What is wrong with this code, in special with file?

Question

Implement an algorithm that reads a mathematical expression from the standard input and writes to Standard output if the expression is correctly bracketed.

I made the code but I do not know if it's okay how I used the file.

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>

int main()
{
FILE *citire, *scriere; 
char expr[100];
int fe=0,i;


citire = fopen("in.txt", "rb");
scriere = fopen("out.txt", "wb");
fscanf(citire, "%s", &expr);

//input
i = 0;
while (expr[i] != '\0')        
{
    if (expr[i] == '(')
    {
        fe++;
    }
    else if (expr[i] == ')')
    {
        fe--;
        if (fe < 0) 
            break;
    }
    i++;
}
//output
if (fe == 0)
{
    fprintf(scriere, "DA\n");
}
else          
{
    fprintf(scriere, "NU\n");
}
fclose(citire);
fclose(scriere);
return 0;
}

The requirement mentions "standard input" (keyboard) and standard output (screen), so there is no need to use files here. The usage of files looks OK, apart from the missing error checks, — Jabberwocky, May 07 '17 at 13:33
Please read this: [How to ask](https://stackoverflow.com/help/how-to-ask) — Jabberwocky, May 07 '17 at 13:35
"*reads [...] from the standard input and writes to Standard output*" it doesn't. It reads and writes from/to two specific files "directly". — alk, May 07 '17 at 13:35
you have to mention error we r not compiler to parse the code.. :) — siddhesh, May 07 '17 at 13:35
Indeed, in the requirement does not write, but the teacher wants it — Alina Cristina Ciocan, May 07 '17 at 13:37
@AlinaCristinaCiocan then you should mention this in the question. — Jabberwocky, May 08 '17 at 06:48

alk · Answer 1 · 2017-05-07T13:45:19.387

0

To read/write from Standard In-/Output replace this

citire = fopen("in.txt", "rb");
scriere = fopen("out.txt", "wb");

by this

citire = stdin;
scriere = stdout;

and drop the two calls to fclose().

Then call the program like this

./a.out <in.txt >out.txt

Alternatively you could drop the FILE* variables at all and switch from using the general f*() functions to using the Standard-I/O related versions:

fscanf() --> scanf()
fprinf() --> printf()

edited May 07 '17 at 13:45

answered May 07 '17 at 13:38

alk

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Thank you very much – Alina Cristina Ciocan May 07 '17 at 13:42

What is wrong with this code, in special with file?

1 Answers1