qsh

README

qsh

q shell

INSTALLATION

$ go get github.com/lufia/qsh

Language

Comment

# comment

Variables

Simple declaration.

a=1     # scalar; same as a=(1)
a=(1 2) # array

echo $a
# Output:
# 1 2

if variable name all are capital letter, it handles as environment variables.

RESULT_CODE=1
bash -c 'echo $RESULT_CODE'
# Output: 1

Indirect reference

arch=lib_amd64
lib_amd64=lib64
lib_x86=lib

echo $$arch
# Output:
# lib64

If statement

if { true } {
	echo ok
}
# Output:
# ok

For statement

for i in 1 2 3 {
	echo $i
}
# Output:
# 1
# 2
# 3

Modules

first, write your code in Go.

package main

var SampleModule = map[string]string{
	"hello": "Hello",
}

func Hello(args []string) ([]string, error) {
	a := make([]string, 0, len(args)+1)
	a = append(a, "hello")
	return append(a, args...), nil
}

build it as plugin.

go build -buildmode=plugin sample.go

then load with load stamtement.

load sample # plugin filepath without .so
echo ${hello a ${hello b}}
# Output: hello a hello b

Expression

true && echo true

false || echo false

Redirection

# output
echo hello >out

# append
echo hello >>out

# input
echo hello <in

# pipe
echo hello | wc

TODO

• Basic
  • comments
  • command execution
  • background execution
  • inline execution
  • glob
• Variable
  • assign
  • indexing
  • concat
  • environment
• Redirection
  • read
  • write
  • append
  • error
  • pipe
  • dup
• Statements
  • if
  • if-else
  • for
  • switch
  • load
• Expression
  • &&
  • ||

Advent calendar

• https://blog.zoncoen.net/2015/12/22/cli-toml-processor-with-goyacc/
• https://qiita.com/draftcode/items/c9f2422fca14133c7f6a
• https://dev.classmethod.jp/etc/goyacc-json-generator/