Table of Contents

Corning Community College

ENGR1050 C for Engineers

Project: DATA TYPE RANGES (dtr0)

Objective

To familiarize yourself with the available data types in C- the variations, the attributes, the ranges therein.

Prerequisites

In order to successfully accomplish/perform this project, the listed resources/experiences need to be consulted/achieved:

Scope

This project will be exploring the nature of some of the data types available to us in the C Programming Language. How much space is allocated to each type, how many numbers can exist within each type, and what are the ranges available for each type?

A program will be written that will display (to STDOUT) the size (in bytes), the lower and upper bounds of each studied type, and (as accurately as possible) display the total quantity of values possible with each type.

The data types covered for this project will include signed and unsigned variations of:

The sizeof() and printf() functions, as well as arithmetic and logical operators, will be utilized in performing much of the work.

Code

Skeleton Program

Here is the skeleton of a program you'll want to use for this project: 

/*
 * dtr0.c - A program to derive and display information
 *          for the signed and unsigned data types in C
 *
 *
 * A program by NAME for COURSENUMBER COURSENAME (SEMESTER)
 *
 * Compile with: gcc -o dtr0 dtr0.c
 * Execute with: ./dtr0
 */
 
#include <stdio.h>
 
int main()
{
    // Variables
    unsigned char uchr = 0;
 
    // Code for unsigned char
 
    // Code for signed char
 
    // Code for unsigned short int
 
    // Code for signed short int
 
    // Code for unsigned int
 
    // Code for signed int
 
    // Code for unsigned long int
 
    // Code for signed long int
 
    // Code for unsigned long long int
 
    // Code for signed long long int
 
    return(0);
}

unsigned char code block

Following is provided code giving you the requested information for an unsigned char. Study it, implement it, and adapt it as needed to the other data types: 

    // Code for unsigned char
    fprintf(stdout, "TYPE: %13s, ", "unsigned char"); // What is happening here?
    fprintf(stdout, "bytes: %lu, ", sizeof(uchr));    // Why does sizeof() need %lu?
    fprintf(stdout, "low: %hhu, ",  (uchr & 0x00));   // Why 2 zeros?
    fprintf(stdout, "high: %hhu, ", (uchr | 0xFF));   // Why 2 F's?
    uchr = uchr - 1;                                   // What does this line do?
    fprintf(stdout, "qty: %hu\n",   (uchr+1));        // What is going on here?

Note that by adapting, you'll need to declare and initialize additional variables, and you may “unroll” some of the logic here to do it in more discrete steps (in fact, it may enable you to solve a couple problems that crop up).

Execution

lab46:~/src/c4eng/dtr0$ ./dtr0
TYPE: unsigned char, bytes: 1, low: 0, high: 255, qty: 256
TYPE:   signed char, bytes: X, low: X, high: X, qty: X
TYPE: unsigned short int, bytes: X, low: X, high: X, qty: X
TYPE:   signed short int, bytes: X, low: X, high: X, qty: X
...
lab46:~/src/c4eng/dtr0$

This output includes some mock additional entries, actual values abstracted. Instead of displaying 'X', your program should display the actual values, and display a total of 10 lines, for the signed and unsigned variations of the five data types we are studying in this project.

Reflection

Be sure to provide any commentary on your journal regarding realizations had and discoveries made during your pursuit of this project. You should also consider adding extra comments into your program so that it can be a more valuable reference going forward.

Also, answer the following questions:

Review of Compiling/Executing

Just to review the compilation/execution process for working with your source code, if we had a file, hello.c, that we wished to compile to a binary called hello, we'd first want to compile the code, as follows: 

lab46:~/src/c4eng/proj$ gcc -Wall --std=gnu99 -o hello hello.c
lab46:~/src/c4eng/proj$

Assuming there are no syntax errors or warnings, and everything compiled correctly, you should just get your prompt back. In the event of problems, the compiler will be sure to tell you about them.

Conceptually, the arrangement is as follows: 

gcc -Wall --std=gnu99 -o BINARY_FILE SOURCE_FILE

The BINARY_FILE comes immediately after the -o, NOT the SOURCE_FILE (it must never immediately follow a -o). It can precede, and such is perfectly valid (especially if you feel that way more intuitive).

The -Wall (treat all warnings as errors, increase general verbosity about warnings) and –std=gnu99 (switch compiler to use the C99 standard of the C language with GNU compiler extensions) are options given to the compiler.

To execute your binary, we need to specify a path to it, so we use ./, which references the current directory (the dot '.' tells the computer “my current location”, and the forward slash '/' is the directory separator): 

lab46:~/src/c4eng/proj$ ./hello
Hello, World!
lab46:~/src/c4eng/proj$

Submission Criteria

To be successful in this project, the following criteria must be met:

Submit Tool Usage

Let's say you have completed work on the project, and are ready to submit, you would do the following: 

lab46:~/src/c4eng/dtr0$ submit c4eng dtr0 dtr0.c
Submitting c4eng project "dtr0":
    -> dtr0.c(OK) 

SUCCESSFULLY SUBMITTED
lab46:~/src/c4eng/dtr0$

You should get some sort of confirmation indicating successful submission if all went according to plan. If not, check for typos and or locational mismatches.

I'll be evaluating the project based on the following criteria: 

52:dtr0:final tally of results (52/52)
*:dtr0:submitted file called dtr0.c [4/4]
*:dtr0:committed and pushed dtr0.c to repository [4/4]
*:dtr0:adequate and consistent indentation in dtr0.c [4/4]
*:dtr0:sufficient comments in dtr0.c [4/4]
*:dtr0:utilizes correct and best fit printf format specifiers [8/8]
*:dtr0:executable runs without issue [4/4]
*:dtr0:output is correct [8/8]
*:dtr0:output conforms to project specifications [8/8]
*:dtr0:adequate modifications in dtr0.c [4/4]
*:dtr0:no compiler warnings nor errors for dtr0.c [4/4]

Additionally: