From 6eba3996139cc639e2f10fb79cdc5afdaecd689f Mon Sep 17 00:00:00 2001
From: jienfak <jienfak@protonmail.com>
Date: Sun, 8 Mar 2020 05:24:41 +0500
Subject: [PATCH] ls: Added simple implementation.

---
 goblin.go |   2 +
 ls/ls.go  | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 ls/ls.go

diff --git a/goblin.go b/goblin.go
index d539a57..608f540 100644
--- a/goblin.go
+++ b/goblin.go
@@ -11,6 +11,7 @@ import(
 	"github.com/jienfak/goblin/gfalse"
 	"github.com/jienfak/goblin/sort"
 	"github.com/jienfak/goblin/tac"
+	"github.com/jienfak/goblin/ls"
 )
 
 func main() {
@@ -28,6 +29,7 @@ func main() {
 		"false" : gfalse.Run,
 		"sort" : sort.Run,
 		"tac" : tac.Run,
+		"ls" : ls.Run,
 	}
 
 	if binBase := path.Base(os.Args[0]) ; binBase != "goblin" {
diff --git a/ls/ls.go b/ls/ls.go
new file mode 100644
index 0000000..3f50b25
--- /dev/null
+++ b/ls/ls.go
@@ -0,0 +1,108 @@
+package ls
+import(
+	"os"
+	"fmt"
+	"flag"
+	"strings"
+)
+
+func IsDir(p string) (bool, error) {
+	finfo, e := os.Stat(p)
+	if e != nil {
+		return false, e
+	}
+	return finfo.IsDir(), e
+}
+
+func ReadDir(p string) ([]os.FileInfo, error) {
+	f, e := os.Open(p)
+	if e != nil {
+		return nil, e
+	}
+	l, e := f.Readdir(-1)
+	if e != nil {
+			return nil, e
+	}
+	f.Close()
+
+	return l, nil
+}
+
+func Stat(p string) (os.FileInfo, error) {
+	f, e := os.Open(p)
+	if e != nil {
+		return nil, e
+	}
+	s, e := f.Stat()
+	f.Close()
+	return s, nil
+}
+
+func ls(p string, fold int) error {
+	if fold == 0 {
+		return nil
+	}
+	isDir, e := IsDir(p)
+	if e != nil {
+		return e
+	}
+
+	pp := strings.TrimRight(p, "/")
+	if isDir {
+		l, e := ReadDir(p)
+
+		if e != nil {
+			return e
+		}
+		for _, f := range l {
+			s := pp+"/"+f.Name()
+			fmt.Println(s)
+			ls(s, fold-1)
+		}
+	} else {
+		f, e := Stat(p)	
+		if e != nil {
+			return e
+		}
+		fmt.Println(f.Name())
+	}
+	return nil
+}
+
+func Run(args []string) int {
+	var(
+		foldLvl int
+	)
+	status := 0
+	arg0 := args[0]
+	args = args[1:]
+	flagSet := flag.NewFlagSet(arg0, flag.ExitOnError)
+	flagSet.IntVar(&foldLvl, "r", 1, "List recursively with choosing deepness.")
+	flagSet.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage of %s: %s [files]\n", arg0, arg0)
+		flagSet.PrintDefaults()
+	}
+	flagSet.Parse(args)
+	args = flagSet.Args()
+	if len(args) == 0 {
+		l, e := ReadDir(".")
+		if e != nil {
+			status = 1
+			fmt.Fprintf(os.Stderr, "%s: %s.\n", arg0, e)
+		} else {
+			for _, f := range l {
+				fmt.Println(f.Name())
+			}
+		}
+	} else {
+		for _, p := range args {
+			e := ls(p, foldLvl)
+			if e != nil {
+				status = 1
+				fmt.Fprintf(os.Stderr, "%s: %s.\n", arg0, e)
+			}
+			
+		}
+	}
+	return status
+}