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using -format for identify to get more robust results #35

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using -format for identify to get more robust results #35

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189c545
using identify -format to get more robust results
naltatis Mar 9, 2012
648dae3
fixed exec to make it work with node > 0.8
naltatis Sep 11, 2012
fda27fe
make it work with node > 1.0.0, on version 4.2.0 it eventually sent e…
proll Nov 7, 2015
1e39bb1
Merge pull request #1 from proll/master
naltatis Nov 16, 2015
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175 changes: 43 additions & 132 deletions imagemagick.js
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@@ -1,139 +1,48 @@
var childproc = require('child_process'), var spawn = require('child_process').spawn,
EventEmitter = require('events').EventEmitter; EventEmitter = require('events').EventEmitter,

StringDecoder = require('string_decoder').StringDecoder;


function exec2(file, args /*, options, callback */) { // based on https://github.com/bahamas10/node-exec
var options = { encoding: 'utf8' function exec2(program, args, opts, callback) {
, timeout: 0 var out = '',
, maxBuffer: 500*1024 err = '',
, killSignal: 'SIGKILL' code,
, output: null i = 0,
}; decoder = new StringDecoder(),

v = process.version.split('.'),
var callback = arguments[arguments.length-1]; version_major = v[0],
if ('function' != typeof callback) callback = null; version_minor = v[1];


if (typeof arguments[2] == 'object') { if (typeof opts === 'function') {
var keys = Object.keys(options); callback = opts;
for (var i = 0; i < keys.length; i++) { opts = null;
var k = keys[i];
if (arguments[2][k] !== undefined) options[k] = arguments[2][k];
}
}

var child = childproc.spawn(file, args);
var killed = false;
var timedOut = false;

var Wrapper = function(proc) {
this.proc = proc;
this.stderr = new Accumulator();
proc.emitter = new EventEmitter();
proc.on = proc.emitter.on.bind(proc.emitter);
this.out = proc.emitter.emit.bind(proc.emitter, 'data');
this.err = this.stderr.out.bind(this.stderr);
this.errCurrent = this.stderr.current.bind(this.stderr);
};
Wrapper.prototype.finish = function(err) {
this.proc.emitter.emit('end', err, this.errCurrent());
};

var Accumulator = function(cb) {
this.stdout = {contents: ""};
this.stderr = {contents: ""};
this.callback = cb;

var limitedWrite = function(stream) {
return function(chunk) {
stream.contents += chunk;
if (!killed && stream.contents.length > options.maxBuffer) {
child.kill(options.killSignal);
killed = true;
}
};
};
this.out = limitedWrite(this.stdout);
this.err = limitedWrite(this.stderr);
};
Accumulator.prototype.current = function() { return this.stdout.contents; };
Accumulator.prototype.errCurrent = function() { return this.stderr.contents; };
Accumulator.prototype.finish = function(err) { this.callback(err, this.stdout.contents, this.stderr.contents); };

var std = callback ? new Accumulator(callback) : new Wrapper(child);

var timeoutId;
if (options.timeout > 0) {
timeoutId = setTimeout(function () {
if (!killed) {
child.kill(options.killSignal);
timedOut = true;
killed = true;
timeoutId = null;
}
}, options.timeout);
} }
var child = spawn(program, args, opts);


child.stdout.setEncoding(options.encoding); child.stdout.on('data', function(data) {
child.stderr.setEncoding(options.encoding); out += decoder.write(data);
});
child.stderr.on('data', function(data) {
err += decoder.write(data);
});


child.stdout.addListener("data", function (chunk) { std.out(chunk, options.encoding); }); child.on('exit', function(c) {
child.stderr.addListener("data", function (chunk) { std.err(chunk, options.encoding); }); code = c;
if (++i >= 2 || (version_major === 0 && version_minor < 8)) callback(err, out, code);
});


child.addListener("exit", function (code, signal) { child.on('close', function() {
if (timeoutId) clearTimeout(timeoutId); if (++i >= 2) callback(err, out, code);
if (code === 0 && signal === null) {
std.finish(null);
} else {
var e = new Error("Command "+(timedOut ? "timed out" : "failed")+": " + std.errCurrent());
e.timedOut = timedOut;
e.killed = killed;
e.code = code;
e.signal = signal;
std.finish(e);
}
}); });


return child; return child;
}; };



// see http://www.imagemagick.org/script/escape.php for formatting options
function parseIdentify(input) {
var lines = input.split("\n"),
prop = {},
props = [prop],
prevIndent = 0,
indents = [indent],
currentLine, comps, indent;

lines.shift(); //drop first line (Image: name.jpg)

for (i in lines) {
currentLine = lines[i];
if (currentLine.length > 0) {
indent = currentLine.search(/\S/);
comps = currentLine.split(': ');
if (indent > prevIndent) indents.push(indent);
while (indent < prevIndent) {
indents.pop();
prop = props.pop();
prevIndent = indents[indents.length - 1];
}
if (comps.length < 2) {
props.push(prop);
prop = prop[currentLine.split(':')[0].trim().toLowerCase()] = {};
} else {
prop[comps[0].trim().toLowerCase()] = comps[1].trim()
}
prevIndent = indent;
}
}
return props[0];
};

exports.identify = function(pathOrArgs, callback) { exports.identify = function(pathOrArgs, callback) {
var isCustom = Array.isArray(pathOrArgs), var isCustom = Array.isArray(pathOrArgs),
isData, isData,
args = isCustom ? ([]).concat(pathOrArgs) : ['-verbose', pathOrArgs]; args = isCustom ? ([]).concat(pathOrArgs) : ['-format', '%m %w %h %z %Q', pathOrArgs];


if (typeof args[args.length-1] === 'object') { if (typeof args[args.length-1] === 'object') {
isData = true; isData = true;
Expand All @@ -151,14 +60,16 @@ exports.identify = function(pathOrArgs, callback) {
if (isCustom) { if (isCustom) {
result = stdout; result = stdout;
} else { } else {
result = parseIdentify(stdout); var v = stdout.trim().split(' ');
geometry = result['geometry'].split(/x/); result = {

format: v[0],
result.format = result.format.match(/\S*/)[0] width: parseInt(v[1]),
result.width = parseInt(geometry[0]); height: parseInt(v[2]),
result.height = parseInt(geometry[1]); depth: parseInt(v[3])
result.depth = parseInt(result.depth); };
if (result.quality !== undefined) result.quality = parseInt(result.quality) / 100; if (v[4] !== "0") {
result.quality = parseInt(v[4]) / 100;
}
} }
} }
callback(err, result); callback(err, result);
Expand Down