fix: use getopt library for argument parsing

fixes #23

Signed-off-by: moson-mo <mo-son@mailbox.org>

go.mod

@@ -31,8 +31,10 @@ require (
 	github.com/gdamore/encoding v1.0.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
 	github.com/mattn/go-runewidth v0.0.14 // indirect
+	github.com/pborman/getopt/v2 v2.1.0
 	github.com/rivo/uniseg v0.4.2 // indirect
 	github.com/stretchr/testify v1.7.1
+	golang.org/x/exp v0.0.0-20221019170559-20944726eadf
 	golang.org/x/sys v0.1.0 // indirect
 	golang.org/x/term v0.1.0 // indirect
 	golang.org/x/text v0.4.0 // indirect

go.sum

@@ -46,6 +46,8 @@ github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9G
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
 github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
+github.com/pborman/getopt/v2 v2.1.0 h1:eNfR+r+dWLdWmV8g5OlpyrTYHkhVNxHBdN2cCrJmOEA=
+github.com/pborman/getopt/v2 v2.1.0/go.mod h1:4NtW75ny4eBw9fO1bhtNdYTlZKYX5/tBLtsOpwKIKd0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rivo/tview v0.0.0-20220916081518-2e69b7385a37 h1:cTzFg1FfTXwXuODi7Doz70hsW+dAye1OBwAFWHCqmww=
@@ -62,6 +64,8 @@ github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMT
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/urfave/cli v1.22.3/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/exp v0.0.0-20221019170559-20944726eadf h1:nFVjjKDgNY37+ZSYCJmtYf7tOlfQswHqplG2eosjOMg=
+golang.org/x/exp v0.0.0-20221019170559-20944726eadf/go.mod h1:cyybsKvd6eL0RnXn6p/Grxp8F5bW7iYuBgsNCOHpMYE=
 golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200301022130-244492dfa37a/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=

internal/args/args.go

@@ -1,10 +1,9 @@
 package args
 
 import (
-	"errors"
 	"strings"
 
-	"github.com/moson-mo/pacseek/internal/util"
+	"github.com/pborman/getopt/v2"
 )
 
 // Flags struct holds our flag options
@@ -15,65 +14,41 @@ type Flags struct {
 	MonochromeMode bool
 	ShowUpdates    bool
 	ShowInstalled  bool
+	Help           bool
 }
 
 // Parse is parsing our arguments and creates a Flags struct from it
-func Parse(args []string) (*Flags, error) {
-	flags := &Flags{}
-	prevFlag := ""
-
-	// set search term to first argument if it's not a flag
-	if len(args) > 0 && !strings.HasPrefix(args[0], "-") {
-		flags.SearchTerm = args[0]
-	}
-
-	for i, flag := range args {
-		// set search term to the last argument if it's not a flag and the previous flag was not a string flag
-		if len(args) == i+1 && !strings.HasPrefix(flag, "-") && !util.SliceContains(stringFlags(), prevFlag) {
-			flags.SearchTerm = flag
+func Parse() Flags {
+	repos := getopt.String('r', "", "Limit searching to a comma separated list of repositories")
+	term := getopt.String('s', "", "Search-term")
+	ascii := getopt.Bool('a', "ASCII mode")
+	mono := getopt.Bool('m', "Monochrome mode")
+	upd := getopt.Bool('u', "Show updates after startup")
+	inst := getopt.Bool('i', "Show installed packages after startup")
+	help := getopt.BoolLong("help", 'h', "Show usage / help")
+	qhelp := getopt.BoolLong("?", '?', "Show usage / help")
+
+	err := getopt.Getopt(nil)
+	if err != nil {
+		return Flags{
+			Help: true,
 		}
-		// if we have a flag
-		if strings.HasPrefix(flag, "-") {
-			flag = strings.ReplaceAll(flag, "-", "") // strip dashes from flag
+	}
 
-			// iterate over characters in flag to allow several options in just one flag, e.g. "-amui"
-			for _, r := range flag {
-				if !util.SliceContains(possibleFlags(), string(r)) {
-					return nil, errors.New("flag not supported: " + flag)
-				}
-				switch r {
-				case 'a':
-					flags.AsciiMode = true
-				case 'm':
-					flags.MonochromeMode = true
-				case 'u':
-					flags.ShowUpdates = true
-				case 'i':
-					flags.ShowInstalled = true
-				case 's':
-					if len(args) <= i+1 {
-						return nil, errors.New("search-term argument is missing")
-					}
-					flags.SearchTerm = args[i+1]
-				case 'r':
-					if len(args) <= i+1 {
-						return nil, errors.New("repositories argument is missing")
-					}
-					flags.Repositories = strings.Split(args[i+1], ",")
-				}
-			}
-		}
-		prevFlag = flag
+	flags := Flags{
+		Repositories:   strings.Split(*repos, ","),
+		SearchTerm:     *term,
+		AsciiMode:      *ascii,
+		MonochromeMode: *mono,
+		ShowUpdates:    *upd,
+		ShowInstalled:  *inst,
 	}
-	flags.SearchTerm = strings.ToLower(flags.SearchTerm)
 
-	return flags, nil
-}
+	flags.Help = *help || *qhelp
 
-func possibleFlags() []string {
-	return []string{"s", "r", "a", "m", "u", "i"}
-}
+	if flags.SearchTerm == "" && len(getopt.Args()) > 0 {
+		flags.SearchTerm = getopt.Args()[0]
+	}
 
-func stringFlags() []string {
-	return []string{"s", "r"}
+	return flags
 }

main.go

@@ -43,11 +43,10 @@ func main() {
 		fmt.Println("pacseek should not be run as root.")
 	}
 
-	f, err := args.Parse(os.Args[1:])
-	if err != nil {
-		fmt.Println(err)
+	f := args.Parse()
+	if f.Help {
 		printHelp()
-		os.Exit(1)
+		os.Exit(0)
 	}
 
 	conf, err := config.Load()
@@ -61,7 +60,7 @@ func main() {
 			printErrorExit("Error loading configuration file", err)
 		}
 	}
-	ps, err := pacseek.New(conf, *f)
+	ps, err := pacseek.New(conf, f)
 	if err != nil {
 		printErrorExit("Error during pacseek initialization", err)
 	}