Luke Sampson

Run a web server in one line of Powershell

Tue, 22 Nov 2022 20:32:22 -1200

Here’s how to serve a static single page website in one line of Powershell.

while(1) { cat index.html | nc -w1 -l -p 8080 }

Where index.html is the file you want to serve, in your current working directory. Open a browser to http://localhost:8080 to see the “website”.
This requires netcat, which you can install with Scoop by running scoop install netcat, or download from Jon Craton here.
The -w1 option makes netcat close the connection after 1 second, which seems necessary for the Windows version of netcat. Unlike the Unix version, it doesn’t automatically close the connection when it reaches the end of the piped input. So unfortunately this is a very slow web server, unless someone knows how to fix this?
For kicks, here’s how to serve a “dynamic website” that reports the current time:

while(1) { "The time is $([datetime]::now)" | nc -w1 -l -p 8080 }
Try hitting refresh in your browser a few times to confirm that this is really working.

And here’s a dynamic REST API that returns the current time in JSON

while(1) { [datetime]::now | convertto-json | nc -w1 -l -p 8080 }

Inspired by Web server in one line of bash

Cowsay in Powershell

Tue, 23 Aug 2022 13:14:40 -1200

I’ve been working on a command-line installer for Windows called Scoop, and I wanted to have some interesting programs to demo it with. Cowsay seemed like an obvious choice.

------------
< Try Scoop! >

\ ^{__^}
\ (oo)_______
(__)\ )\/\
||----w |
|| ||

So I wrote Cowsay in Powershell, trying to follow the functionality of the original Perl version as closely as I could. Afterwards I found that John Kane had already done a PS port—so I’m not the only one who considers this an essential program for the Windows command-line.
There are some benefits to using my version though—it supports (or at least tolerates) the same parameters as the original, so you can use cowthink, change the eyes, pipe your message from another program or specify one of 46 built-in cowfiles (or even use your own).

$ "What powers hell?" | cowthink -f daemon

( What powers hell? )

o , ,
o /( )o \ \___ / | /- _-/ '
(/\/ \ \ /\
/ / | \ O O ) / |-^--'`< '
(.) _ ) /
`.//-----' /
<----. __ / __ \
<----|==O)))) ) /====
<----' --'.,' \
| |
\ /
___( ( / ____
,' ,-----' | \
`--{__________) \/

If you’d like to try it out, you can install Scoop and then run:

$ scoop install cowsay

Figlet in Go

Wed, 10 Aug 2022 22:19:29 -1200

I’ve just finished porting Figlet to the Go programming language. Figlet is a program originally written in 1991 that prints out large ASCII-art letters from the plain text you provide, e.g:

, _ _
/| | | | | | |
|| _ | | | | _ |
| ||/ |/ |/ / _|
| |/|/|/|/__/ o

As with porting Cowsay to Powershell, I mainly did this so I’d have interesting programs to demo Scoop with. If you’re on Windows and you have Scoop installed, you only need to type “scoop install figlet” and you can start playing around.
I did try getting the full C version to build and run on Windows under MSYS, but only got as far a bunch of gibberish being printed. I was way out of my depth, so I decided to port the C code to Go instead.
There were a couple of benefits to using Go. The first being that I could learn a bit about Go, which I really enjoyed. The second is that it should be cross-platform.