WIP: switch from go stdlib `flag` to `flaggy`flaggy

7 files changed, 108 insertions, 97 deletions

diff --git a/cli_args.go b/cli_args.go
index ce15448..8dbdcd6 100644
--- a/cli_args.go
+++ b/cli_args.go
@@ -3,10 +3,9 @@ package main
 // Should be initialized before anything else.
 // This import line MUST be in the alphabitcally first source code file of
 // package main!
-import _ "github.com/rfjakob/gocryptfs/internal/ensurefds012"
-
 import (
-	"flag"
+	_ "github.com/rfjakob/gocryptfs/internal/ensurefds012"
+
 	"fmt"
 	"net"
 	"os"
@@ -15,8 +14,9 @@ import (
 	"strings"
 	"time"
 
-	"github.com/hanwen/go-fuse/v2/fuse"
+	"github.com/integrii/flaggy"
 
+	"github.com/hanwen/go-fuse/v2/fuse"
 	"github.com/rfjakob/gocryptfs/internal/configfile"
 	"github.com/rfjakob/gocryptfs/internal/exitcodes"
 	"github.com/rfjakob/gocryptfs/internal/stupidgcm"
@@ -35,9 +35,9 @@ type argContainer struct {
 	masterkey, mountpoint, cipherdir, cpuprofile,
 	memprofile, ko, ctlsock, fsname, force_owner, trace, fido2 string
 	// -extpass, -badname, -passfile can be passed multiple times
-	extpass, badname, passfile multipleStrings
+	extpass, badname, passfile []string
 	// For reverse mode, several ways to specify exclusions. All can be specified multiple times.
-	exclude, excludeWildcard, excludeFrom multipleStrings
+	exclude, excludeWildcard, excludeFrom []string
 	// Configuration file name override
 	config             string
 	notifypid, scryptn int
@@ -71,8 +71,6 @@ func (s *multipleStrings) Empty() bool {
 	return len(s2) == 0
 }
 
-var flagSet *flag.FlagSet
-
 // prefixOArgs transform options passed via "-o foo,bar" into regular options
 // like "-foo -bar" and prefixes them to the command line.
 // Testcases in TestPrefixOArgs().
@@ -126,7 +124,6 @@ func prefixOArgs(osArgs []string) ([]string, error) {
 // parseCliOpts - parse command line options (i.e. arguments that start with "-")
 func parseCliOpts() (args argContainer) {
 	var err error
-	var opensslAuto string
 
 	os.Args, err = prefixOArgs(os.Args)
 	if err != nil {
@@ -134,96 +131,102 @@ func parseCliOpts() (args argContainer) {
 		os.Exit(exitcodes.Usage)
 	}
 
