goscr

README

goscr

Use go like its a scripting language.

Inspired by https://github.com/bitfield/script, this project aims to make it even easier to write go "scripts". You can for example do things like goscr -c 'script.Stdin().Match("Error").Stdout()' to quickly run a go script. You can also pass a script in as a file as goscr <somescript>, or use goscr in a shebang.

Installation

• You need the go compiler installed, get it from https://go.dev.
• Install / update with go install github.com/witchard/goscr@latest.
• Ensure the bin directory under go env GOPATH is on your PATH.

goscr should work on windows, linux and mac.

Usage

Simply pass a file with your go code in... this code is wrapped up as a function and executed. An error called err is already defined as a named return value - set this to non-nil if you want to exit with an error. Because you are in a function, you can just return to exit your script early.

Under the hood, a .goscr directory in your home drive is used to compile your scripts as full go programs.

A function P is available that behaves like fmt.Println for printing stuff out. A similar function E is also available, but prints to stderr.

A function L is available for processing each line of stdin, it calls a callback function for each line (simple data types are converted automatically), for example:

echo -e "1\n2\n3" | goscr -c "s := 0; err = L(func(i int){s += i}); P(s)"

goscr also works with a shebang (#!), see example.goscr.

To do

This project has only just started... we still need to:

• Support compiling the same program twice - currently bombs out
• Used cached compiled code when the same script is run
• Lock compilation directory so that parallel runs don't interfere with each other
• Support command line options for your scripts
• Support -c for passing code on the command line
• Allow user to hint at what imports are needed
• Support working with #!
• Provide better mechanism for presenting compilation errors back to the user (map line numbers)
• Clean up old compilation directories
• Test on mac and windows
• Support mode where code is run against each line of stdin
• Improve module documentation (and of lines)
• Add more unit tests :-)

Alternatives

• For the ability to run go programs with a shebang: https://github.com/erning/gorun
• Extended go syntax with scripting feel: https://github.com/goplus/gop
• Golang repl and script support: https://github.com/traefik/yaegi