Getting numbers from a text file with C

**Help_with_C** · 10-19-2010

This is a program that I have to make please somebody help me

The purpose of the task is to implement a program that reads the contents of a text
file (in.txt) and if it qualifies for an arithmetic expression set out below,
perform the specified arithmetic operation and record the results in a binary file (out.dat).
Arithmetic expression must meet the following conditions:
• is enrolled in a row;
• consists of two integer operands separated by the sign of arithmetic operation;
• arithmetic operations are permitted: "+" and "-";
• there is allowed an unlimited number of whitespace (space - '' and
char - '\ t') before and after the sign for simple operation;
• there is allowed an unlimited number of whitespace at the beginning and end of
arithmetic expression.
Example:
in.txt: "158 + 7"
out.txt: Contains binary written the number 165

Thanks

The code I have written for now is:

Code:

 #include<stdio.h>

int main()
{
FILE *fp;
int c;
char h;

fp = fopen("sample.txt", "r");
if(fp == NULL) {
printf("Input file not found!");
return 1;
}

while (EOF != (c = fgetc(fp)))
printf("%c", c);

return 0;
}

**bithub** · 10-19-2010

Here's some ideas to get you going. This is not complete code (and I left out the EOF error checking that will be needed in your final application).

Code:

int operand1 = 0, operand2 = 0;

while (EOF != (c = fgetc(fp)))
{
    if(isdigit(c))
    {
        /* This is a digit, and therefore is part of operand1 */
    }
}

c = fgetc(fp);
if(c == '+')
{
    /* This is an addition operation */
}
else if(c == '-')
{
    /* This is subtraction */
}
else
{ 
    /* Error, we expected + or - */
}

while (EOF != (c = fgetc(fp)))
{
    if(isdigit(c))
    {
        /* This is a digit, and therefore is part of operand2 */
    }
}

There are better ways of solving your problem than the code up above, but I wanted to keep it simple.

**Swarvy** · 10-19-2010

An alternative to going through the file character by character and filtering out the useless information from the actual mathematical expression is to use strtok(). I leave it to you to decide which method you prefer.

Thread: Getting numbers from a text file with C

Thread Tools

Search Thread

Display

Getting numbers from a text file with C

Similar Threads

Newbie homework help

Can we have vector of vector?

gcc link external library

How to use FTP?

Unknown Memory Leak in Init() Function