-	flagSet = flag.NewFlagSet(tlog.ProgramName, flag.ContinueOnError)
-	flagSet.Usage = func() {}
-	flagSet.BoolVar(&args.debug, "d", false, "")
-	flagSet.BoolVar(&args.debug, "debug", false, "Enable debug output")
-	flagSet.BoolVar(&args.fusedebug, "fusedebug", false, "Enable fuse library debug output")
-	flagSet.BoolVar(&args.init, "init", false, "Initialize encrypted directory")
-	flagSet.BoolVar(&args.zerokey, "zerokey", false, "Use all-zero dummy master key")
+	flaggy.SetName(tlog.ProgramName)
+	flaggy.DefaultParser.ShowVersionWithVersionFlag = false
+
+	flaggy.AddPositionalValue(&args.cipherdir, "CIPHERDIR", 1, false, "ciphertext directory")
+	flaggy.AddPositionalValue(&args.mountpoint, "MOUNTPOINT", 2, false, "mountpoint")
+
+	flaggy.Bool(&args.debug, "d", "", "")
+	flaggy.Bool(&args.debug, "debug", "", "Enable debug output")
+	flaggy.Bool(&args.fusedebug, "fusedebug", "", "Enable fuse library debug output")
+	flaggy.Bool(&args.init, "init", "", "Initialize encrypted directory")
+	flaggy.Bool(&args.zerokey, "zerokey", "", "Use all-zero dummy master key")
 	// Tri-state true/false/auto
-	flagSet.StringVar(&opensslAuto, "openssl", "auto", "Use OpenSSL instead of built-in Go crypto")
-	flagSet.BoolVar(&args.passwd, "passwd", false, "Change password")
-	flagSet.BoolVar(&args.fg, "f", false, "")
-	flagSet.BoolVar(&args.fg, "fg", false, "Stay in the foreground")
-	flagSet.BoolVar(&args.version, "version", false, "Print version and exit")
-	flagSet.BoolVar(&args.plaintextnames, "plaintextnames", false, "Do not encrypt file names")
-	flagSet.BoolVar(&args.quiet, "q", false, "")
-	flagSet.BoolVar(&args.quiet, "quiet", false, "Quiet - silence informational messages")
-	flagSet.BoolVar(&args.nosyslog, "nosyslog", false, "Do not redirect output to syslog when running in the background")
-	flagSet.BoolVar(&args.wpanic, "wpanic", false, "When encountering a warning, panic and exit immediately")
-	flagSet.BoolVar(&args.longnames, "longnames", true, "Store names longer than 176 bytes in extra files")
-	flagSet.BoolVar(&args.allow_other, "allow_other", false, "Allow other users to access the filesystem. "+
+	opensslAuto := "auto"
+	flaggy.String(&opensslAuto, "openssl", "", "Use OpenSSL instead of built-in Go crypto")
+	flaggy.Bool(&args.passwd, "passwd", "", "Change password")
+	flaggy.Bool(&args.fg, "f", "", "")
+	flaggy.Bool(&args.fg, "fg", "", "Stay in the foreground")
+	flaggy.Bool(&args.version, "version", "", "Print version and exit")
+	flaggy.Bool(&args.plaintextnames, "plaintextnames", "", "Do not encrypt file names")
+	flaggy.Bool(&args.quiet, "q", "", "")
+	flaggy.Bool(&args.quiet, "quiet", "", "Quiet - silence informational messages")
+	flaggy.Bool(&args.nosyslog, "nosyslog", "", "Do not redirect output to syslog when running in the background")
+	flaggy.Bool(&args.wpanic, "wpanic", "", "When encountering a warning, panic and exit immediately")
+	args.longnames = true
+	flaggy.Bool(&args.longnames, "longnames", "", "Store names longer than 176 bytes in extra files")
+	flaggy.Bool(&args.allow_other, "allow_other", "", "Allow other users to access the filesystem. "+
 		"Only works if user_allow_other is set in /etc/fuse.conf.")
-	flagSet.BoolVar(&args.reverse, "reverse", false, "Reverse mode")
-	flagSet.BoolVar(&args.aessiv, "aessiv", false, "AES-SIV encryption")
-	flagSet.BoolVar(&args.nonempty, "nonempty", false, "Allow mounting over non-empty directories")
-	flagSet.BoolVar(&args.raw64, "raw64", true, "Use unpadded base64 for file names")
-	flagSet.BoolVar(&args.noprealloc, "noprealloc", false, "Disable preallocation before writing")
-	flagSet.BoolVar(&args.speed, "speed", false, "Run crypto speed test")
-	flagSet.BoolVar(&args.hkdf, "hkdf", true, "Use HKDF as an additional key derivation step")
-	flagSet.BoolVar(&args.serialize_reads, "serialize_reads", false, "Try to serialize read operations")
-	flagSet.BoolVar(&args.forcedecode, "forcedecode", false, "Force decode of files even if integrity check fails."+
+	flaggy.Bool(&args.reverse, "reverse", "", "Reverse mode")
+	flaggy.Bool(&args.aessiv, "aessiv", "", "AES-SIV encryption")
+	flaggy.Bool(&args.nonempty, "nonempty", "", "Allow mounting over non-empty directories")
+	args.raw64 = true
+	flaggy.Bool(&args.raw64, "raw64", "", "Use unpadded base64 for file names")
+	flaggy.Bool(&args.noprealloc, "noprealloc", "", "Disable preallocation before writing")
+	flaggy.Bool(&args.speed, "speed", "", "Run crypto speed test")
+	args.hkdf = true
+	flaggy.Bool(&args.hkdf, "hkdf", "", "Use HKDF as an additional key derivation step")
+	flaggy.Bool(&args.serialize_reads, "serialize_reads", "", "Try to serialize read operations")
+	flaggy.Bool(&args.forcedecode, "forcedecode", "", "Force decode of files even if integrity check fails."+
 		" Requires gocryptfs to be compiled with openssl support and implies -openssl true")
-	flagSet.BoolVar(&args.hh, "hh", false, "Show this long help text")
-	flagSet.BoolVar(&args.info, "info", false, "Display information about CIPHERDIR")
-	flagSet.BoolVar(&args.sharedstorage, "sharedstorage", false, "Make concurrent access to a shared CIPHERDIR safer")
-	flagSet.BoolVar(&args.devrandom, "devrandom", false, "Use /dev/random for generating master key")
-	flagSet.BoolVar(&args.fsck, "fsck", false, "Run a filesystem check on CIPHERDIR")
+	flaggy.Bool(&args.hh, "hh", "", "Show this long help text")
+	flaggy.Bool(&args.info, "info", "", "Display information about CIPHERDIR")
+	flaggy.Bool(&args.sharedstorage, "sharedstorage", "", "Make concurrent access to a shared CIPHERDIR safer")
+	flaggy.Bool(&args.devrandom, "devrandom", "", "Use /dev/random for generating master key")
+	flaggy.Bool(&args.fsck, "fsck", "", "Run a filesystem check on CIPHERDIR")
 
