I've been doing quite well in my class, but I've finally hit something that I can't figure out.

Basically, we have to decode a text file back to english (Caesar Cipher), and we have to run the text file through the our progame via the Command Prompt.

I've finished writing my code, but I can't get it to feed me back any output -- wrong or right.

I don't get an error or anything just this:

(checking to see if files I need are there, they are)
+ Show Spoiler +

(running the txt file through my program, maybe?)
+ Show Spoiler +

As you can see, nothing happens, and no errors appear either.

thats how I was instructed to do it and it's worked once before the other day, but now I finished writing my code and I can't test it =/

If you feel like taking the time, you can look at that as well:

+ Show Spoiler +

#include <iostream>
#include <iomanip>
#include <math.h>

using namespace std;

char reverseCaesar( char ch );
char convPunct( char ch );
char convDigit( char ch );
char convRest(char ch);
//***************************************************************************************************************************
int main()
{
char ch;
int change;

cin >> ch;

while ( cin )
{
char change;
if( isalpha(ch) )
{
change = reverseCaesar(ch);

}
else if (ispunct(ch) )
{
change = convPunct(ch);

}
else if (isdigit(ch) )
{
change = convDigit(ch);

}

else
change = convRest(ch);

cin >> ch;
}

system ("pause");
return 0;
}

//***************************************************************************************************************************

char reverseCaesar( char ch )
{
int i;

if (ch <= 47 && ch > 44)
{
i = (int)ch + 23;
}
else if (ch <=99 && ch > 96)
{
i = (int)ch +23;
}
else

i = (int)ch - 3;

return char(i);
}

char convPunct( char ch )
{
switch(ch)
{
case ',': return '0';
break;
case '.': return '1';
break;
case '$': return '2';
break;
case '&': return '3';
break;
case '%': return '4';
break;
case '*': return '5';
break;
case '(': return '6';
break;
case ')': return '7';
break;
case '?': return '8';
break;
case '!': return '9';

default: return ch;

}
}

char convDigit( char ch )
{
switch(ch)
{
case '0': return '!';
break;
case '1': return ',';
break;
case '2': return ')';
break;
case '3': return '(';
break;
case '4': return '?';
break;
case '5': return '-';
break;
case '6': return '&';
break;
case '7': return '$';
break;
case '8': return '.';
break;
case '9': return '+';
break;

default: return ch;

}
}

char convRest(char ch)
{
if(ch==21)
ch='\n';
else if(ch==22)
ch=' ';
else
ch=ch;

return ch;
}

I haven't added documentation, but it's fairly straight forward -- taking the characters from the txt file and decoding them (we had to write and use our own functions as well).

I'm willing to bet my program wouldn't work even if I could see it, but i'd at least like to try.

any help would appreciated, it's due in a couple of hours =)

if I have to i'll just submit and see if I can edit and resubmit tomorrow .

thanks.

Shade692003

Canada702 Posts

October 17 2009 02:58 GMT

been pretty long since I've done anything like coding or w/e, but if I understand correctly you enter your text file path as a parameter for your program? shouldn't there be parameters in your main then?

DrTJEckleburg

United States1080 Posts

October 17 2009 02:58 GMT

I have no help for your question, but I do believe that your reign at the top of LB will end after you bet on MBC over KT Rolster.

paper

13196 Posts

October 17 2009 02:59 GMT

voting for MBC is your problem

edit: YOU GUYS ARE TOO FAST

keV.

United States3214 Posts

October 17 2009 03:00 GMT

Wait a minute something isn't right here.

I'm pretty sure you can't read a txt file with cin, while expecting a char.

I don't know the details of your assignment, but do you take the file you are reading from as a parameter? If you do, then you definitely need to take some command line arguments. If not, then you can just open the file in your main or accept it by input string, and read char by char until the end of file.

AcrossFiveJulys

United States3612 Posts

October 17 2009 03:01 GMT

I'm a little confused about what you're asking, but I think you are asking why your program doesn't "do" anything when you run it. Okay, so given that...

Your second screenshot shows you running the program with the file as input correctly.

Now, your program doesn't produce any output on the command prompt because you aren't telling it to print anything. Use cout if you want to print messages to the command prompt. If you are trying to create a new file that contains the translation of the original file, you'll need to use an ofstream and output to that, or use "> some_file" when running the program and print to some_file using cout.

eMbrace

United States1300 Posts

October 17 2009 03:01 GMT

On October 17 2009 11:58 DrTJEckleburg wrote:
I have no help for your question, but I do believe that your reign at the top of LB will end after you bet on MBC over KT Rolster.

i'm on top for a reason

AcrossFiveJulys

United States3612 Posts

October 17 2009 03:03 GMT

On October 17 2009 12:00 keV. wrote:
Wait a minute something isn't right here.

