Autodetect shell by default

README.md

@@ -244,8 +244,8 @@ Usage of powerline-go:
     	 (default "root,cwd,user,host,ssh,perms,git-branch,git-status,hg,jobs,exit,cwd-path")
   -shell string
     	 Set this to your shell type
-    	 (valid choices: bare, bash, zsh)
-    	 (default "bash")
+    	 (valid choices: autodetect, bare, bash, zsh)
+    	 (default "autodetect")
   -shell-var string
     	 A shell variable to add to the segments.
   -shell-var-no-warn-empty

main.go

@@ -201,9 +201,9 @@ func main() {
 				"(valid choices: default, low-contrast)")),
 		Shell: flag.String(
 			"shell",
-			"bash",
+			"autodetect",
 			commentsWithDefaults("Set this to your shell type",
-				"(valid choices: bare, bash, zsh)")),
+				"(valid choices: autodetect, bare, bash, zsh)")),
 		Modules: flag.String(
 			"modules",
 			"venv,user,host,ssh,cwd,perms,git,hg,jobs,exit,root",

powerline.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"os/user"
+	"path"
 	"strconv"
 	"strings"
 	"sync"
@@ -37,6 +38,7 @@ type powerline struct {
 	username               string
 	pathAliases            map[string]string
 	theme                  Theme
+	shell                  string
 	shellInfo              ShellInfo
 	reset                  string
 	symbolTemplates        Symbols
@@ -80,7 +82,12 @@ func newPowerline(args args, cwd string, priorities map[string]int, align alignm
 	p.userIsAdmin = userIsAdmin()
 
 	p.theme = themes[*args.Theme]
-	p.shellInfo = shellInfos[*args.Shell]
+	if *args.Shell == "autodetect" {
+		p.shell = detectShell(os.Getenv("SHELL"))
+	} else {
+		p.shell = *args.Shell
+	}
+	p.shellInfo = shellInfos[p.shell]
 	p.reset = fmt.Sprintf(p.shellInfo.colorTemplate, "[0m")
 	p.symbolTemplates = symbolTemplates[*args.Mode]
 	p.priorities = priorities
@@ -119,6 +126,19 @@ func newPowerline(args args, cwd string, priorities map[string]int, align alignm
 	return p
 }
 
+func detectShell(envShell string) string {
+	var shell string
+	envShell = path.Base(envShell)
+	if strings.Contains(envShell, "bash") {
+		shell = "bash"
+	} else if strings.Contains(envShell, "zsh") {
+		shell = "zsh"
+	} else {
+		shell = "bare"
+	}
+	return shell
+}
+
 func initSegments(p *powerline, mods []string) {
 	orderedSegments := map[int][]pwl.Segment{}
 	c := make(chan prioritizedSegments, len(mods))

powerline_test.go

@@ -0,0 +1,34 @@
+package main
+
+import "testing"
+
+func Test_detectShell(t *testing.T) {
+	tests := []struct {
+		name string
+		want string
+	}{
+		{
+			name: "",
+			want: "bare",
+		},
+		{
+			name: "/bin/sh",
+			want: "bare",
+		}, {
+			name: "/bin/bash",
+			want: "bash",
+		}, {
+			name: "/usr/local/bin/bash5",
+			want: "bash",
+		}, {
+			name: "/usr/bin/zsh",
+			want: "zsh",
+		}}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := detectShell(tt.name); got != tt.want {
+				t.Errorf("detectShell(%q) = %q, want %q", tt.name, got, tt.want)
+			}
+		})
+	}
+}

segment-hostname.go

@@ -44,9 +44,9 @@ func segmentHost(p *powerline) []pwl.Segment {
 			foreground = p.theme.HostnameColorizedFgMap[background]
 		}
 	} else {
-		if *p.args.Shell == "bash" {
+		if p.shell == "bash" {
 			hostPrompt = "\\h"
-		} else if *p.args.Shell == "zsh" {
+		} else if p.shell == "zsh" {
 			hostPrompt = "%m"
 		} else {
 			hostPrompt = getHostName(p.hostname)

segment-termtitle.go

@@ -19,9 +19,9 @@ func segmentTermTitle(p *powerline) []pwl.Segment {
 		return []pwl.Segment{}
 	}
 
-	if *p.args.Shell == "bash" {
+	if p.shell == "bash" {
 		title = "\\[\\e]0;\\u@\\h: \\w\\a\\]"
-	} else if *p.args.Shell == "zsh" {
+	} else if p.shell == "zsh" {
 		title = "%{\033]0;%n@%m: %~\007%}"
 	} else {
 		cwd := p.cwd

segment-username.go

@@ -6,9 +6,9 @@ import (
 
 func segmentUser(p *powerline) []pwl.Segment {
 	var userPrompt string
-	if *p.args.Shell == "bash" {
+	if p.shell == "bash" {
 		userPrompt = "\\u"
-	} else if *p.args.Shell == "zsh" {
+	} else if p.shell == "zsh" {
 		userPrompt = "%n"
 	} else {
 		userPrompt = p.username