 	// Mount options with opposites
-	flagSet.BoolVar(&args.dev, "dev", false, "Allow device files")
-	flagSet.BoolVar(&args.nodev, "nodev", false, "Deny device files")
-	flagSet.BoolVar(&args.suid, "suid", false, "Allow suid binaries")
-	flagSet.BoolVar(&args.nosuid, "nosuid", false, "Deny suid binaries")
-	flagSet.BoolVar(&args.exec, "exec", false, "Allow executables")
-	flagSet.BoolVar(&args.noexec, "noexec", false, "Deny executables")
-	flagSet.BoolVar(&args.rw, "rw", false, "Mount the filesystem read-write")
-	flagSet.BoolVar(&args.ro, "ro", false, "Mount the filesystem read-only")
-	flagSet.BoolVar(&args.kernel_cache, "kernel_cache", false, "Enable the FUSE kernel_cache option")
-	flagSet.BoolVar(&args.acl, "acl", false, "Enforce ACLs")
+	flaggy.Bool(&args.dev, "dev", "", "Allow device files")
+	flaggy.Bool(&args.nodev, "nodev", "", "Deny device files")
+	flaggy.Bool(&args.suid, "suid", "", "Allow suid binaries")
+	flaggy.Bool(&args.nosuid, "nosuid", "", "Deny suid binaries")
+	flaggy.Bool(&args.exec, "exec", "", "Allow executables")
+	flaggy.Bool(&args.noexec, "noexec", "", "Deny executables")
+	flaggy.Bool(&args.rw, "rw", "", "Mount the filesystem read-write")
+	flaggy.Bool(&args.ro, "ro", "", "Mount the filesystem read-only")
+	flaggy.Bool(&args.kernel_cache, "kernel_cache", "", "Enable the FUSE kernel_cache option")
+	flaggy.Bool(&args.acl, "acl", "", "Enforce ACLs")
 
