/*
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* extsprintf.js: extended POSIX-style sprintf
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*/
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var mod_assert = require('assert');
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var mod_util = require('util');
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/*
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* Public interface
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*/
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exports.sprintf = jsSprintf;
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exports.printf = jsPrintf;
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exports.fprintf = jsFprintf;
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/*
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* Stripped down version of s[n]printf(3c). We make a best effort to throw an
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* exception when given a format string we don't understand, rather than
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* ignoring it, so that we won't break existing programs if/when we go implement
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* the rest of this.
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*
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* This implementation currently supports specifying
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* - field alignment ('-' flag),
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* - zero-pad ('0' flag)
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* - always show numeric sign ('+' flag),
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* - field width
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* - conversions for strings, decimal integers, and floats (numbers).
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* - argument size specifiers. These are all accepted but ignored, since
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* Javascript has no notion of the physical size of an argument.
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*
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* Everything else is currently unsupported, most notably precision, unsigned
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* numbers, non-decimal numbers, and characters.
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*/
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function jsSprintf(fmt)
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{
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var regex = [
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'([^%]*)', /* normal text */
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'%', /* start of format */
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'([\'\\-+ #0]*?)', /* flags (optional) */
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'([1-9]\\d*)?', /* width (optional) */
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'(\\.([1-9]\\d*))?', /* precision (optional) */
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'[lhjztL]*?', /* length mods (ignored) */
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'([diouxXfFeEgGaAcCsSp%jr])' /* conversion */
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].join('');
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var re = new RegExp(regex);
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var args = Array.prototype.slice.call(arguments, 1);
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var flags, width, precision, conversion;
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var left, pad, sign, arg, match;
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var ret = '';
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var argn = 1;
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mod_assert.equal('string', typeof (fmt));
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while ((match = re.exec(fmt)) !== null) {
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ret += match[1];
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fmt = fmt.substring(match[0].length);
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flags = match[2] || '';
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width = match[3] || 0;
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precision = match[4] || '';
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conversion = match[6];
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left = false;
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sign = false;
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pad = ' ';
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if (conversion == '%') {
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ret += '%';
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continue;
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}
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if (args.length === 0)
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throw (new Error('too few args to sprintf'));
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arg = args.shift();
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argn++;
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if (flags.match(/[\' #]/))
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throw (new Error(
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'unsupported flags: ' + flags));
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if (precision.length > 0)
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throw (new Error(
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'non-zero precision not supported'));
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if (flags.match(/-/))
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left = true;
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if (flags.match(/0/))
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pad = '0';
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if (flags.match(/\+/))
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sign = true;
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switch (conversion) {
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case 's':
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if (arg === undefined || arg === null)
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throw (new Error('argument ' + argn +
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': attempted to print undefined or null ' +
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'as a string'));
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ret += doPad(pad, width, left, arg.toString());
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break;
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case 'd':
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arg = Math.floor(arg);
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/*jsl:fallthru*/
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case 'f':
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sign = sign && arg > 0 ? '+' : '';
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ret += sign + doPad(pad, width, left,
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arg.toString());
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break;
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case 'x':
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ret += doPad(pad, width, left, arg.toString(16));
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break;
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case 'j': /* non-standard */
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if (width === 0)
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width = 10;
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ret += mod_util.inspect(arg, false, width);
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break;
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case 'r': /* non-standard */
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ret += dumpException(arg);
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break;
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default:
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throw (new Error('unsupported conversion: ' +
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conversion));
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}
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}
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ret += fmt;
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return (ret);
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}
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function jsPrintf() {
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var args = Array.prototype.slice.call(arguments);
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args.unshift(process.stdout);
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jsFprintf.apply(null, args);
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}
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function jsFprintf(stream) {
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var args = Array.prototype.slice.call(arguments, 1);
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return (stream.write(jsSprintf.apply(this, args)));
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}
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function doPad(chr, width, left, str)
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{
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var ret = str;
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while (ret.length < width) {
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if (left)
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ret += chr;
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else
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ret = chr + ret;
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}
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return (ret);
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}
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/*
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* This function dumps long stack traces for exceptions having a cause() method.
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* See node-verror for an example.
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*/
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function dumpException(ex)
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{
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var ret;
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if (!(ex instanceof Error))
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throw (new Error(jsSprintf('invalid type for %%r: %j', ex)));
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/* Note that V8 prepends "ex.stack" with ex.toString(). */
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ret = 'EXCEPTION: ' + ex.constructor.name + ': ' + ex.stack;
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if (ex.cause && typeof (ex.cause) === 'function') {
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var cex = ex.cause();
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if (cex) {
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ret += '\nCaused by: ' + dumpException(cex);
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}
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}
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return (ret);
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}
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