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Ciphering CLI Tool

Implement CLI tool that will encode and decode a text by 3 substitution ciphers:

CLI tool should accept 3 options (short alias and full name):

  1. -c, --config: config for ciphers Config is a string with pattern {XY(-)}n, where:
  • X is a cipher mark:
    • C is for Caesar cipher (with shift 1)
    • A is for Atbash cipher
    • R is for ROT-8 cipher
  • Y is flag of encoding or decoding (mandatory for Caesar cipher and ROT-8 cipher and should not be passed Atbash cipher)
    • 1 is for encoding
    • 0 is for decoding
  1. -i, --input: a path to input file
  2. -o, --output: a path to output file

For example, config "C1-C1-R0-A" means "encode by Caesar cipher => encode by Caesar cipher => decode by ROT-8 => use Atbash"

Details:

  1. The task must be solved using only pure Node.js. Any libraries and packages (except nodemon, prettier and its plugins, eslint and its plugins) are prohibited.
  2. Config option is required and should be validated. In case of invalid confing human-friendly error should be printed in stderr and the process should exit with non-zero status code.
  3. If any option is duplicated (i.e. bash $ node my_ciphering_cli -c C1-C1-A-R0 -c C0) then human-friendly error should be printed in stderr and the process should exit with non-zero status code.
  4. If the input file option is missed - use stdin as an input source.
  5. If the output file option is missed - use stdout as an output destination.
  6. If the input and/or output file is given but doesn't exist or you can't access it (e.g. because of permissions or it's a directory) - human-friendly error should be printed in stderr and the process should exit with non-zero status code.
  7. If passed params are fine the output (file or stdout) should contain transformed content of input (file or stdin).
  8. For encoding/decoding use only the English alphabet, all other characters should be kept untouched.
  9. Using streams for reading, writing and transformation of text is mandatory.
  10. Each cipher is implemented in the form of a transform stream.
  11. Streams are piped inside each other according to config (you can use .pipe streams instances method or pipeline)

Usage example:

$ node my_ciphering_cli -c "C1-C1-R0-A" -i "./input.txt" -o "./output.txt"

input.txt This is secret. Message about "_" symbol!

output.txt Myxn xn nbdobm. Tbnnfzb ferlm "_" nhteru!

$ node my_ciphering_cli -c "C1-C0-A-R1-R0-A-R0-R0-C1-A" -i "./input.txt" -o "./output.txt"

input.txt This is secret. Message about "_" symbol!

output.txt Vhgw gw wkmxkv. Ckwwoik onauv "_" wqcnad!

$ node my_ciphering_cli -c "A-A-A-R1-R0-R0-R0-C1-C1-A" -i "./input.txt" -o "./output.txt"

input.txt This is secret. Message about "_" symbol!

output.txt Hvwg wg gsqfsh. Asggous opcih "_" gmapcz!

$ node my_ciphering_cli -c "C1-R1-C0-C0-A-R0-R1-R1-A-C1" -i "./input.txt" -o "./output.txt"

input.txt This is secret. Message about "_" symbol!

output.txt This is secret. Message about "_" symbol!