-	flagSet.StringVar(&args.masterkey, "masterkey", "", "Mount with explicit master key")
-	flagSet.StringVar(&args.cpuprofile, "cpuprofile", "", "Write cpu profile to specified file")
-	flagSet.StringVar(&args.memprofile, "memprofile", "", "Write memory profile to specified file")
-	flagSet.StringVar(&args.config, "config", "", "Use specified config file instead of CIPHERDIR/gocryptfs.conf")
-	flagSet.StringVar(&args.ko, "ko", "", "Pass additional options directly to the kernel, comma-separated list")
-	flagSet.StringVar(&args.ctlsock, "ctlsock", "", "Create control socket at specified path")
-	flagSet.StringVar(&args.fsname, "fsname", "", "Override the filesystem name")
-	flagSet.StringVar(&args.force_owner, "force_owner", "", "uid:gid pair to coerce ownership")
-	flagSet.StringVar(&args.trace, "trace", "", "Write execution trace to file")
-	flagSet.StringVar(&args.fido2, "fido2", "", "Protect the masterkey using a FIDO2 token instead of a password")
+	flaggy.String(&args.masterkey, "masterkey", "", "Mount with explicit master key")
+	flaggy.String(&args.cpuprofile, "cpuprofile", "", "Write cpu profile to specified file")
+	flaggy.String(&args.memprofile, "memprofile", "", "Write memory profile to specified file")
+	flaggy.String(&args.config, "config", "", "Use specified config file instead of CIPHERDIR/gocryptfs.conf")
+	flaggy.String(&args.ko, "ko", "", "Pass additional options directly to the kernel, comma-separated list")
+	flaggy.String(&args.ctlsock, "ctlsock", "", "Create control socket at specified path")
+	flaggy.String(&args.fsname, "fsname", "", "Override the filesystem name")
+	flaggy.String(&args.force_owner, "force_owner", "", "uid:gid pair to coerce ownership")
+	flaggy.String(&args.trace, "trace", "", "Write execution trace to file")
+	flaggy.String(&args.fido2, "fido2", "", "Protect the masterkey using a FIDO2 token instead of a password")
 
 	// Exclusion options
-	flagSet.Var(&args.exclude, "e", "Alias for -exclude")
-	flagSet.Var(&args.exclude, "exclude", "Exclude relative path from reverse view")
-	flagSet.Var(&args.excludeWildcard, "ew", "Alias for -exclude-wildcard")
-	flagSet.Var(&args.excludeWildcard, "exclude-wildcard", "Exclude path from reverse view, supporting wildcards")
-	flagSet.Var(&args.excludeFrom, "exclude-from", "File from which to read exclusion patterns (with -exclude-wildcard syntax)")
+	flaggy.StringSlice(&args.exclude, "e", "exclude", "Exclude relative path from reverse view")
+	flaggy.StringSlice(&args.excludeWildcard, "ew", "exclude-wildcard", "Exclude path from reverse view, supporting wildcards")
+	flaggy.StringSlice(&args.excludeFrom, "exclude-from", "", "File from which to read exclusion patterns (with -exclude-wildcard syntax)")
 
 	// multipleStrings options ([]string)
-	flagSet.Var(&args.extpass, "extpass", "Use external program for the password prompt")
-	flagSet.Var(&args.badname, "badname", "Glob pattern invalid file names that should be shown")
-	flagSet.Var(&args.passfile, "passfile", "Read password from file")
+	flaggy.StringSlice(&args.extpass, "extpass", "", "Use external program for the password prompt")
+	flaggy.StringSlice(&args.badname, "badname", "", "Glob pattern invalid file names that should be shown")
+	flaggy.StringSlice(&args.passfile, "passfile", "", "Read password from file")
 
-	flagSet.IntVar(&args.notifypid, "notifypid", 0, "Send USR1 to the specified process after "+
+	flaggy.Int(&args.notifypid, "notifypid", "", "Send USR1 to the specified process after "+
 		"successful mount - used internally for daemonization")
 	const scryptn = "scryptn"
-	flagSet.IntVar(&args.scryptn, scryptn, configfile.ScryptDefaultLogN, "scrypt cost parameter logN. Possible values: 10-28. "+
+	args.scryptn = configfile.ScryptDefaultLogN
+	flaggy.Int(&args.scryptn, scryptn, "", "scrypt cost parameter logN. Possible values: 10-28. "+
 		"A lower value speeds up mounting and reduces its memory needs, but makes the password susceptible to brute-force attacks")
 
