Reference specifications and implementations

[shadowspawn]

I was thinking about what to consult for command-line parsing behaviours which people using the Node.js eco-system are likely to encounter.

The two specifications I am aware of are:

• POSIX which supports short options only, options must come before positional
  • https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html#tag_12_01
  • https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap12.html
• GNU adds long options, adds mixed order options and positionals
  • https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html
  • https://www.gnu.org/prep/standards/html_node/Command_002dLine-Interfaces.html

With reference implementations for C programs:

• getopt (short options only)
• getopt_long

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In Javascript world, we can look at npm dependencies as one measure of usage. Packages with over 1000 dependents (on 2022-03-06):

dependants	package
61k	commander
28k	yargs (uses yargs-parser as engine)
19k	minimist
6k	meow (uses yargs-parser as engine)
4k	@oclif/command
2k	command-line-args
2k	yargs-parser
2k	argparse
1k	nopt

• minimist and yargs share the same roots
• minimist is in maintenance mode.
• assuming yargs and yargs-parser are distinct for counts

For a second source for usage, this just came out: Census II of Free and Open Source Software — Application Libraries

In the top 500 npm packages as direct dependencies:

z-score	package	rank
2.2	commander	23
2.1	minimist	28
1.1	yargs	73
1.1	yargs-parser	75
1.1	@radic/yargs (?)	77
0.3	nopt	212
0.05	argparse	344

Across both measures, commander and yargs and minimist are the big 3 covering the majority of direct dependencies.