ch1/

Modify the `echo` program to also allow print `os.Args[0]`, the name of the command that invoked it.

Try `fetchall` with longer argument lists, such as samples from the top million web sites available at `alexa.com`.

Modify the Lissajous server to read parameter values from the URL.

Modify the `echo` program to print the index and value of each of its arguments, one per line.

Experiment to measure the difference in running time between our potentially inefficient versions and the one that uses `strings.Join`.

Modify `dup2` to print the names of all files in which each duplicated line occurs.

Change the Lissajous program's color palette to green on black, for added authenticity.

Modify the Lissajous program to produce images in multiple colors by adding more values to `palette` and then displaying them by changing the third argument of `SetColorIndex` in some interesting way.

The function call `io.Copy(dst, src)` reads from `src` and writes to `dst`.

Modify `fetch` to add the prefix `http://` to each argument URL, if it is missing.

Modify `fetch` to also print the HTTP status code, found in `resp.Status`.