.TH "opts.js" "3"
.PP
Find the full documentation, source code, and examples at \fIhttps://khtdr.com/opts\fP

.SH "NAME"
.PP
opts.js - a command line parser for options and arguments

.SH "VERSION"
.PP
v2.0.2

.SH "SYNOPSIS"
.PP
The following example uses a custom \fBversion\fP function, and opts in to the automatic help text. No pun intended.

.RS
.nf
\fCvar opts = require('opts');

var options = [
  { short       : 'v'
  , long        : 'version'
  , description : 'Show version and exit'
  , callback    : function () { console.log('v1.0'); process.exit(1); }
  }
];

opts.parse(options, true);
console.log('Example 1');
process.exit(0);
\fP
.fi
.RE
.PP
See \fIhttps://raw.githubusercontent.com/khtdr/opts/master/examples/example1.js\fP

.SS "running:"
.RS
.nf
\fC$ node ./example1
\fP
.fi
.RE
.SS "produces:"
.RS
.nf
\fCExample 1
\fP
.fi
.RE

.SS "running:"
.RS
.nf
\fC$ node ./example1 --help
\fP
.fi
.RE
.SS "produces:"
.RS
.nf
\fCUsage: node ./example1 [options]
Show this help message
   --help
Show version and exit
   -v, --version
\fP
.fi
.RE

.SS "running:"
.RS
.nf
\fCnode ./example1 -v
\fP
.fi
.RE
.SS "produces:"
.RS
.nf
\fCv1.0
\fP
.fi
.RE



.SH "INSTALLATION"
.PP
You do not need to use NPM or any package manager. It is written in plain-old Javascript and can be downloaded and included in your Node.js project, as-is. All of the examples use this approach.
.RE
See \fIhttps://github.com/khtdr/opts/tree/master/examples\fP

.SS "Stand-alone version"
.RS
.nf
\fCcd /path/to/your/project
curl -o opts.js https://raw.githubusercontent.com/khtdr/opts/master/src/opts.js
\fP
.fi
.RE

.SS "NPM version"
.RS
.nf
\fCnpm install opts
\fP
.fi
.RE

.SH "USAGE"
.SS "LOADING"
.PP
With classic syntax:
.RS
.nf
\fCvar opts = require('opts');
opts.parse(options, arguments, help);
\fP
.fi
.RE

.PP
With modern syntax:
.RS
.nf
\fCimport * as opts from 'opts';
opts.parse(options, arguments, help);
\fP
.fi
.RE

.PP
If you installed \fCopts\fP with NPM, the typescript definitions should automatically be available in your editor. Otherwise you can download the .d.ts file manually.
.RE
See \fIhttps://raw.githubusercontent.com/khtdr/opts/master/src/opts.d.ts\fP

.SS "CONFIGURING"
.PP
\fIopts.parse(options, arguments, help)\fP

.PP
Options are flag-arguments. Arguments are everything else. Consider the following hypothetical command for starting a server that listens on \fIhttp://0.0.0.0:4000\fP

.RS
.nf
\fCnode ./my-app start --host 0.0.0.0 -p 4000
\fP
.fi
.RE

.PP
In this example, the options are \fI\-\-host 0.0.0.0\fP and \fI\-p 4000\fP. The argument is \fIstart\fP. The arguments can be after, before, or among the options.

.SS "options"
.PP
\fCoptions\fP is an array of option objects. Each option in the array can have the following fields. None are required, but you should at least provide a short or long name.

.RS
.nf
\fClet options = [
  { short       : 'l',
    long        : 'list',
    description : 'Show a list',
    value       : false, // default false
    required    : true, // default false
    callback    : function (value) { ... },
  }, // ... followed by more options
];
\fP
.fi
.RE

.SS "arguments"
.PP
\fCarguments\fP require less configuration. This is an optional argument to \fCopts.parse\fP:

.RS
.nf
\fClet arguments =
  { name     : 'script',
    required : true, // not required by default
    callback : function (value) { ... },
  };
\fP
.fi
.RE

.SS "help text generator"
.PP
Finally, you can add an automatically generated help message by passing
a last parameter of \fItrue\fP. This is also an optional argument to \fCopts.parse\fP.

.RS
.nf
\fCopts.parse(options, true);
// or if you want more control, you can do:
/*
  options.push({
    long        : 'help',
    description : 'Show this help message',
    callback    : require('opts').help,
  }
  opts.parse(options);
*/
\fP
.fi
.RE



.SH "AUTHOR / CHANGELOG / LICENSE"
.PP
Email: ohkay@khtdr.com

.PP
Relatively unchanged since 2010.
.RE
See \fIhttps://github.com/khtdr/opts/blob/master/CHANGES.org\fP

.PP
BSD 2-Clause License
.RE
See \fIhttps://github.com/khtdr/opts/blob/master/LICENSE\fP