Write a program in C that calculates the CRC-15 value for a given file and which can also verify the correctness of a given file that already has a CRC-15 value appended to it, as more fully described below.

Use the CRC polynomial: x¹⁵+x¹³+ x⁶+x⁴+x¹+1.

Program operation:

The program must compile from the command line.

The program executable file name must be crcheck.

The program must run from the command line and take two (2) command line parameters.

The first command line parameter will be a flag value that identifies the mode of operation: c for calculating a CRC value, or v for verifying a CRC value. Only these two values are allowed. Any other values should produce a simple error message and a graceful exit from the program.

The second command line parameter will be the name of the file to be examined. The file should be a text file that is in the same folder as the program executable. If the file is not found, the program should issue a simple error message and exit gracefully.

The program should direct all output to the command window (terminal) screen. The details of what to output are described below.

The program MUST run on Eustis. Please make sure to test your program on Eustis before submitting the assignment.

What to submit:

Submit a single source code file written in C, C++, or Java. No other languages are permitted.

The source code file must be a .c, .cpp, or .java file.

Put all classes, functions, and methods in the one file.

If programming in Java, do not place the source in your own package so our test scripts can run without changes.

If you are coding in C or C++, you must use only the standard libraries, such as stdio.h, math.h, and Standard Template Library.

If using Java, your source file must be named crcheck.java.

You must also submit a README file, which must be a text file, and which contains:

The compilation command for your program

The run command for your program

Your statement that the program is entirely your own work and that you have neither developed your code together with any another person, nor copied program code from any other person, nor permitted your code to be copied or otherwise used by any other person, nor have you copied, modified, or otherwise used program code that you have found in any external source, including but not limited to, online sources.

Input file format:

Valid input files will be ASCII files that contain printable data. There will be no pad or fill characters in a raw input file.

If an input file contains any invalid data (other than an end-of-file marker), then the program should issue an appropriate brief error message and terminate gracefully.

The raw input file will consist of ASCII data of varying length up to 512 bytes, with the last 8 bytes reserved for the checksum. (Note: The CRC or checksum will be a 16 bit integer, or 4 hexadecimal digits, which will fill the last 4 bytes/characters, the leading 4 characters should be zeroes.)

In the event the input file is not 504 characters (512 8) the deficiency should be padded with the . character as shown in the examples below. Note that the . character will affect the generated CRC.

Output format:

Output the ASCII file that is read, 64 characters to a line. Alphabetic characters in this output must be represented as it was read from the input file, regardless of case.

Next, you will show the result of each 64 characters lines cumulative XOR operation involved in the CRC calculation or verification. For example:

abcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345a - 0000206c

Note that the input is shown in black and the lines CRC is shown in red. (There is no need to use color in the output for the assignment.)

At the end, when calculating CRC, you must show the CRC result in hexadecimal. Please note that in the event the input file is less than 512 characters, you must pad the remainder of the output file with blank spaces reserving the last 8 characters for the ASCII representation of the CRC, with leading zeroes as needed to obtain a 16-bit value for the CRC-15 code.

On the other hand, if verifying CRC, you must output (a) the accumulated CRC value in hexadecimal at the end of each 64 character output of the input file including pad spaces and the stated hexadecimal CRC (Note that the CRC even though it is hexadecimal data it will be printed in ASCII.); (b) the CRC (hexadecimal) calculated by the program; and (c) a message whether the CRC check passed or failed.

Specific Functions inside code:

You must implement the following functions/methods:

A function/method to read the data in the input file into an array.

An XOR function/method that takes as input two 32 bit unsigned binary integers and returns the XOR result. (Java does not support 16 bit unsigned integers unless using Java 8, hence the 32 bit unsigned integer appropriately used, provides adequate bit space for the CRC calculations.)

A function/method for CRC calculation

A function/method for CRC verification

Grading Rubric

The total possible score for this program is 100 points. The following point values will be deducted for the reasons stated:

[ -100 points ] Your program does not successfully compile on Eustis from the command line with one of these commands:

C program: prompt> gcc lm o crcheck [your_file_name].c

C++ program: prompt> g++ -lm o crcheck [your_file_name].cpp

Java program: prompt> javac crcheck.java

Note: If you are submitting a Java program, the class file must be named crcheck.java and the class name must be crcheck (all lower case).

[-90] Fails during execution

[-50] Reads input file no output

[-25] Reads & displays input file produce output but with invalid or null CRC

[-0] Reads input file, produces valid output, with correct CRC and the validation option also works.

[536] mmcalpin@Hydrogen:~/UCF/CIS3360$java crcheck c WC-ngi.txt

CRC15 Input text from file

"This is the lesson: never give in, never give in, never, never,

never, never - in nothing, great or small, large or petty - nev

er give in except to convictions of honour and good sense. Never

yield to force; never yield to the apparently overwhelming migh

t of the enemy."

CRC 15 calculation progress:

"This is the lesson: never give in, never give in, never, never, - 000015fa

never, never - in nothing, great or small, large or petty - nev - 00006206

er give in except to convictions of honour and good sense. Never - 00002dd2

yield to force; never yield to the apparently overwhelming migh - 000007bf

t of the enemy."................................................ - 0000702e

................................................................ - 000024a1

................................................................ - 00005be7

........................................................00002db9 - 00002db9

CRC15 result : 00002db9

Figure 1.1 Program crcheck Calculation option

CRC15 Input text from file

"This is the lesson: never give in, never give in, never, never,

never, never - in nothing, great or small, large or petty - nev

er give in except to convictions of honour and good sense. Never

yield to force; never yield to the apparently overwhelming migh

t of the enemy."................................................

................................................................

................................................................

........................................................00002db9

CRC 15 calculation progress:

"This is the lesson: never give in, never give in, never, never, - 000015fa

never, never - in nothing, great or small, large or petty - nev - 00006206

er give in except to convictions of honour and good sense. Never - 00002dd2

yield to force; never yield to the apparently overwhelming migh - 000007bf

t of the enemy."................................................ - 0000702e

................................................................ - 000024a1

................................................................ - 00005be7

........................................................00002db9 - 00002db9

CRC15 result : 00002db9

CRC 15 verification passed

Figure 1.2 Program crcheck Verification option

CRC15 Input text from file

abcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345a

bcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345ab

cdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abc

defghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcd

efghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcde

fghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345

CRC 15 calculation progress:

abcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345a - 00001a6a

bcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345ab - 00007d1d

cdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abc - 00001fdf

defghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcd - 00000d90

efghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcde - 0000259f

fghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345...... - 00003ef2

................................................................ - 000057ad

........................................................000075dc - 000075dc

CRC15 result : 000075dc

Figure 2.1 Program crcheck Calculation option

CRC16 Input text from file

abcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345a

bcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345ab

cdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abc

defghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcd

efghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcde

fghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345......

................................................................

........................................................000075dc

CRC 15 calculation progress:

abcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345a - 00001a6a

bcdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345ab - 00007d1d

cdefghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abc - 00001fdf

defghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcd - 00000d90

efghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345abcde - 0000259f

fghijklmnopqrstuvwxyz12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ12345...... - 00003ef2

................................................................ - 000057ad

........................................................000075dc - 000075dc

CRC15 result : 000075dc

CRC 15 verification passed

Figure 2.2 Program crcheck Verification option