Simple Gulp plugin.

First, install gulp-append-prepend as a development dependency:

npm install gulp-append-prepend --save-dev

Then, add it to your gulpfile.js:

const gap = require('gulp-append-prepend');

gulp.task('myawesometask', function(){
    gulp.src('index.html')
        .pipe(gap.prependFile('header.html'))
        .pipe(gap.prependText('<!-- HEADER -->'))
        .pipe(gap.appendText('<!-- FOOTER -->'))
        .pipe(gap.appendFile('footer.html'))
        .pipe(gulp.dest('www/'));
});

This example works with html but you can use any type of file.

• appendFile(filepath, separator) The filepath can be an array. The separator is optional by default is "\n".
• prependFile(filepath, separator) The filepath can be an array. The separator is optional by default is "\n".
• appendText(text, separator) The text can be an array. The separator is optional by default is "\n".
• prependText(text, separator) The text can be an array. The separator is optional by default is "\n".

This plugin is released under the MIT licence.

I am sorry for my poor English. Feel free to make changes in this README.