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Untar works with example

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This commit is contained in:
Jameson Little 2011-06-09 09:37:35 -06:00
parent 6c93bc1258
commit f34c1964dd
2 changed files with 134 additions and 0 deletions
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17
examples/index.html
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@ -7,6 +7,7 @@
<script src='../lib/utils.js'></script>
<script src='../lib/header.js'></script>
<script src='../lib/tar.js'></script>
<script src='../lib/untar.js'></script>
<script>
(function () {
@ -14,19 +15,35 @@
var Tar = require('tar'),
utils = require('utils'),
Untar = require('untar'),
tape = new Tar(),
out,
url,
base64;
function uint8ToString(buf) {
var i, length, out = '';
for (i = 0, length = buf.length; i < length; i += 1) {
out += String.fromCharCode(buf[i]);
}
return out;
}
out = tape.append('output.txt', 'This is test1!');
out = tape.append('dir/out.txt', 'This is test2! I changed up the directory');
out = tape.append('arr.txt', utils.stringToUint8('This is a Uint8Array!'));
Untar(out, function (header, data) {
var contents = uint8ToString(data);
console.log(header.fileName, contents);
});
/*
base64 = utils.uint8ToBase64(out);
url = "data:application/tar;base64," + base64;
window.open(url);
*/
}());
</script>
</head>

117
lib/untar.js Normal file
View file

@ -0,0 +1,117 @@
(function () {
"use strict";
var recordSize = 512;
function removePadding(buf) {
var text = '',
i, length;
for (i = 0, length = buf.length; i < buf.length; i += 1) {
text += String.fromCharCode(buf[i]);
}
return parseInt(text.replace(/^0*/, ''), 8) || 0;
}
function readString(buf) {
var text = '',
i, length;
for (i = 0, length = buf.length; i < length, buf[i] !== 0; i += 1) {
text += String.fromCharCode(buf[i]);
}
return text;
}
function doHeader(buf) {
var data = {}, offset = 0;
data.fileName = readString(buf.subarray(offset, offset + 100));
offset += 100;
data.fileMode = removePadding(buf.subarray(offset, offset + 8));
offset += 8;
data.uid = removePadding(buf.subarray(offset, offset + 8));
offset += 8;
data.gid = removePadding(buf.subarray(offset, offset + 8));
offset += 8;
data.fileSize = removePadding(buf.subarray(offset, offset + 12));
offset += 12;
data.mtime = removePadding(buf.subarray(offset, offset + 12));
offset += 12;
data.checksum = removePadding(buf.subarray(offset, offset + 8));
offset += 8;
data.type = removePadding(buf.subarray(offset, offset + 1));
offset += 1;
data.linkname = readString(buf.subarray(offset, offset + 100));
offset += 100;
data.ustar = readString(buf.subarray(offset, offset + 8));
if (/ustar/.test(data.ustar)) {
offset += 8;
data.owner = readString(buf.subarray(offset, offset + 32));
offset += 32;
data.group = readString(buf.subarray(offset, offset + 32));
offset += 32;
data.majorNumber = removePadding(buf.subarray(offset, offset + 8));
offset += 8;
data.minorNumber = removePadding(buf.subarray(offset, offset + 8));
offset += 8;
data.filenamePrefix = readString(buf.subarray(offset, offset + 155));
}
return data;
}
function doFile(buf, cb) {
var header, offset = 0, numBlocks, fileData;
header = doHeader(buf);
offset += recordSize;
numBlocks = Math.ceil(header.fileSize / recordSize);
fileData = buf.subarray(offset, offset + header.fileSize);
offset += numBlocks * recordSize;
cb(header, fileData, offset);
}
/*
* Extract data from an input.
*
* @param input- must be a buffer
* @param opts- object of options
* @param cb- callback to call on each file- params: header, fileData (uint8Array)
*/
function Untar (input, cb) {
var offset = 0;
while(input[offset]) {
doFile(input.subarray(offset), function (header, fileData, iOffset) {
offset += iOffset;
cb(header, fileData);
});
}
}
module.exports = Untar;
provide('untar', module.exports);
}());