Using putchar to output an integer with more than 1 digit
Hi, I'm trying to create a program that does simple C arithmetic calculations (such as 12 + 12). There can be multiple blanks before and after an operand. The expression and result and expression is supposed to be displayed like 12+12=24, where the expression (12+12) must be output from only using putchar. The = and result (24) can be used with a printf function, but anything dealing with the expression can not be used with printf (putchar only.) So far, I just want to know how I can store the operand (12 for example) and output it.
Code:
#include <stdio.h>
int convert(void);
int main(void)
{
int op1;
op1 = convert();
printf("%d", op1);
return 0;
}
int convert(void)
{
int iochar,
sum = 0;
while(((iochar = getchar() ) != ' ' ) && (iochar != '\n' ) )
{
sum = sum * 10 + (iochar - '0');
}
return (sum);
}
The code I have above was used mostly from a convert function from my programming book which reads from standard input until either a blank or end of line is found. It works, but only because printf function is being used in main. If I enter something such as putchar(op1); instead of printf("%d", op1);, I get some awkward results (symbols, alt codes, etc.) Any advice would be highly appreciated, I just want to know how I can store the integer (with more than 1 digit) using getchar and also output it using putchar. I've also tried tackling the problem with a different piece of code, but only the first number of the operand would be output (instead of 12, it would only output 1.)
