How to take input from a file using a C program? - c

Question

I have to take input from a file and convert the number from kelvin to fahrenheit(vice versa), using a "C" program.
Requirements:
The conversion and numeric outputs must take place in the compiled program.
The script will give the user an option to convert either kelvin to fahrenheit or fahrenheit to kelvin.
Numbers need to be rounded to the nearest tenth.
Input file:
0
32
100
212
108
1243
3000
85
22
2388
235
Output File:
Fahrenheit Temperature Kelvin Temperature
0 256
32 273
100 310
212 373
108 315
1243 945
3000 1921
85 302
22 268
2388 1581
235 385
"C" Program:
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
//assign the variables used in this program
int temp, conv_temp, conv_type;
//assign the input options to variables
conv_type = atoi(argv[1]);
temp = atoi(argv[2]);
//convert the temps
// if input number is 1, then convert from kelvin to fahrenheit
// if input number is anything else, convert from fahrenheit to kelvin
if(conv_temp == 1)
conv_temp = (((temp - 273) * 1.8) + 32);
else
conv_temp = ((((temp - 32) *5) / 9) + 273);
//print the data
printf(" %3.1i %3.1i\n",temp, conv_temp);
//end of main function
return 0;
}

Answer 1

You have several issues here.
First: you declare "conv_type" and initialize it, but fail to do anything with it.
conv_type;
conv_type = atoi(argv[1]);
Second: before you give a value for "conv_temp" you are attempting to use it in an if statement.
if(conv_temp == 1)
conv_temp = (((temp - 273) * 1.8) + 32);
else
conv_temp = ((((temp - 32) *5) / 9) + 273);
Third: in the problem statement, you state you have to do file I/O.
Here is a link to a tutorial on file IO in C.