-	flagSet.DurationVar(&args.idle, "i", 0, "Alias for -idle")
-	flagSet.DurationVar(&args.idle, "idle", 0, "Auto-unmount after specified idle duration (ignored in reverse mode). "+
+	flaggy.Duration(&args.idle, "i", "idle", "Auto-unmount after specified idle duration (ignored in reverse mode). "+
 		"Durations are specified like \"500s\" or \"2h45m\". 0 means stay mounted indefinitely.")
 
 	var nofail bool
-	flagSet.BoolVar(&nofail, "nofail", false, "Ignored for /etc/fstab compatibility")
+	flaggy.Bool(&nofail, "nofail", "", "Ignored for /etc/fstab compatibility")
 
 	var dummyString string
-	flagSet.StringVar(&dummyString, "o", "", "For compatibility with mount(1), options can be also passed as a comma-separated list to -o on the end.")
+	flaggy.String(&dummyString, "o", "", "For compatibility with mount(1), options can be also passed as a comma-separated list to -o on the end.")
 	// Actual parsing
-	err = flagSet.Parse(os.Args[1:])
-	if err == flag.ErrHelp {
+	err = flaggy.DefaultParser.Parse()
+	if err != nil {
 		helpShort()
 		os.Exit(0)
 	}
@@ -232,7 +235,7 @@ func parseCliOpts() (args argContainer) {
 		os.Exit(exitcodes.Usage)
 	}
 	// We want to know if -scryptn was passed explicitly
-	if isFlagPassed(flagSet, scryptn) {
+	if false /* TODO isFlagPassed(flaggy, scryptn)*/ {
 		args._explicitScryptn = true
 	}
 	// "-openssl" needs some post-processing
@@ -271,7 +274,7 @@ func parseCliOpts() (args argContainer) {
 		args.allow_other = false
 		args.ko = "noexec"
 	}
-	if !args.extpass.Empty() && len(args.passfile) != 0 {
+	if len(args.extpass) > 0 && len(args.passfile) != 0 {
 		tlog.Fatal.Printf("The options -extpass and -passfile cannot be used at the same time")
 		os.Exit(exitcodes.Usage)
 	}
@@ -279,11 +282,11 @@ func parseCliOpts() (args argContainer) {
 		tlog.Fatal.Printf("The options -passfile and -masterkey cannot be used at the same time")
 		os.Exit(exitcodes.Usage)
 	}
-	if !args.extpass.Empty() && args.masterkey != "" {
+	if len(args.extpass) > 0 && args.masterkey != "" {
 		tlog.Fatal.Printf("The options -extpass and -masterkey cannot be used at the same time")
 		os.Exit(exitcodes.Usage)
 	}
-	if !args.extpass.Empty() && args.fido2 != "" {
+	if len(args.extpass) > 0 && args.fido2 != "" {
 		tlog.Fatal.Printf("The options -extpass and -fido2 cannot be used at the same time")
 		os.Exit(exitcodes.Usage)
 	}
@@ -331,12 +334,14 @@ func countOpFlags(args *argContainer) int {
 
 // isFlagPassed finds out if the flag was explictely passed on the command line.
 // https://stackoverflow.com/a/54747682/1380267
-func isFlagPassed(flagSet *flag.FlagSet, name string) bool {
+/* TODO
+func isFlagPassed(flaggy *flag.flaggy, name string) bool {
 	found := false
-	flagSet.Visit(func(f *flag.Flag) {
+	flaggy.Visit(func(f *flag.Flag) {
 		if f.Name == name {
 			found = true
 		}
 	})
 	return found
 }
+*/
diff --git a/go.mod b/go.mod
index f23fad4..76fff65 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.16
 
