NodeJS 将二进制缓冲区写入文件
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NodeJS write binary buffer into a file
提问by max246
I can't rewrite a file that I am getting from a binary buffer, I have checked with the original file and all bytes are the same.
我无法重写从二进制缓冲区获取的文件，我已经检查了原始文件并且所有字节都相同。
This is the file create from NodeJS:
这是从 NodeJS 创建的文件：
# hd test.txt | head
00000000 47 49 46 38 39 61 32 00 32 00 f7 00 00 96 8c 73 |GIF89a2.2.?....s|
00000010 66 5e 45 c6 bb 9f 7b 72 5a 47 47 47 8a 81 65 ca |f^E?.{rZGGG..e?|
00000020 c1 a6 c9 c1 ac ee ea dd c8 c5 bc 8c 87 7a d3 c9 |??????????..z??|
00000030 ab 43 3b 26 eb e5 d1 fa fa fa e5 e4 e2 a6 9d 83 |?C;&??????????..|
00000040 86 7e 67 c1 b4 8e e4 dc c6 82 82 82 e1 dd d1 e3 |.~g??.???...????|
00000050 dd ca e4 da bc f5 f1 e6 26 25 25 9c 91 73 f8 f3 |???????&%%..s??|
00000060 e4 c3 b9 9d d3 ca b4 4a 42 2a d1 c6 a2 6c 62 46 |?ù.??JB*??lbF|
00000070 ea e6 db bb b3 9c db d3 bb 5c 54 3d f1 ee e6 dc |????.??\T=????|
00000080 da d3 e7 e4 dc ce c2 9f f8 f6 f2 76 6c 53 fc fb |???????.???vlS??|
00000090 f9 e9 e1 ca 17 13 09 67 4d 00 f8 f4 e8 dc d3 b5 |????...gM.?????|
This the original one:
这是原来的：
$ hd runner_small.gif | head
00000000 47 49 46 38 39 61 32 00 32 00 f7 00 00 96 8c 73 |GIF89a2.2......s|
00000010 66 5e 45 c6 bb 9f 7b 72 5a 47 47 47 8a 81 65 ca |f^E...{rZGGG..e.|
00000020 c1 a6 c9 c1 ac ee ea dd c8 c5 bc 8c 87 7a d3 c9 |.............z..|
00000030 ab 43 3b 26 eb e5 d1 fa fa fa e5 e4 e2 a6 9d 83 |.C;&............|
00000040 86 7e 67 c1 b4 8e e4 dc c6 82 82 82 e1 dd d1 e3 |.~g.............|
00000050 dd ca e4 da bc f5 f1 e6 26 25 25 9c 91 73 f8 f3 |........&%%..s..|
00000060 e4 c3 b9 9d d3 ca b4 4a 42 2a d1 c6 a2 6c 62 46 |.......JB*...lbF|
00000070 ea e6 db bb b3 9c db d3 bb 5c 54 3d f1 ee e6 dc |.........\T=....|
00000080 da d3 e7 e4 dc ce c2 9f f8 f6 f2 76 6c 53 fc fb |...........vlS..|
00000090 f9 e9 e1 ca 17 13 09 67 4d 00 f8 f4 e8 dc d3 b5 |.......gM.......|
You can compare these two files and every bytes are the same, I am guessing that the encoding from NodeJS is not the right one.
你可以比较这两个文件，每个字节都是一样的，我猜来自 NodeJS 的编码是不正确的。
This is the piece of code
这是一段代码
var foo = "71%73%70%56%57%97%50%0%50%0%247%0%0%150%140%115%102%94%69%198%187%159%123%114%90%71%71%71%138%129%101%202%193%166%201%193%172%238%234%221%200%197%188%140$
var bytes = foo.split("%");
var b = new Buffer(bytes.length);
for (var i = 0;i < bytes.length;i++) {
b[i] = bytes[i];
}
fs.writeFile("test.txt", b, "binary",function(err) {
if(err) {
console.log(err);
} else {
console.log("The file was saved!");
}
});
You can try to run it on your NodeJS and see that the result is wrong.
你可以尝试在你的 NodeJS 上运行它，发现结果是错误的。
What can I do to fix it?
我能做些什么来修复它？
回答by Mohamed Alimam
I am not sure if this would help but try to change the b variable to the bytes variable in the line below at least you would be able to view the file in a test editor
我不确定这是否有帮助，但尝试将 b 变量更改为下面一行中的 bytes 变量，至少您可以在测试编辑器中查看该文件
fs.writeFile("test.txt", b, "binary",function(err) { });
If you would like to have the numbers space separated try the code below:
如果您想将数字空间分开，请尝试以下代码：
var fs = require('fs');
var foo = "71%73%70%56%57%97%50%0%50%0%247%0%0%150%140%115%102%94%69%198%187%159%123%114%90%71%71%71%138%129%101%202%193%166%201%193%172%238%234%221%200%197%188%140"
var bytes = foo.split("%");
var b = new Buffer(bytes.length);
var c = "";
for (var i = 0;i < bytes.length;i++) {
b[i] = bytes[i];
c = c + " " + bytes[i]
}
fs.writeFile("test.txt", c, "binary",function(err) {
if(err) {
console.log(err);
} else {
console.log("The file was saved!");
}
});
回答by Pedro Rodrigues
You can try this:
你可以试试这个：
var writeFileSync = function (path, buffer, permission) {
permission = permission || 438; // 0666
var fileDescriptor;
try {
fileDescriptor = fs.openSync(path, 'w', permission);
} catch (e) {
fs.chmodSync(path, permission);
fileDescriptor = fs.openSync(path, 'w', permission);
}
if (fileDescriptor) {
fs.writeSync(fileDescriptor, buffer, 0, buffer.length, 0);
fs.closeSync(fileDescriptor);
}
}
// then writeFileSync('path_to_your_file', your_buffer);
