ASCII-2-Binary Algorithm

Recall from class, the following algorithm was provided to convert a string of binary digits into a decimal number.

1. set v = 0

2. For each digit (from left to right)

   1. v = v * base;

   2. v = v + digit;

3. print v

Let's create a new algorithm in which

• the string of digits are not numbers but ASCII characters,

• the read system call is used to perform the input operation, and

• java-like syntax is use

The revised algorthm is as follows:

1. offset = 0x30;

2. number = 0;

3. retval = read(0, &ascii_value, 1);

4. while (retval == 1)

   1. digit = ascii_value - offset;

   2. number = ( number << 1 ) + digit; // same thing as: number = number * 2 + digit;

   3. retval = read(0, &ascii_value, 1);

5. printf("%u ", number); # the %u indicates that 'number' is an unsigned quanity

6. return 0;

Your task is to write a C program that

• reads a string of ASCII values from stdin (notice on line 3 of the algorithm provided, you are reading these values one character at a time.)

• converts the ASCII values into a unsigned decimal number

• prints the final decimal number to stdout

You need to augment the algorthm in the following ways.

• allow the string to be terminated by either

  • the end of file, or

  • the newline (nl) character: as depicted as LF and ' '

• validate that each ASCII value is within the range: 48-49

• an error in input should result in the program returning the value of 1