gobench-1

package bench

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"os"
	"strings"
)

const (
	bufferSize = 100
)

func Find(path, s string) (string, error) {
	if len(s) == 0 {
		return "", errors.New("")
	}

	f, err := os.Open(path)
	if err != nil {
		return "", err
	}
	defer f.Close()

	scanner := bufio.NewScanner(f)

	row := 1
	matches := make([]string, 0)
	for scanner.Scan() {
		line := scanner.Text()

		if err != nil {
			if err == io.EOF {
				break
			}
			return "", err
		}
		colOffset := 0
		for col := strings.Index(line, s); col > -1; col = strings.Index(line[colOffset:], s) {
			matches = append(matches, fmt.Sprintf("%d:%d", row, col+colOffset))
			colOffset += col + 1
		}
		row++
	}
	return strings.Join(matches, ","), nil
}