tasks a-s

Task/Read-a-configuration-file/Go/read-a-configuration-file-1.go

@@ -0,0 +1,160 @@
+package config
+
+import (
+	"errors"
+	"io"
+	"fmt"
+	"bytes"
+	"strings"
+	"io/ioutil"
+)
+
+var (
+	ENONE    = errors.New("Requested value does not exist")
+	EBADTYPE = errors.New("Requested type and actual type do not match")
+	EBADVAL  = errors.New("Value and type do not match")
+)
+
+type varError struct {
+	err error
+	n   string
+	t   VarType
+}
+
+func (err *varError) Error() string {
+	return fmt.Sprintf("%v: (%q, %v)", err.err, err.n, err.t)
+}
+
+type VarType int
+
+const (
+	Bool VarType = 1 + iota
+	Array
+	String
+)
+
+func (t VarType) String() string {
+	switch t {
+	case Bool:
+		return "Bool"
+	case Array:
+		return "Array"
+	case String:
+		return "String"
+	}
+
+	panic("Unknown VarType")
+}
+
+type confvar struct {
+	Type VarType
+	Val  interface{}
+}
+
+type Config struct {
+	m map[string]confvar
+}
+
+func Parse(r io.Reader) (c *Config, err error) {
+	c = new(Config)
+	c.m = make(map[string]confvar)
+
+	buf, err := ioutil.ReadAll(r)
+	if err != nil {
+		return
+	}
+
+	lines := bytes.Split(buf, []byte{'\n'})
+
+	for _, line := range lines {
+		line = bytes.TrimSpace(line)
+		if len(line) == 0 {
+			continue
+		}
+		switch line[0] {
+		case '#', ';':
+			continue
+		}
+
+		parts := bytes.SplitN(line, []byte{' '}, 2)
+		nam := string(bytes.ToLower(parts[0]))
+
+		if len(parts) == 1 {
+			c.m[nam] = confvar{Bool, true}
+			continue
+		}
+
+		if strings.Contains(string(parts[1]), ",") {
+			tmpB := bytes.Split(parts[1], []byte{','})
+			for i := range tmpB {
+				tmpB[i] = bytes.TrimSpace(tmpB[i])
+			}
+			tmpS := make([]string, 0, len(tmpB))
+			for i := range tmpB {
+				tmpS = append(tmpS, string(tmpB[i]))
+			}
+
+			c.m[nam] = confvar{Array, tmpS}
+			continue
+		}
+
+		c.m[nam] = confvar{String, string(bytes.TrimSpace(parts[1]))}
+	}
+
+	return
+}
+
+func (c *Config) Bool(name string) (bool, error) {
+	name = strings.ToLower(name)
+
+	if _, ok := c.m[name]; !ok {
+		return false, nil
+	}
+
+	if c.m[name].Type != Bool {
+		return false, &varError{EBADTYPE, name, Bool}
+	}
+
+	v, ok := c.m[name].Val.(bool)
+	if !ok {
+		return false, &varError{EBADVAL, name, Bool}
+	}
+	return v, nil
+}
+
+func (c *Config) Array(name string) ([]string, error) {
+	name = strings.ToLower(name)
+
+	if _, ok := c.m[name]; !ok {
+		return nil, &varError{ENONE, name, Array}
+	}
+
+	if c.m[name].Type != Array {
+		return nil, &varError{EBADTYPE, name, Array}
+	}
+
+	v, ok := c.m[name].Val.([]string)
+	if !ok {
+		return nil, &varError{EBADVAL, name, Array}
+	}
+	return v, nil
+}
+
+func (c *Config) String(name string) (string, error) {
+	name = strings.ToLower(name)
+
+	if _, ok := c.m[name]; !ok {
+		return "", &varError{ENONE, name, String}
+	}
+
+	if c.m[name].Type != String {
+		return "", &varError{EBADTYPE, name, String}
+	}
+
+	v, ok := c.m[name].Val.(string)
+	if !ok {
+		return "", &varError{EBADVAL, name, String}
+	}
+
+	return v, nil
+}

Task/Read-a-configuration-file/Go/read-a-configuration-file-2.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"os"
+	"fmt"
+	"config"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Printf("Usage: %v <configfile>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	file, err := os.Open(os.Args[1])
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	defer file.Close()
+
+	conf, err := config.Parse(file)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	fullname, err := conf.String("fullname")
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	favouritefruit, err := conf.String("favouritefruit")
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	needspeeling, err := conf.Bool("needspeeling")
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	seedsremoved, err := conf.Bool("seedsremoved")
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	otherfamily, err := conf.Array("otherfamily")
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	fmt.Printf("FULLNAME: %q\n", fullname)
+	fmt.Printf("FAVOURITEFRUIT: %q\n", favouritefruit)
+	fmt.Printf("NEEDSPEELING: %q\n", needspeeling)
+	fmt.Printf("SEEDSREMOVED: %q\n", seedsremoved)
+	fmt.Printf("OTHERFAMILY: %q\n", otherfamily)
+}