I'm pretty sure you can't read a txt file with cin, while expecting a char.

Yes you can. Since he's using the "<" operator when running the program, it changes the stdin stream (which is what cin uses) to refer to the file instead of user input.

Shade692003

Canada702 Posts

October 17 2009 03:03 GMT

On October 17 2009 12:00 keV. wrote:
Wait a minute something isn't right here.

I'm pretty sure you can't read a txt file with cin, while expecting a char.

I think the cin are for reading the characters in the text files, once they are read he changes them according to their values. could be wrong tho.

Anyhow there is no output like the other guy said

eMbrace

United States1300 Posts

October 17 2009 03:05 GMT

#10

On October 17 2009 12:01 AcrossFiveJulys wrote:
I'm a little confused about what you're asking, but I think you are asking why your program doesn't "do" anything when you run it. Okay, so given that...

Your second screenshot shows you running the program with the file as input correctly.

Now, your program doesn't produce any output on the command prompt because you aren't telling it to print anything. Use cout if you want to print messages to the command prompt. If you are trying to create a new file that contains the translation of the original file, you'll need to use an ofstream and output to that.

to put it into a new file, they taught us this format

program < input.txt > new.txt

i get a new file with nothing in it =/

Shade692003

Canada702 Posts

October 17 2009 03:05 GMT

#11

So hmm, shoudn't you cout that ''change'' variable?

Edit: Try to cout the change variable at the end of the while loop, might cout the value into the new text file.

keV.

United States3214 Posts

October 17 2009 03:05 GMT

#12

On October 17 2009 12:03 AcrossFiveJulys wrote:

Show nested quote +

Yes you can. Since he's using the "<" operator when running the program, it changes the stdin stream (which is what cin uses) to refer to the file instead of user input.

I don't think reading from a file without a file handle is a good idea.

its sad how long its been since I've worked with simple I/O input...

vAltyR

United States581 Posts

October 17 2009 03:05 GMT

#13

Commenting is your best friend. Especially when you're asking others to help with your program. I didn't think it'd make that much difference, but I've had time where I look back on code and think "wtf was I doing here again?"

Do you need to separate it into functions like that? Sometimes it gets confusing debugging so many functions, especially when the code isn't your own.

EDIT: Wait a second... You're reading this from a file, right? You have nothing set up for file IO.

Ironson

20 Posts

October 17 2009 03:06 GMT

#14

The program is well formed, but it doesn't output anything! You need to write the output to "cout" and stream it into a file. Your command would become something like: pgm6 < input.txt > output.txt

keV.

United States3214 Posts

October 17 2009 03:07 GMT

#15

Like whats been said in this thread, you need to either rewrite the original file as you read char by char or you need to print the output to a a new file or screen.

eMbrace

United States1300 Posts

October 17 2009 03:08 GMT

#16

On October 17 2009 12:06 Ironson wrote:
The program is well formed, but it doesn't output anything! You need to write the output to "cout" and stream it into a file. Your command would become something like: pgm6 < input.txt > output.txt

ok right, but how exactly do I make my program cout all the decoded characters at once after the loop is over?

and sorry for the code with out comments -- we did have to write functions to use in the main, i guess it's a way of them making us learn how they work.

Ironson

20 Posts

October 17 2009 03:09 GMT

#17

Before your second "cin >> ch;", place "cout << change;".

eMbrace

United States1300 Posts

October 17 2009 03:13 GMT

#18

On October 17 2009 12:09 Ironson wrote:
Before your second "cin >> ch;", place "cout << change;".

woah, it worked.

got all the decoded next in a new file.

thanks a lot everyone -- you may have saved my A in this class.

now I can watch MBC just roll over KT tonight

keV.

United States3214 Posts

October 17 2009 03:13 GMT

#19

this should give you simple error checking output.

+ Show Spoiler +

int main()
{
char ch;
int change;

cin >> ch;

while ( cin )
{
char change;
if( isalpha(ch) )
{
change = reverseCaesar(ch);

}
else if (ispunct(ch) )
{
change = convPunct(ch);

}
else if (isdigit(ch) )
{
change = convDigit(ch);

}

else
change = convRest(ch);
//output goes here

cin >> ch;
}

system ("pause");
return 0;
}