2 files changed, 106 insertions(+), 0 deletions(-)

M README.md
A cmd/rm/main.go

@@ 9,3 9,4 @@ All implemented arguments/flags follow the util-linux equivalent.
 
 - cal
 - touch
+- rm

@@ 0,0 1,105 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io/fs"
+	"os"
+)
+
+const ModeUserWrite = 0o200
+
+func main() {
+	var recursive bool
+	var force bool
+	var rmdir bool
+	var help bool
+
+	flag.BoolVar(&recursive, "r", false, "recursive")
+	flag.BoolVar(&recursive, "recursive", false, "recursive")
+	flag.BoolVar(&force, "f", false, "force")
+	flag.BoolVar(&force, "force", false, "force")
+	flag.BoolVar(&rmdir, "d", false, "rmdir")
+	flag.BoolVar(&rmdir, "dir", false, "rmdir")
+	flag.BoolVar(&help, "h", false, "help")
+	flag.BoolVar(&help, "help", false, "help")
+	flag.Parse()
+
+	if help {
+		fmt.Println(`Usage: rm [OPTION]... [FILE]...
+Remove (unlink) the FILE(s).
+
+  -f, --force           ignore nonexistent files and arguments, never prompt
+  -r, --recursive       remove directories and their contents recursively
+  -d, --dir             remove empty directories
+      --help            display this help and exit
+
+By default, rm does not remove directories.  Use the --recursive (-r)
+option to remove each listed directory, too, along with all of its contents.`)
+		os.Exit(0)
+	}
+
+	if flag.NArg() < 1 {
+		fmt.Println("rm: missing operand")
+		fmt.Println("Try \"rm --help\" for more information.")
+		os.Exit(1)
+	}
+
+	for _, f := range flag.Args() {
+		fi, serr := os.Stat(f)
+		if serr != nil {
+			if errors.Is(serr, fs.ErrNotExist) {
+				fmt.Fprintf(os.Stderr, "rm: cannot remove %q: no such file or directory\n", f)
+			} else {
+				fmt.Fprintf(os.Stderr, "rm: cannot remove %q: %w\n", f, serr)
+			}
+			os.Exit(1)
+		}
+
+		// write-protected
+		if fi.Mode().Perm()&ModeUserWrite == 0 {
+			var propstring string
+			if fi.Mode().IsRegular() {
+				propstring += "regular "
+			}
+			if fi.Size() == 0 {
+				propstring += "empty "
+			}
+
+			fmt.Fprintf(os.Stderr, "rm: remove write-protected %sfile %q? ", propstring, f)
+			var response string
+			fmt.Scanln(&response)
+			if response != "y" {
+				os.Exit(0)
+			}
+		}
+
+		if fi.IsDir() {
+			if rmdir {
+				if err := os.Remove(f); err != nil {
+					if pe, ok := err.(*fs.PathError); ok {
+						fmt.Fprintf(os.Stderr, "rm: cannot remove %q: %s\n", f, pe.Err.Error())
+					} else {
+						fmt.Fprintf(os.Stderr, "rm: cannot remove %q: %s\n", f, err.Error())
+					}
+					os.Exit(1)
+				}
+			}
+			if !recursive {
+				fmt.Fprintf(os.Stderr, "rm: cannot remove %q: is a directory\n", f)
+				os.Exit(1)
+			} else {
+				if rerr := os.RemoveAll(f); rerr != nil {
+					fmt.Fprintln(os.Stderr, rerr.Error())
+					os.Exit(1)
+				}
+			}
+		} else {
+			if err := os.Remove(f); err != nil {
+				fmt.Fprintln(os.Stderr, err.Error())
+				os.Exit(1)
+			}
+		}
+	}
+}