Hi everyone. I am an undergraduate student of mechanical engineer and i am trying to make a program that will convert a decimal number to a binary one and a hexadecimal one using c . The problem is that i am not familiar with c at all. I am only familiar with Basic and python. Anyway, doing some research in here i have managed to find this code

```
#include <stdio.h>
int main(void)
{
int hexa = 16, deci, quotient, ctr;
printf("enter decimal number: ");
scanf("%d",&deci);
for (ctr = 1; ctr<=deci; ctr++)
quotient = deci / hexa;
printf("Equivalent in Hexadecimal is %d",quotient);
printf("\n\n Try this for Hexadecimal: %X\n", deci);
getchar();
return 0;
}
```

for decimal to hexadecimal conversion and this

```
#include <stdio.h>
void dec2bin(long decimal, char *binary);
int main()
{
long decimal;
char binary[80];
printf("\n\n Enter an integer value : ");
scanf("%ld",&decimal);
dec2bin(decimal,binary);
printf("\n The binary value of %ld is %s \n",decimal,binary);
getchar(); // trap enter
getchar(); // wait
return 0;
}
//
// accepts a decimal integer and returns a binary coded string
//
void dec2bin(long decimal, char *binary)
{
int k = 0, n = 0;
int neg_flag = 0;
int remain;
int old_decimal; // for test
char temp[80];
// take care of negative input
if (decimal < 0)
{
decimal = -decimal;
neg_flag = 1;
}
do
{
old_decimal = decimal; // for test
remain = decimal % 2;
// whittle down the decimal number
decimal = decimal / 2;
// this is a test to show the action
printf("%d/2 = %d remainder = %d\n", old_decimal, decimal, remain);
// converts digit 0 or 1 to character '0' or '1'
temp[k++] = remain + '0';
} while (decimal > 0);
if (neg_flag)
temp[k++] = '-'; // add - sign
else
temp[k++] = ' '; // space
// reverse the spelling
while (k >= 0)
binary[n++] = temp[--k];
binary[n-1] = 0; // end with NULL
}
```

for decimal to binary conversion.

Now my problem is that i want to enhance this by adding two features

a)I want the user to be able to give the integer for conversion straight from the command line. I think that this is possible by using the argc and argv but i am not sure on how to do so.

b)Secondly i want the user to be able to to write the results in a txt file using again some kind of command from the terminal.

Any help or guidance would be much appreciated

thanks in advance