Exemplo1

gulpfile.js

var gulp = require("gulp");
var sass = require("gulp-sass");

gulp.task("compilar-css", function(){
    return gulp.src("./source/sass/*.scss")
           .pipe(sass())
           .pipe(gulp.dest("./dist/css"));
});

gulp.task('mova', function(){
    return gulp.src("./dist/css/style.css")
           .pipe(gulp.dest("./outro/css"))
});

gulp.task("escuta-me", function(){
    gulp.watch('./source/sass/*.scss',['compilar-css']);
});