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@notslang
Last active April 4, 2016 02:31
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Multihash CLI in coffeescript
base58 = require 'bs58'
{ArgumentParser} = require 'argparse'
packageInfo = require '../package'
multihash = require '../src'
printJSON = (obj) ->
# print out one key/value per line, so (for example) piping into `wc -l` gives
# a count of the total supported functions
console.log JSON.stringify(obj, null, 1).replace(/\s*(\}|\{)\s*/gm, '$1')
return
encodingOption = (parser) ->
parser.addArgument(
['--encoding']
type: 'string'
choices: ['ascii', 'base58', 'base64', 'binary', 'hex', 'utf16le', 'utf8']
help: "The encoding of MULTIHASH. Defaults to base58."
defaultValue: 'base58'
)
argparser = new ArgumentParser(
addHelp: true
description: packageInfo.description
version: packageInfo.version
)
subcommands = argparser.addSubparsers(dest: 'subcommand')
subcommand = subcommands.addParser(
'names'
description: 'Print out supported hash functions and their associated codes.'
addHelp: true
)
subcommand = subcommands.addParser(
'decode'
description: 'Validate and decode the supplied MULTIHASH. Digest is output in
hex.'
addHelp: true
)
encodingOption(subcommand)
subcommand.addArgument(
['multihash']
type: 'string'
metavar: 'MULTIHASH'
)
subcommand = subcommands.addParser(
'encode'
description: 'Encode the supplied digest and hash function into a MULTIHASH'
addHelp: true
)
subcommand.addArgument(
['--fn']
type: 'string'
help: 'Hash function used to generate DIGEST. Defaults to sha2-256.'
choices: Object.keys(multihash.names)
defaultValue: 'sha2-256'
)
encodingOption(subcommand)
subcommand.addArgument(
['digest']
type: 'string'
help: 'The digest generated by the supplied hash function, encoded in hex.'
metavar: 'DIGEST'
)
argv = argparser.parseArgs()
switch argv.subcommand
when 'names'
printJSON(multihash.names)
when 'decode'
buf = (
if argv.encoding is 'base58'
new Buffer(base58.decode(argv.multihash))
else
new Buffer(argv.multihash, argv.encoding)
)
try
info = multihash.decode(buf)
catch error
console.error error.message
process.exit(1)
info.digest = info.digest.toString('hex')
printJSON(info)
when 'encode'
try
buf = multihash.encode(new Buffer(argv.digest, 'hex'), argv.fn)
catch error
console.error error.message
process.exit(1)
console.log(
if argv.encoding is 'base58'
base58.encode(buf)
else
buf.toString(argv.encoding)
)
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