support F-Droid's CSV export in install

Easy enough to do; we just read from stdin when given no arguments, and
convert the CSV fields to the argument string format.

Fixes #30.

README.md

@@ -30,7 +30,7 @@ Install an app:
 	update                Update the index
 	search [<regexp...>]  Search available apps
 	show <appid...>       Show detailed info about an app
-	install <appid...>    Install or upgrade apps
+	install [<appid...>]  Install or upgrade apps
 	uninstall <appid...>  Uninstall an app
 	download <appid...>   Download an app
 	devices               List connected devices

install.go

@@ -4,7 +4,9 @@
 package main
 
 import (
+	"encoding/csv"
 	"fmt"
+	"io"
 	"os"
 
 	"mvdan.cc/fdroidcl/adb"
@@ -12,8 +14,15 @@ import (
 )
 
 var cmdInstall = &Command{
-	UsageLine: "install <appid...>",
+	UsageLine: "install [<appid...>]",
 	Short:     "Install or upgrade apps",
+	Long: `
+Install or upgrade apps. When given no arguments, it reads a comma-separated
+list of apps to install from standard input, like:
+
+	packageName,versionCode,versionName
+	foo.bar,120,1.2.0
+`[1:],
 }
 
 var (
@@ -26,12 +35,8 @@ func init() {
 }
 
 func runInstall(args []string) error {
-	if *installUpdates {
-		if len(args) > 0 {
-			return fmt.Errorf("-u can only be used without arguments")
-		}
-	} else if len(args) < 1 {
-		return fmt.Errorf("no package names given")
+	if *installUpdates && len(args) > 0 {
+		return fmt.Errorf("-u can only be used without arguments")
 	}
 	device, err := oneDevice()
 	if err != nil {
@@ -54,6 +59,29 @@ func runInstall(args []string) error {
 		return downloadAndDo(apps, device)
 	}
 
+	if len(args) == 0 {
+		// The CSV input is as follows:
+		//
+		// packageName,versionCode,versionName
+		// foo.bar,120,1.2.0
+		// ...
+
+		r := csv.NewReader(os.Stdin)
+		r.FieldsPerRecord = 3
+		r.Read()
+		for {
+			record, err := r.Read()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return fmt.Errorf("error parsing CSV: %v", err)
+			}
+			// convert "foo.bar,120" into "foo.bar:120" for findApps
+			args = append(args, record[0]+":"+record[1])
+		}
+	}
+
 	apps, err := findApps(args)
 	if err != nil {
 		return err

main.go

@@ -96,9 +96,12 @@ type Command struct {
 	// The first word in the line is taken to be the command name.
 	UsageLine string
 
-	// Short is the short description.
+	// Short is the short, single-line description.
 	Short string
 
+	// Long is an optional longer version of the Short description.
+	Long string
+
 	Fset flag.FlagSet
 }
 
@@ -113,7 +116,12 @@ func (c *Command) Name() string {
 }
 
 func (c *Command) usage() {
-	fmt.Fprintf(os.Stderr, "usage: %s %s\n", cmdName, c.UsageLine)
+	fmt.Fprintf(os.Stderr, "usage: %s %s\n\n", cmdName, c.UsageLine)
+	if c.Long == "" {
+		fmt.Fprintf(os.Stderr, "%s.\n", c.Short)
+	} else {
+		fmt.Fprint(os.Stderr, c.Long)
+	}
 	anyFlags := false
 	c.Fset.VisitAll(func(f *flag.Flag) { anyFlags = true })
 	if anyFlags {

testdata/scripts/cmds.txt

@@ -18,8 +18,12 @@ stderr '^usage: fdroidcl \[-h'
 
 ! fdroidcl search -h
 stderr '^usage: fdroidcl search .*regexp'
+stderr '^Search available apps.'
 stderr '-i.*Filter installed apps'
 
+! fdroidcl install -h
+stderr 'When given no arguments'
+
 ! fdroidcl
 
 ! fdroidcl install -u some.app

testdata/scripts/device.txt

@@ -24,6 +24,11 @@ fdroidcl search -i -q
 fdroidcl search -u -q
 ! stdout 'org\.vi_server\.red_screen'
 
+# install via csv input works as expected
+stdin applist.csv
+fdroidcl install -n
+stdout 'install org\.vi_server\.red_screen:1'
+
 # install version code 1
 fdroidcl install org.vi_server.red_screen:1
 stdout 'Downloading.*red_screen_1.apk'
@@ -57,3 +62,7 @@ stdout 'is up to date'
 
 # uninstall an app that exists
 fdroidcl uninstall org.vi_server.red_screen
+
+-- applist.csv --
+packageName,versionCode,versionName
+org.vi_server.red_screen,1,1.0