arlib

arlib

Andras' Library of Handy Utilities

This is a placeholder for some of the code I've been working on that I want easy access to. Feel free to browse and use!

Note: qfgets which first appeared here was moved into its own package.

Contents

The components are all available with require('arlib'), or each component is loadable separately with eg require('arlib/tempnam').

tempnam( [directory], [prefix] )

php tempnam equivalent, creates a filename that does not exist on the system. Like php, it also creates the file to prevent the name from being reused.

    var tempnam = require('arlib/tempnam');
    var filename = tempnam("/usr/tmp", "filename-prefix-");
    // /usr/tmp/filename-prefix-a7259b

getopt( argv, optspec )

traditional unix command option extractor, returns an object with the options set as properties. Like traditional unix, getopt only checks for option switches at the beginning of the argument list, before non-switch arguments. It recognizes '-' as a filename and '--' as the special marker that stops further argument scanning.

    var getopt = require('arlib/getopt').getopt;
    var options = getopt(process.argv, "f:h");
    // { f: 'filename', h: true }
    var options = getopt(process.argv, "(-file):(-help)");
    // {file: 'filename', help: true}

mongoid( ), new MongoId().fetch( )

very fast, light-weight mongodb compatible timestamped unique id generator. Can be used as a convenience function to return unique-ish (random) ids, or as an id factory configured with a unique system id to return locale-specific guaranteed unique ids.

    // convenience function, picks a random system id
    var mongoid = require('arlib/mongoid');
    id = mongoid();                 // 543f376340e2816497000001
    id = mongoid();                 // 543f376340e2816497000002

    // id factory, configured for the system identifier 4656 (0x001230)
    var MongoId = require('arlib/mongoid').MongoId;
    var idFactory = new MongoId(4656);
    id = idFactory.fetch();         // 543f3789001230649f000001
    id = idFactory.fetch();         // 543f3789001230649f000002

MongoId.getTimestamp( idString )

return the timestamp from the mongoid string in JavaScript format. Note that JavaScript timestamps have millisecond precision, but mongoid only stores seconds precision, so the last 3 digits will be 000.

    MongoId.getTimestamp("543f3789001230649f000001")
    // => 1413429129000

MongoId.parse( idString )

return the mongoid string split into its component fields.

    MongoId.parse("5451a297f7e0f13c3a000001")
    // => { timestamp: 1414636183, machineid: 16244977, pid: 15418, sequence: 1 }

Note that the timestamp field is a Unix timestamp (seconds since epoch), while getTimestamp() returns a JavaScript timestamp (milliseconds since epoch).

phpdate( format, timestamp )

return a formatted date string like PHP's date() does. Supports most of the conversions (but not the ISO-8601), though timezone and localization support is rather lacking. North America timezones should work.

See php's date for the list of supported conversions. Of the conversions as of 2014-09-15 (php 5.1.0), W and o are not yet implemented.

    var phpdate = require('arlib/phpdate');
    phpdate('Y-m-d H:i:s.u T');     // 2014-10-18 04:56:53.437000 EDT

str_repeat( string, count )

return the string concatenated with itself count times. See php's str_repeat

    var str_repeat = require('arlib/str_repeat');
    str_repeat("x", 5);             // "xxxxx"

timeit( count, function, [message], [callback] )

run the function count + 1 times, and print the run timings to the console. If function is a string it will be eval-d. The function under test is run twice to compile it (and not include the cost of compilation in the timings) and prime the node optimizer, then count times back-to-back for the benchmark.

    var timeit = require('arlib/timeit');
    var fs = require('fs');

    function opencloseSync() {
        var fd = fs.openSync('/etc/motd', 'r');
        fs.closeSync(fd);
    }
    timeit(10000, function(){ opencloseSync(); });
    // AR: "function (){ opencloseSync(); }": 10000 loops in 0.0210 sec:  475221.68 / sec, 0.00210 ms each

    function opencloseAsync(cb) {
        fs.open('/etc/motd', 'r', function(err, fd) {
            if (err) throw err;
            fs.close(fd, function(err) { cb(fd); });
        });
    }
    timeit(10000, function(cb){ opencloseAsync(function(){ cb(); }); }, "async open/close:", function(){ });
    // async open/close: "function (cb){ opencloseAsync(function(){ cb(); }); }": 10000 loops in 0.2890 sec:  34598.11 / sec, 0.02890 ms each

http_build_query( objectOrArray, options )

format a query string like PHP's http_build_query. In particular, it handles nested objects and nested arrays.

    var http_build_query = require('arlib/http_build_query');
    var params = {a: 1, b: 2, c: [3, 4, [5, 6]]};
    var queryString = http_build_query(params, {leave_brackets: true});
    // => "a=1&b=2&c[0]=3&c[1]=4&c[2][0]=5&c[2][1]=6"

    var params = {d: {a: 1, b: 2, c: {a: 1, b: 2}}};
    var queryString = http_build_query(params, {leave_brackets: true});
    // => "d[a]=1&d[b]=2&d[c][a]=1&d[c][b]=2"

    var params = [1, 2, 3];
    var queryString = http_build_query(params, {numeric_prefix: 'idx'});
    // => "idx0=1&idx1=2&idx2=3"

options:

    arg_separator   '&'
    eq_sign         '='
    numeric_prefix  string to prepend to numeric keys
    encoding        'PHP_QUERY_RFC1738' (default) - encode spaces as '+'
                    'PHP_QUERY_RFC3986' - encode spaces as '%20'
    leave_brackets  encode {a:[3]} as "a[0]=3" and not "a%5B0%5D=3"