re2match - command line tool matching re2-like regexes on data read from stdin

main.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"regexp"
)

const usage = "usage: echo TEXT | re2match REGEXP"

func die(v ...interface{}) {
	for _, v := range v {
		fmt.Fprintln(os.Stderr, v)
	}
	os.Exit(1)
}

func main() {
	if len(os.Args) != 2 {
		die(usage)
	}
	if ok, err := regexp.MatchReader(os.Args[1], bufio.NewReader(os.Stdin)); err != nil {
		die(err)
	} else if !ok {
		die()
	}
}