wathc_phplog.gulpfile.js

var gulp  = require("gulp");
var process = require('child_process');
gulp.task('send', function(){
    process.exec('/home/x/bin/sendtokaifa',
        function (error, stdout, stderr) {
            if (error !== null) {
                console.log('[send]exec error: ' + error);
            }else{
                console.log("send finished");
            }
        }
    );
});
// Rerun tasks whenever a file changes.
gulp.task('watch', function() {
    gulp.watch("/var/log/php/php-error.log", ["send"]);
});

gulp.task('default', ['watch']);