check

Homework (Code)
In this part of the homework, you’ll write some of your own code to
implement various checksums.
Questions
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1. Write a short C program (called check-xor.c) that computes an
XOR-based checksum over an input file, and prints the checksum as
output. Use a 8-bit unsigned char to store the (one byte) checksum.
Make some test files to see if it works as expected.
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2. Now write a short C program (called check-fletcher.c) that
computes the Fletcher checksum over an input file. Once again,
test your program to see if it works.
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3. Now compare the performance of both: is one faster than the other?
How does performance change as the size of the input file changes?
Use internal calls to gettimeofday to time the programs. Which
should you use if you care about performance? About checking
ability?
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4. Read about the 16-bit CRC and then implement it. Test it on a number of different inputs to ensure that it works. How is its performance as compared to the simple XOR and Fletcher? How about
its checking ability?
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5. Now build a tool (create-csum.c) that computes a single-byte
checksum for every 4KB block of a file, and records the results in
an output file (specified on the command line). Build a related tool
(check-csum.c) that reads a file, computes the checksums over
each block, and compares the results to the stored checksums stored
in another file. If there is a problem, the program should print that
the file has been corrupted. Test the program by manually corrupting the file