[KiddKoder]

I am to write a program that reads the standard input file and count the digits, and all other variables, placing the totals in two separate variables.

I do not know exactly what the standard input file is. I told the program to open "stdin".... this is where my problem is I think.

I think the rest of the code should work.

This code compiles but does not run. I get a "Segmentation error." Don't know what that is exactly.

#include <stdio.h>

int main(void)
{
        int digit_cnt = 0, other_cnt = 0, c;
        FILE *f;

        f = fopen("stdin", "r");
        while ((c = fgetc(f)) != EOF)
                if (c >= '0' && c <= '9')
                        ++digit_cnt;
                else if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' ||
                        c == ' ' || c == '\n')
                        ++other_cnt;
        printf("%10s%10s\n", "digits", "other");
        printf("%10d%10d\n", digit_cnt, other_cnt);

        fclose(f);
        return 0;
}

This post has been edited by KiddKoder: 30 October 2010 - 09:41 PM

[janotte]

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[janotte]

Do you think you might have misread the requirements or the teacher might have mistyped them.

Standard input usually means the keyboard.

An input file is a file.

Standrad input file are not really 3 words that go together happily.

Do you think the assignment is actually to read from the keyboard?

[KiddKoder]

janotte, on 30 October 2010 - 08:40 PM, said:

Do you think you might have misread the requirements or the teacher might have mistyped them.

Standard input usually means the keyboard.

An input file is a file.

Standrad input file are not really 3 words that go together happily.

Do you think the assignment is actually to read from the keyboard?

That would make more sense to me, however the exact words in the book are "Write a program that reads characters from the standard input file until EOF is encountered..." I have searched everywhere and cant find an example of this.

This post has been edited by KiddKoder: 30 October 2010 - 09:51 PM

[janotte]

Hmmmm. Interesting. They didn't, earlier in the book say something like, the standard input file for the examples in this book (or chapter or whatever) will be xyz.txt or whatever did they?

Anyway, I am no real help to you in interpreting what they might be trying to say.

Anyone else have a better idea?

EDIT
Arrgh too tired, obviously.
See jimblumberg's clear headed thinking below.
Time for sleep for me it seems!

This post has been edited by janotte: 30 October 2010 - 10:06 PM

[jimblumberg]

When you start a program the operating system opens 3 files by default, stdin, stdout, and stderr. Stdin and stdout are normally the keyboard and monitor, and they are buffered. Stderr is usually the monitor and is not buffered.

Please see the following link stdin and standard streams


Jim

[no2pencil]

Exactly as janotte suggested, EOF is end of file. So either the instructions are wrong, or they meant read until end of line (enter key) is given.

Is it possible that the assignment is to read a file name from standard input? Then read the file until EOF...?

[jimblumberg]

no2pencil, on 30 October 2010 - 10:04 PM, said:

Exactly as janotte suggested, EOF is end of file. So either the instructions are wrong, or they meant read until end of line (enter key) is given.

Is it possible that the assignment is to read a file name from standard input? Then read the file until EOF...?

Actually if you type Control Z (Windows) or Control D (Linux) you will produce eof()

I'm not sure what it is on a Mac.

TRY

#include <iostream>
using namespace std;
int main()
{
   int number;
   cin >> number;  // Type the control and the correct character here.
   if(cin.eof())
     cout << "You entered eof()"
   return 0;
}

Jim

This post has been edited by jimblumberg: 30 October 2010 - 10:28 PM

[no2pencil]

Since Mac OSX is based on FreeBSD I would assume it would be the same on Mac as it is for Linux.

[jimblumberg]

You should not open stdin as it is already open. But the following should work:

while ((c = fgetc(stdin)) != EOF)

Jim

This post has been edited by jimblumberg: 30 October 2010 - 10:37 PM

[KiddKoder]

Thanks everyone for the suggestions.

I ended up just assuming that EOF meant the end of the user's input into stdin, which I set as carriage return.

Here is my final code for anyone curious.

#include <stdio.h>

int main(void)
{
        int digit_cnt = 0, other_cnt = 0, c;

        while ((c = getc(stdin)) != '\n')
                if (c >= '0' && c <= '9')
                        ++digit_cnt;
                else if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' ||
                        c == ' ')
                        ++other_cnt;
        printf("%10s%10s\n", "digits", "other");
        printf("%10d%10d\n", digit_cnt, other_cnt);

        return 0;
}

This post has been edited by KiddKoder: 31 October 2010 - 06:44 AM