2021: new from template

2021/new/main.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	_ "embed"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"text/template"
+)
+
+//go:embed main.tmpl
+var content string
+
+type Data struct{ N int }
+
+func main() {
+	if err := Main(); err != nil {
+		fmt.Fprintln(os.Stderr, err.Error())
+		os.Exit(1)
+	}
+}
+
+func Main() error {
+	t, err := template.New("main").Parse(content)
+	if err != nil {
+		return err
+	}
+
+	n, err := strconv.Atoi(os.Args[1])
+	if err != nil {
+		return err
+	}
+
+	dir := fmt.Sprintf("day%d", n)
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return err
+	}
+
+	main := filepath.Join(dir, "main.go")
+	if err := writeMain(t, Data{N: n}, main); err != nil {
+		return err
+	}
+
+	input := filepath.Join("input", fmt.Sprintf("day%d.txt", n))
+	if err := touch(input); err != nil {
+		return err
+	}
+	return nil
+}
+
+func writeMain(t *template.Template, data Data, path string) error {
+	f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o644)
+	if err != nil {
+		return err
+	}
+	// Prefer the write error over the close error.
+	werr := t.Execute(f, data)
+	cerr := f.Close()
+	if werr != nil {
+		return werr
+	}
+	return cerr
+}
+
+func touch(path string) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	return f.Close()
+}

2021/new/main.tmpl

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/jdkaplan/advent-of-code/aoc"
+)
+
+func main() {
+	lines := aoc.Input().ReadLines("day{{ .N }}.txt")
+	fmt.Println(part1(lines))
+}
+
+func part1(lines []string) int {
+	return 0
+}