add maxBuffer option

[sojournerc]

running jetty using bgShell, occasionally the process is killed with the following error:

Error: stdout maxBuffer exceeded.

It would be optimal to have a maxBuffer option to avoid this issue.

[re1ro]

Hey! Could you please provide your grunt config to research the problem?

[sojournerc]

Exceeding the buffer only happens occasionally, generally depending on the logging level of jetty. Option bg: true for the watch command was blocking and jetty would not run, hence: "cmd: 'grunt watch &\n mvn -Pjetty-run'".

module.exports = function (grunt) {
    grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('grunt-contrib-less');
    grunt.loadNpmTasks('grunt-bg-shell');

    grunt.initConfig({
        watch: {
            css: {
                files: ['**/*.less', '**/*.css', '!target/**/*'],
                tasks: ['less']
            }
        },
        less: {
            development: {
                options: {
                    paths: ["css"],
                    dumpLineNumbers: 'mediaquery'
                },
                files: {
                    "target/compiled/css/main.css": "src/main/webapp/less/main.less"
                }
            }
        },
        // background shell utility
        bgShell: {
            runMavenWatchLess: {
                cmd: 'grunt watch &\n mvn -Pjetty-run'
            }
        }
    });
    // default task
    grunt.registerTask('default', ['develop']);
    grunt.registerTask('develop', ['target','less:development','bgShell:runMavenWatchLess']);

    grunt.registerTask('target', 'creates the target directory for less compile', function () {
        grunt.file.mkdir('target/compiled/css');
    });
};  

[re1ro]

You can solve the problem setting execOpts: maxBuffer to NaN or Infinity. You can see how it works in source code

[davidmccabe]

In what way is allocating memory forever a solution?

[re1ro]

If you want to run a command line tool with lots of output for a long time, for example.

[davidmccabe]

If you want to run a command line tool with a lot of output for a long time — you can't, because you'll run out of memory. While capturing the output of a subprocess can be useful, grunt is frequently used to run server processes, and so the default should be to not crash by discarding output periodically.

[re1ro]

That's just the way how child_process.exec works. You can see how it adds data chunks to buffer here. If you want to run your process forever I need to reimplement 'child_process.execFile' without keeping buffer

[re1ro]

@sojournerc @davidmccabe You can set execOpts.maxBuffer to false, 0, NaN or Infinite. But it won't buffer stdout and stderr for done callback

[re1ro]

Fixed in v2.2.0

[davidmccabe]

Thanks for fixing this!