Well, interestingly enough

--\n-------------------------------------------------------------------\n* Jack Troughton jake at consultron.ca *\n* [link|http://consultron.ca|http://consultron.ca] [link|irc://irc.ecomstation.ca|irc://irc.ecomstation.ca] *\n* Kingston Ontario Canada [link|news://news.consultron.ca|news://news.consultron.ca] *\n-------------------------------------------------------------------

\n/* Source file for the C program in Assignment 1 of CISC221 - Computer\n * Architecture, for Dr. Clive Dove. */\n\n/* Header Declarations */\n\n#include <stdio.h>\n\n#define SIZE 80\n\nint value1, value2, sum;        // variables to hold values entered by user after \n                                // conversion to numbers.\n\nchar instring[SIZE];    // String to hold number entered by user. Size is large \n                        // to ensure that there is no buffer overflow.\n\nchar error[20]; // string to hold error messages.\n\n/* Here there be function declarations. There are two functions; one to\n * convert an ascii string into an int value, and one to handle erroneous\n * input by the user. */\n\nint ascToInt(char []); // Converts ascii strings to ints.\n\nint inputOnError(char []); // Handles input outside specified range.\n\nint main()\n{\n\n        while (1)\n                // this loops until user puts sentinal value into value1 that causes program\n\n                // to exit.\n        {\n                printf("Please enter a number between -128 and 127.\\nEnter zero to exit:");\n                scanf("%s", instring);\n                value1 = ascToInt(instring);\n                if (value1 == 0)\n                        return 0; // Exit the program when user inputs 0 into first value.\n\n                printf("Please enter another number between -128 and 127:");\n                scanf("%s", instring);\n                value2 = ascToInt(instring);\n\n                sum = value1 + value2;\n\n                printf("%x + %x = %x, sum = %d, v = %d\\n", value1 & 0xFF, value2 & 0xFF, sum & 0xFF, sum, (sum < -128 || sum > 127));\n        }\n}\n\n\nint ascToInt(char *s)\n{\n        int result = 0;\n        int sign = 1;\n\n        if (*s == '-') // Test for a sign in the first character of the string.\n\n        {\n                s++;\n                if (!*s) // if next character is null, - is only character.\n                        result = inputOnError("not a number");\n                else\n                        sign *= -1;\n        }\n        while (*s >= '0' && *s <= '9') // while there are digits in the string.\n\n        {\n                result *= 10;\n                result += *s - '0';\n                s++;\n        }\n        result *= sign; // apply the sign\n\n        if (*s) // if there is anything other than a digit in the string.\n                result = inputOnError("not a number");\n\n\n        if (result < -128 || result > 127) // if result is outside of range.\n\n                result = inputOnError("outside the range specified");\n        return result;\n}\n\n/* inputOnError is the error handler for invalid input. It takes one argument\n * of a string indicating the nature of the error, prompts again for input,\n * and then uses the ascToInt function to value it, and returns the result to\n\n * the calling function. */\n\nint inputOnError(char *error)\n{\n        int output;\n        do\n        {\n                printf("The value you entered was %s.\\nPlease re-enter a number between -128 and 127:", error);\n                scanf("%s", instring);\n                output = ascToInt(instring);\n        }\n        while (output < -128 || output > 127);\n\n        return output;\n}

edit: I just wrote it... again:) This time I'm done 'cause after this I'm going to have a beer.

I'd esp. like to thank Todd for giving me the knife and fork and inviting me to dine.

edit2: took out my student number.

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