 require (
 	github.com/hanwen/go-fuse/v2 v2.1.1-0.20210802120645-15a8bb029a4e
+	github.com/integrii/flaggy v1.4.4 // indirect
 	github.com/jacobsa/crypto v0.0.0-20190317225127-9f44e2d11115
 	github.com/jacobsa/oglematchers v0.0.0-20150720000706-141901ea67cd // indirect
 	github.com/jacobsa/oglemock v0.0.0-20150831005832-e94d794d06ff // indirect
@@ -12,6 +13,7 @@ require (
 	github.com/pkg/xattr v0.4.1
 	github.com/rfjakob/eme v1.1.1
 	github.com/sabhiram/go-gitignore v0.0.0-20180611051255-d3107576ba94
+	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/stretchr/testify v1.5.1 // indirect
 	golang.org/x/crypto v0.0.0-20200429183012-4b2356b1ed79
 	golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e // indirect
diff --git a/go.sum b/go.sum
index ef4fe81..3f283ed 100644
--- a/go.sum
+++ b/go.sum
@@ -2,6 +2,8 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/hanwen/go-fuse/v2 v2.1.1-0.20210802120645-15a8bb029a4e h1:mykFj7/XZmUTy/rRWaqbqHJEFU+dXfLmuigEWTlgECE=
 github.com/hanwen/go-fuse/v2 v2.1.1-0.20210802120645-15a8bb029a4e/go.mod h1:B1nGE/6RBFyBRC1RRnf23UpwCdyJ31eukw34oAKukAc=
+github.com/integrii/flaggy v1.4.4 h1:8fGyiC14o0kxhTqm2VBoN19fDKPZsKipP7yggreTMDc=
+github.com/integrii/flaggy v1.4.4/go.mod h1:tnTxHeTJbah0gQ6/K0RW0J7fMUBk9MCF5blhm43LNpI=
 github.com/jacobsa/crypto v0.0.0-20190317225127-9f44e2d11115 h1:YuDUUFNM21CAbyPOpOP8BicaTD/0klJEKt5p8yuw+uY=
 github.com/jacobsa/crypto v0.0.0-20190317225127-9f44e2d11115/go.mod h1:LadVJg0XuawGk+8L1rYnIED8451UyNxEMdTWCEt5kmU=
 github.com/jacobsa/oglematchers v0.0.0-20150720000706-141901ea67cd h1:9GCSedGjMcLZCrusBZuo4tyKLpKUPenUUqi34AkuFmA=
@@ -22,6 +24,8 @@ github.com/rfjakob/eme v1.1.1 h1:t+CgvcOn+eDvj2xdglxsSnkgg8LM8jwdxnV7OnsrTn0=
 github.com/rfjakob/eme v1.1.1/go.mod h1:U2bmx0hDj8EyDdcxmD5t3XHDnBFnyNNc22n1R4008eM=
 github.com/sabhiram/go-gitignore v0.0.0-20180611051255-d3107576ba94 h1:G04eS0JkAIVZfaJLjla9dNxkJCPiKIGZlw9AfOhzOD0=
 github.com/sabhiram/go-gitignore v0.0.0-20180611051255-d3107576ba94/go.mod h1:b18R55ulyQ/h3RaWyloPyER7fWQVZvimKKhnI5OfrJQ=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
diff --git a/help.go b/help.go
index 5cd35ac..00c318c 100644
--- a/help.go
+++ b/help.go
@@ -3,6 +3,8 @@ package main
 import (
 	"fmt"
 
