Serhii Mudryk msoap

Story: Writing Scripts with Go

This is a story about how I tried to use Go for scripting. In this story, I’ll discuss the need for a Go script, how we would expect it to behave and the possible implementations; During the discussion I’ll deep dive to scripts, shells, and shebangs. Finally, we’ll discuss solutions that will make Go scripts work.

Why Go is good for scripting?

While python and bash are popular scripting languages, C, C++ and Java are not used for scripts at all, and some languages are somewhere in between.

	package main

	import (
	"fmt"
	"image"
	"image/color"
	"image/gif"
	"math"
	"os"
	)

	#!/usr/bin/awk -f

	# This program is a copy of guff, a plot device. https://github.com/silentbicycle/guff
	# My copy here is written in awk instead of C, has no compelling benefit.
	# Public domain. @thingskatedid

	# Run as awk -v x=xyz ... or env variables for stuff?
	# Assumptions: the data is evenly spaced along the x-axis

	# TODO: moving average

	name old time/op new time/op delta
	BinaryTree17 5.44s ± 2% 3.27s ± 2% -39.90% (p=0.000 n=20+19)
	Fannkuch11 4.95s ± 2% 2.68s ± 2% -45.87% (p=0.000 n=20+20)
	FmtFprintfEmpty 142ns ± 2% 49ns ± 3% -65.39% (p=0.000 n=20+18)
	FmtFprintfFloat 765ns ± 2% 260ns ± 2% -66.02% (p=0.000 n=20+20)
	FmtFprintfInt 341ns ± 2% 95ns ± 2% -72.08% (p=0.000 n=19+20)
	FmtFprintfIntInt 554ns ± 2% 150ns ± 1% -72.95% (p=0.000 n=20+19)
	FmtFprintfPrefixedInt 497ns ± 3% 178ns ± 3% -64.12% (p=0.000 n=20+20)
	FmtFprintfString 466ns ± 2% 86ns ± 3% -81.54% (p=0.000 n=20+20)
	FmtManyArgs 2.23µs ± 2% 0.59µs ± 1% -73.46% (p=0.000 n=20+17)

	# LVDB - LLOOGG Memory DB
	# Copyriht (C) 2009 Salvatore Sanfilippo <[email protected]>
	# All Rights Reserved

	# TODO
	# - cron with cleanup of timedout clients, automatic dump
	# - the dump should use array startsearch to write it line by line
	# and may just use gets to read element by element and load the whole state.
	# - 'help','stopserver','saveandstopserver','save','load','reset','keys' commands.
	# - ttl with milliseconds resolution 'ttl a 1000'. Check ttl in dump!

	package main

	import (
	"context"
	"log"
	"net/http"
	"os"
	"os/signal"
	"time"
	)

	#!/bin/bash
	# Simple script which decode and encode messages based on user github key.
	# Usage:
	# Encrypt:
	# echo "My secret is" \| ./ghcrypt.sh -u ctrlok
	# Decrypt:
	# echo "BASE64SCRET" \| ./ghcrypt.sh -k ~/.ssh/id_rsa


	while getopts "u:k:" opt

	%.hex: %.asm
	avra -fI $<
	rm .eep.hex .obj *.cof

	all: $(patsubst %.asm,%.hex,$(wildcard *.asm))

	upload: ${program}.hex
	avrdude -c arduino -p m328p -P /dev/arduino-uno -b 115200 -U flash:w:$<

	monitor:

	package main

	import (
	"math/rand"
	"testing"
	"time"
	)

	const (
	numItems = 100 // change this to see how number of items affects speed

	package main

	import (
	"log"
	"syscall"
	"unsafe"
	)

	var (
	kernel32 = syscall.NewLazyDLL("kernel32.dll")