Simple 32-Bit Checksum

Project: Simple 32-Bit Checksum

Write a program that computes a simple checksum. Checksums are a way to convert a large amount of data down to one number. If we compute the checksum before we transmit a file over the network then compute the checksum of the received file we will hopefully notice a change in the checksum value if the data was corrupted during transmission.

The program should take input on the standard input and compute a 32-bit checksum of the data. The checksum is computed taking the input bytes four at a time to form a 32-bit value (network byte order or big endian). This value is XORed with the current value of the checksum. The checksum should start with 0. Once the input is exhausted the program should print out the checksum as eight hexidecimal digits.

Output

$ swiftc SimpleChecksum2.swift -I . -L . -lUtils error: link command failed with exit code 1 (use -v to see invocation) ld: library not found for -lUtils clang: error: linker command failed with exit code 1 (use -v to see invocation) $ swiftc SimpleChecksum2.swift -I . -L . -lUtils error: link command failed with exit code 1 (use -v to see invocation) ld: library not found for -lUtils clang: error: linker command failed with exit code 1 (use -v to see invocation) $ swiftc SimpleChecksum2.swift -I . -L . -lUtils error: link command failed with exit code 1 (use -v to see invocation) ld: library not found for -lUtils clang: error: linker command failed with exit code 1 (use -v to see invocation)

Solution