exit-on-epipe
Cleanly exit on pipe errors in NodeJS scripts.
NOTE: The underlying problem was addressed in 8.x NodeJS versions but the fix was not backported to 6.x and other versions of NodeJS.
These errors are common in pipelines that involve NodeJS scripts. For example, take a simple script that prints out 10 lines:
for(var i = 0; i < 10; ++i) console.log(i)
NodeJS will print an error message if the output is truncated:
$ cat t.js
for(var i = 0; i < 10; ++i) console.log(i)
$ node --version
v6.11.1
$ node t.js | head -n 1
0
events.js:160
throw er; // Unhandled 'error' event
^
Error: write EPIPE
at exports._errnoException (util.js:1018:11)
at WriteWrap.afterWrite (net.js:800:14)
The process will cleanly exit if you require the module:
$ cat t.js
require("exit-on-epipe");
for(var i = 0; i < 10; ++i) console.log(i)
$ node t.js | head -n 1
0
Installation
With npm:
$ npm install exit-on-epipe
Usage
For basic scripts, requiring at the top of the source file suffices:
require('exit-on-epipe');
// ... rest of source
For more advanced situations (e.g. handing other streams), call the module:
var eoepipe = require('exit-on-epipe');
eoepipe(stream); // will exit process on an EPIPE error on stream
eoepipe(stream, handler); // will call handler() instead of process.exit
Interface
The module exports a single function (exposed as the variable eoepipe
).
eoepipe(stream, bail)
will attach an error handler to stream
which will:
- call the
bail
function if the error.code
is"EPIPE"
or.errno
is32
- defer to the default behavior if there are no other error handlers
- noop if the error is not
EPIPE
and if there are other error handlers
If the bail
function is not specified, process.exit
is used.
If the stream
parameter is not specified, no action will be taken
Notes
The script will not perform any action if process
or process.stdout
are not available. It is safe to use in a web page.
License
Please consult the attached LICENSE file for details. All rights not explicitly granted by the Apache 2.0 license are reserved by the Original Author.