Does node.js have anything like file and line like the c++ preprocessor macros?

Question

I'm working on enhancing logging in some node.js applications. In the past have used C++'s __ file__ and __ line __ preprocessor macros to help us track down issues when logging events. I haven't found anything similar to it in the node.js world.

Does anyone have suggestions or know how I can get line number and file name in node.js for logging purposes?

I'm looking for something like:

console.log(__FILE__ + "." + __LINE__ + "\t" + new Date().toISOString() + " Message ");

score 16 · Answer 1 · edited May 23 '17 at 12:02

16

see the global object:

__filename

for the lineNumber see this post: javascript node.js getting line number in try catch?

edited May 23 '17 at 12:02

Community

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answered Nov 27 '12 at 20:20

hereandnow78

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score 9 · Accepted Answer · edited May 23 '17 at 12:10

9

See: Accessing line number in V8 JavaScript (Chrome & Node.js)

Then for a filename:

Object.defineProperty(global, '__file', {
  get: function(){
    return __stack[1].getFileName().split('/').slice(-1)[0];
  }
});

You could also just use the process.argv[1] instead of calling the __stack getter but I wanted to keep it similar.

edited May 23 '17 at 12:10

Community

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answered Nov 27 '12 at 20:15

travis

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score 4 · Answer 3 · answered Jan 23 '14 at 04:32

4

Expanded on the previous answers a bit into here: https://gist.github.com/gavinengel/8572856

Allows setting globals: __line, __file, __ext, __dir

By the way, how do I create?: __function, __method, __class

answered Jan 23 '14 at 04:32

Gavin

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Thanks for the gist. You should consider making this into a node module, it could be a nice npm module – jeremy Jan 23 '14 at 15:13
Sure. Actually, I'd recommend you check out this code which I just realized was out there by the PHPJS team: https://github.com/kvz/phpjs/tree/master/experimental/language – Gavin Jan 25 '14 at 06:10

score 2 · Answer 4 · answered Feb 26 '13 at 16:36

2

Just use the C preprocesor, adds an extra build step to your code but then it allows stripping out your logging for production code.

answered Feb 26 '13 at 16:36

Jim

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1

Not a bad idea. Never thought about that. – Marc DiMillo Feb 21 '16 at 05:15
1

Sounds good, but how, exactly does one "just use the C preprocessor"? – clozach Sep 28 '21 at 01:18

Does node.js have anything like file and line like the c++ preprocessor macros?

4 Answers4

Linked

Does node.js have anything like __file__ and __line__ like the c++ preprocessor macros?

4 Answers4

Linked

Does node.js have anything like file and line like the c++ preprocessor macros?