin.get(first, 4, '/');
You are reading upto four characters in here, so you must declare first as
having four characters.
if (strcmp(first, "sp")==0) {
cout << first << endl; // debugging: outputs 'sp'
string print = "spinnerbait";
readInASpinnerbait(fin); // fin not getting passed
fin.ignore(80, '\n');
return print;
}
}
return 0; }

void readInASpinnerbait(ifstream &fin)
{
cout << "it should read 'sp' right after this" << endl; //it doesn't
char first[2];
Ditto, char first[4];
string print;
fin.get(first, 4, '/');
cout << first << endl;
// debugging: it doesn't output 'sp'...so fin is not getting
passed.
Spinnerbait spinnerbaitLure;
SpinnerbaitList spinList;
spinnerbaitLure.inputSpinnerbait(fin);
while (!fin.fail()) {
spinList.insertSpinnerbait(spinnerbaitLure, 0);
spinnerbaitLure.inputSpinnerbait(fin);
}
}

I don't understand why fin wouldn't be getting passed here. This seems
simple enough. On a whim, I even tried changing that to istream &sin.
No go. I'd appreciate ANY input. Thanks!


It should be istream&, but that not the problem.

I see you are using a string (the variable print), why don't you use a
string instead of an array for first? Te big advantage of strings is that
they automatically grow, you don't have to say how big they are, so you
can't make the mistake you've made with first. The other advantage is that
you can compare strings with ==, you don't have to use strcmp.

string first;
getline(first, '/');
if (first == "sp")

Very simple.

john
Jul 22 '05 #3
>
string first;
getline(first, '/');
getline(fin, first, '/');
if (first == "sp")


Sorry.

john
Jul 22 '05 #4
Francis Bell wrote:
I just found that my fin stream is not getting passed to my
readInASpinnerbait function. Here's what I have:
This is impossible (or so I would like to think...).
What do you mean by "doesn't get passed"?
string print;
fin.get(first, 4, '/');
cout << first << endl; // debugging: it doesn't output
// 'sp'...so fin is not getting passed.


I am suspicious about your logic. You read "sp" before sending fin to
the function. Then you expect to read it again?????

After read, the internal pointer is moved forward. Hence consecutive
calls to ifstream::read will not give you the same result, unless you
have a repeated string....

What I mean, unless your input is "spsp", and you call read with 2
instead of 4 as your argument, you shouldn't get back "sp" on
consecutive reads.

JLR
Jul 22 '05 #5
Jorge Rivera wrote:
Francis Bell wrote:
I just found that my fin stream is not getting passed to my
readInASpinnerbait function. Here's what I have:

This is impossible (or so I would like to think...).
What do you mean by "doesn't get passed"?
> string print;
> fin.get(first, 4, '/');
> cout << first << endl; // debugging: it doesn't output
> // 'sp'...so fin is not getting passed.


I am suspicious about your logic. You read "sp" before sending fin to
the function. Then you expect to read it again?????

After read, the internal pointer is moved forward. Hence consecutive
calls to ifstream::read will not give you the same result, unless you
have a repeated string....

What I mean, unless your input is "spsp", and you call read with 2
instead of 4 as your argument, you shouldn't get back "sp" on
consecutive reads.

JLR

Thanks everyone for your input. I was doing it completely wrong. I was
treating like something like an integer or the like that can be passed
by value or reference. I've still got a problem with 'data flow'
somewhere that I haven't been able to trace, but I'm going to look at it
a little more before trying to post that here; it involves several
functions. Thanks all for your help!

Frank

Jul 22 '05 #6

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

3
by: Mahmood Ahmad | last post by:
Hello, I have written a program that reads three types of records, validates them acording to certain requirements and writes the valid records into a binary file. The invalid records are...
7
by: ragi | last post by:
Short version of my program: ifstream File; File.open("test.txt"); if(!File.good()) return; Func(File); <--cannot convert parametr 1 from 'std::ifstream' to 'std::istream'
3
by: Drewdog | last post by:
I am getting some error messages which I can't figure out their meaning. I have the code setup, I think it's correct but it doesn't work. My goal is to get this program to read from a data file and...
5
by: SStory | last post by:
Hi all, I really needed to get the icons associated with each file that I want to show in a listview. I used the follow modified code sniplets found on the internet. I have left in...
8
by: acheron05 | last post by:
Hi there, Hopefully I won't fit the stereotype of the typical student posting his assignment to be written for him, but I am quite stuck. If anyone could give me some help in how to create...
10
by: B. Williams | last post by:
I have an assignment that requires me to write a program that uses a class, a constructor, a switch, and store the records in a text file. The second requirement is to create a function called...
3
NewYorker
by: NewYorker | last post by:
Hello brothers and sisters, Please help me complete this program and get the output shown below. Here is all I have ___________________________________________________________ This...
6
by: priyajohal | last post by:
#include<fstream.h> #include<process.h> #include<stdlib.h> #include<conio.h> #include<string.h> #include<dos.h> #include<ctype.h> #include<stdio.h> void setup() void help();
4
by: charmeda103 | last post by:
i have this program that i am almost done with, i am one part away from being done. the last part is putting the results together; here is the results that i need to put in code. do u have any...
0
by: DolphinDB | last post by:
The formulas of 101 quantitative trading alphas used by WorldQuant were presented in the paper 101 Formulaic Alphas. However, some formulas are complex, leading to challenges in calculation. Take...
0
by: DolphinDB | last post by:
Tired of spending countless mintues downsampling your data? Look no further! In this article, you’ll learn how to efficiently downsample 6.48 billion high-frequency records to 61 million...
0
by: ryjfgjl | last post by:
ExcelToDatabase: batch import excel into database automatically...
0
by: jfyes | last post by:
As a hardware engineer, after seeing that CEIWEI recently released a new tool for Modbus RTU Over TCP/UDP filtering and monitoring, I actively went to its official website to take a look. It turned...
0
by: ArrayDB | last post by:
The error message I've encountered is; ERROR:root:Error generating model response: exception: access violation writing 0x0000000000005140, which seems to be indicative of an access violation...
1
by: PapaRatzi | last post by:
Hello, I am teaching myself MS Access forms design and Visual Basic. I've created a table to capture a list of Top 30 singles and forms to capture new entries. The final step is a form (unbound)...
0
by: CloudSolutions | last post by:
Introduction: For many beginners and individual users, requiring a credit card and email registration may pose a barrier when starting to use cloud servers. However, some cloud server providers now...
0
by: Defcon1945 | last post by:
I'm trying to learn Python using Pycharm but import shutil doesn't work
0
by: Faith0G | last post by:
I am starting a new it consulting business and it's been a while since I setup a new website. Is wordpress still the best web based software for hosting a 5 page website? The webpages will be...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.