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