main: add short help text

We have accumulated so many options over time that they
no longer fit on the screen.

Display only a useful subset of options to the user unless
they pass "-hh".

3 files changed, 63 insertions, 19 deletions

diff --git a/cli_args.go b/cli_args.go
index be6d688..eb844e1 100644
--- a/cli_args.go
+++ b/cli_args.go
@@ -20,7 +20,7 @@ type argContainer struct {
 	debug, init, zerokey, fusedebug, openssl, passwd, fg, version,
 	plaintextnames, quiet, nosyslog, wpanic,
 	longnames, allow_other, ro, reverse, aessiv, nonempty, raw64,
-	noprealloc, speed, hkdf, serialize_reads, forcedecode bool
+	noprealloc, speed, hkdf, serialize_reads, forcedecode, hh bool
 	masterkey, mountpoint, cipherdir, cpuprofile, extpass,
 	memprofile, ko, passfile, ctlsock, fsname string
 	// Configuration file name override
@@ -94,7 +94,7 @@ func parseCliOpts() (args argContainer) {
 	var opensslAuto string
 
 	flagSet = flag.NewFlagSet(tlog.ProgramName, flag.ContinueOnError)
-	flagSet.Usage = usageText
+	flagSet.Usage = helpShort
 	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")
@@ -125,6 +125,7 @@ func parseCliOpts() (args argContainer) {
 	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."+
 		" Requires gocryptfs to be compiled with openssl support and implies -openssl true")
+	flagSet.BoolVar(&args.hh, "hh", false, "Show this long help text")
 	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")
@@ -145,7 +146,7 @@ func parseCliOpts() (args argContainer) {
 	flagSet.BoolVar(&dummyBool, "nosuid", false, ignoreText)
 	flagSet.BoolVar(&dummyBool, "nodev", false, ignoreText)
 	var dummyString string
-	flagSet.StringVar(&dummyString, "o", "", "For compatibility, all options can be also passed as a comma-separated list to -o.")
+	flagSet.StringVar(&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 {
diff --git a/help.go b/help.go
new file mode 100644
index 0000000..378c380
--- /dev/null
+++ b/help.go
@@ -0,0 +1,53 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/rfjakob/gocryptfs/internal/tlog"
+)
+
+const tUsage = "" +
+	"Usage: " + tlog.ProgramName + " -init|-passwd [OPTIONS] CIPHERDIR\n" +
+	"  or   " + tlog.ProgramName + " [OPTIONS] CIPHERDIR MOUNTPOINT\n"
+
+// helpShort is what gets displayed when passed "-h" or on syntax error.
+func helpShort() {
+	printVersion()
+	fmt.Printf("\n")
+	fmt.Printf(tUsage)
+	fmt.Printf(`
+Common Options (use -hh to show all):
+  -aessiv            Use AES-SIV encryption (with -init)
+  -allow_other       Allow other users to access the mount
+  -config            Custom path to config file
+  -ctlsock           Create control socket at location
+  -extpass           Call external program to prompt for the password
+  -fg                Stay in the foreground
+  -fusedebug         Debug FUSE calls
+  -h, -help          This short help text
+  -hh                Long help text with all options
+  -init              Initialize encrypted directory
+  -masterkey         Mount with explicit master key instead of password
+  -nonempty          Allow mounting over non-empty directory
+  -nosyslog          Do not redirect log messages to syslog
+  -passfile          Read password from file
+  -passwd            Change password
+  -plaintextnames    Do not encrypt file names (with -init)
+  -q, -quiet         Silence informational messages
+  -reverse           Enable reverse mode
+  -ro                Mount read-only
+  -speed             Run crypto speed test
+  -version           Print version information
+  --                 Stop option parsing
+`)
+}
+
+// helpLong gets only displayed on "-hh"
+func helpLong() {
+	printVersion()
+	fmt.Printf("\n")
+	fmt.Printf(tUsage)
+	fmt.Printf("\nOptions:\n")
+	flagSet.PrintDefaults()
+	fmt.Printf("  --\n    	Stop option parsing\n")
+}
diff --git a/main.go b/main.go
index 77d25f4..bc2ca12 100644
--- a/main.go
+++ b/main.go
@@ -31,21 +31,6 @@ var BuildTime = "0"
 // raceDetector is set to true by race.go if we are compiled with "go build -race"
 var raceDetector bool
 
-func usageText() {
-	printVersion()
-	fmt.Printf(`
-Usage: %s -init|-passwd [OPTIONS] CIPHERDIR
-  or   %s [OPTIONS] CIPHERDIR MOUNTPOINT [-o COMMA-SEPARATED-OPTIONS]
-
-Options:
-`, tlog.ProgramName, tlog.ProgramName)
-
-	flagSet.PrintDefaults()
-	fmt.Print(`  --
-    	Stop option parsing
-`)
-}
-
 // loadConfig loads the config file "args.config", prompting the user for the password
 func loadConfig(args *argContainer) (masterkey []byte, confFile *configfile.ConfFile, err error) {
 	// Check if the file can be opened at all before prompting for a password
@@ -145,6 +130,11 @@ func main() {
 		printVersion()
 		os.Exit(0)
 	}
+	// "-hh"
+	if args.hh {
+		helpLong()
+		os.Exit(0)
+	}
 	// "-speed"
 	if args.speed {
 		speed.Run()
@@ -163,7 +153,7 @@ func main() {
 			os.Exit(exitcodes.CipherDir)
 		}
 	} else {
-		usageText()
+		helpShort()
 		os.Exit(exitcodes.Usage)
 	}
 	// "-q"