6.6 Returning multiple values

6.6 Returning multiple values

In this lab I want you to go quite a bit further than you did in lab 6.3: Numbers/Character Processing. I want you to write a program that returns (as its return value) the next number received as characters into its standard input.

The signed numbers can be in several formats:

Binary	0b1010101	Must start with a 0b and only 0 & 1
Octal	01234567	Must start with a zero and only 0-7
Decimal	123456789	Must start with 1-9
Hexadecimal	0xhhhhhhh	h is one of 0-9 & A-F (Uppercase)

If there is a "-" directly prior to the number it is a negative number.

0bA and 0xG can be considered a zero binary and zero hexadecimal number respectively.

Numbers are terminated my any character that is not part of their set of characters. For example, an octal number is terminated by a 8 or a 9 and a binary number would be terminated by a 2. This terminating character should be "put back" with a call to ungetchar() so it can be used in the next number. For example, 0123456789 will first return a octal number of 1234567₈ and then a decimal value of 89₁₀.

A hexadecimal number can be terminated by any lower case letter.

Spaces, new lines, tabs, G-Z, and a-z terminate all numbers. Any special character or non-printing character also terminate all numbers.

The function prototype should look something like this:

int getnumber(int *error, int *radix, int *characters_read);

error should return the following values:

0	Found a valid number
-1	Numeric overflow
-2	End of file

If an overflow occurs, the return value needs to be set to zero.

radix should return the following values:

0	No number found
2	Binary number
8	Octal number
10	Decimal number
16	Hexadecimal number

characters_read need to have the total number of character read from the input minus any put back.

At the start of your program print out:

• Your name
• CIS265 Louis Taber
• Lab: 6.6: Multiple return values

Write a program that process an input data doing the following:

• Process the input, looking for numbers, until the end-of-file condition occurs.
• For each number it finds it need to print out the number the radix, and if an overflow occurred.
• At the end of the program print out the sum of:
  1. All numbers.
  2. All numbers of a given radix.
  3. The number of characters processed.
  4. The number of times an overflow occurred.

Given the following example input.

abcde 0b0101 -012 123 0x05A -123

Your name
CIS265  Louis Taber
Lab: 6.6: Multiple return values

Binary                      5
Octal                     -10
Decimal                   123
Hexadecimal                90
Decimal                  -123

EOF reached  ****************
Binary total                5
Octal total               -10
Decimal total               0
Hexadecimal total          90
Grand total                85
Number of overflows         0
Total characters read      35

This is the test data for the multiple returns lab.
If you have sixteen bit integers, create your own file.

0b11111 037 31 0x1F  Four thirty ones
-0b11111 -037 -31 -0x1F  Four negative thirty ones
0b11111111111111111111111111111111  Binary overflow
077777777777 Octal overflow
2147483648 Decimal overflow
0x80000000 Hexadecimal overflow
2147483647 Decimal max
-2147483648 Decimal min  (sum now minus one)

Run together numbers.
0b12 (Binary one, decimal two)
078  (Octal seven, decimal eight)
0xA0b10 (Hexadecimal One Hundred sixty, decimal ten)
This is the last line

It is available by anonymous ftp at
ftp://lt.tucson.az.us/pub/c/return.dat.

Turn in a copy of your program and its output when used with the above test data marked with:

• Your name
• TABER CIS265
• Lab 6.6: Returning multiple values
• The compiler and OS that you used.

6.6 Returning multiple values