Add parts.

cmd/parts/README

@@ -0,0 +1,9 @@
+parts: simple parts database for electronic components
+
+Usage:  parts [id] -- query the database for a part
+	parts [-c class] [id] [description] -- store a part in the database
+
+	Options:
+		-f path		Path to parts database (default is
+				/home/kyle/.parts.json).
+

cmd/parts/main.go

@@ -0,0 +1,142 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/kisom/goutils/die"
+)
+
+const dbVersion = "1"
+
+var dbFile = filepath.Join(os.Getenv("HOME"), ".parts.json")
+var partsDB = &database{Version: dbVersion}
+
+type part struct {
+	Name        string `json:"name"`
+	Description string `json:"description"`
+	Class       string `json:"class,omitempty"`
+}
+
+func (p part) String() string {
+	return fmt.Sprintf("%s: %s", p.Name, p.Description)
+}
+
+type database struct {
+	Version    string          `json:"version"`
+	LastUpdate int64           `json:"json"`
+	Parts      map[string]part `json:"parts"`
+}
+
+func help(w io.Writer) {
+	fmt.Fprintf(w, `Usage:  parts [id] -- query the database for a part
+	parts [-c class] [id] [description] -- store a part in the database
+
+	Options:
+		-f path		Path to parts database (default is
+				%s).
+          
+`, dbFile)
+}
+
+func loadDatabase() {
+	data, err := ioutil.ReadFile(dbFile)
+	if err != nil && os.IsNotExist(err) {
+		partsDB = &database{
+			Version: dbVersion,
+			Parts:   map[string]part{},
+		}
+		return
+	}
+	die.If(err)
+
+	err = json.Unmarshal(data, partsDB)
+	die.If(err)
+}
+
+func findPart(partName string) {
+	partName = strings.ToLower(partName)
+	for name, part := range partsDB.Parts {
+		if strings.Contains(strings.ToLower(name), partName) {
+			fmt.Println(part.String())
+		}
+	}
+}
+
+func writeDB() {
+	data, err := json.Marshal(partsDB)
+	die.If(err)
+
+	err = ioutil.WriteFile(dbFile, data, 0644)
+	die.If(err)
+}
+
+func storePart(name, class, description string) {
+	p, exists := partsDB.Parts[name]
+	if exists {
+		fmt.Printf("warning: replacing part %s\n", name)
+		fmt.Printf("\t%s\n", p.String())
+	}
+
+	partsDB.Parts[name] = part{
+		Name:        name,
+		Class:       class,
+		Description: description,
+	}
+
+	writeDB()
+}
+
+func listParts() {
+	parts := make([]string, 0, len(partsDB.Parts))
+	for partName := range partsDB.Parts {
+		parts = append(parts, partName)
+	}
+
+	sort.Strings(parts)
+	for _, partName := range parts {
+		fmt.Println(partsDB.Parts[partName].String())
+	}
+}
+
+func main() {
+	var class string
+	var helpFlag bool
+
+	flag.StringVar(&class, "c", "", "device class")
+	flag.StringVar(&dbFile, "f", dbFile, "`path` to database")
+	flag.BoolVar(&helpFlag, "h", false, "Print a help message.")
+	flag.Parse()
+
+	if helpFlag {
+		help(os.Stdout)
+		return
+	}
+
+	loadDatabase()
+
+	switch flag.NArg() {
+	case 0:
+		help(os.Stdout)
+		return
+	case 1:
+		partName := flag.Arg(0)
+		if partName == "list" {
+			listParts()
+		} else {
+			findPart(flag.Arg(0))
+		}
+		return
+	default:
+		description := strings.Join(flag.Args()[1:], " ")
+		storePart(flag.Arg(0), class, description)
+		return
+	}
+}