+	"github.com/integrii/flaggy"
+
 	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 
@@ -51,6 +53,6 @@ func helpLong() {
 	fmt.Printf("\n")
 	fmt.Printf(tUsage)
 	fmt.Printf("\nOptions:\n")
-	flagSet.PrintDefaults()
+	flaggy.ShowHelp("")
 	fmt.Printf("  --\n    	Stop option parsing\n")
 }
diff --git a/init_dir.go b/init_dir.go
index 68268a0..54a44e4 100644
--- a/init_dir.go
+++ b/init_dir.go
@@ -69,7 +69,7 @@ func initDir(args *argContainer) {
 		}
 	}
 	// Choose password for config file
-	if args.extpass.Empty() && args.fido2 == "" {
+	if len(args.extpass) == 0 && args.fido2 == "" {
 		tlog.Info.Printf("Choose a password for protecting your files.")
 	}
 	{
diff --git a/main.go b/main.go
index 9bd0c78..28ac010 100644
--- a/main.go
+++ b/main.go
@@ -169,7 +169,7 @@ func main() {
 	args := parseCliOpts()
 	// Fork a child into the background if "-fg" is not set AND we are mounting
 	// a filesystem. The child will do all the work.
-	if !args.fg && flagSet.NArg() == 2 {
+	if !args.fg && args.cipherdir != "" && args.mountpoint != "" {
 		ret := forkChild()
 		os.Exit(ret)
 	}
@@ -200,8 +200,8 @@ func main() {
 		tlog.Debug.Printf("Panicking on warnings")
 	}
 	// Every operation below requires CIPHERDIR. Exit if we don't have it.
-	if flagSet.NArg() == 0 {
-		if flagSet.NFlag() == 0 {
+	if args.cipherdir == "" {
+		if len(os.Args[1:]) == 0 {
 			// Naked call to "gocryptfs". Just print the help text.
 			helpShort()
 		} else {
@@ -212,7 +212,7 @@ func main() {
 		os.Exit(exitcodes.Usage)
 	}
 	// Check that CIPHERDIR exists
-	args.cipherdir, _ = filepath.Abs(flagSet.Arg(0))
+	args.cipherdir, _ = filepath.Abs(args.cipherdir)
 	err = isDir(args.cipherdir)
 	if err != nil {
 		tlog.Fatal.Printf("Invalid cipherdir: %v", err)
@@ -287,10 +287,9 @@ func main() {
 	nOps := countOpFlags(&args)
 	if nOps == 0 {
 		// Default operation: mount.
-		if flagSet.NArg() != 2 {
+		if args.cipherdir == "" || args.mountpoint == "" {
 			prettyArgs := prettyArgs()
-			tlog.Info.Printf("Wrong number of arguments (have %d, want 2). You passed: %s",
-				flagSet.NArg(), prettyArgs)
+			tlog.Info.Printf("Wrong number of arguments. You passed: %s", prettyArgs)
 			tlog.Fatal.Printf("Usage: %s [OPTIONS] CIPHERDIR MOUNTPOINT [-o COMMA-SEPARATED-OPTIONS]", tlog.ProgramName)
 			os.Exit(exitcodes.Usage)
 		}
@@ -302,9 +301,8 @@ func main() {
 		tlog.Fatal.Printf("At most one of -info, -init, -passwd, -fsck is allowed")
 		os.Exit(exitcodes.Usage)
 	}
-	if flagSet.NArg() != 1 {
-		tlog.Fatal.Printf("The options -info, -init, -passwd, -fsck take exactly one argument, %d given",
-			flagSet.NArg())
+	if args.cipherdir == "" || args.mountpoint != "" {
+		tlog.Fatal.Printf("The options -info, -init, -passwd, -fsck take exactly one argument")
 		os.Exit(exitcodes.Usage)
 	}
 	// "-info"
diff --git a/mount.go b/mount.go
index ab4ad81..bc752ac 100644
--- a/mount.go
+++ b/mount.go
@@ -45,7 +45,7 @@ type AfterUnmounter interface {
 func doMount(args *argContainer) {
 	// Check mountpoint
 	var err error
-	args.mountpoint, err = filepath.Abs(flagSet.Arg(1))
+	args.mountpoint, err = filepath.Abs(args.mountpoint)
 	if err != nil {
 		tlog.Fatal.Printf("Invalid mountpoint: %v", err)
 		os.Exit(exitcodes.MountPoint)