initial commit [141.14.129.234,mike]

util.go

@@ -0,0 +1,94 @@
+package main
+
+import (
+	"bytes"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func word(words []string, i int) string {
+	if i < len(words) {
+		return words[i]
+	}
+	return ""
+}
+
+// splitLines splits s on newlines, dropping a trailing newline and returning
+// nil for empty input.
+func splitLines(s string) []string {
+	s = strings.TrimRight(s, "\n")
+	if s == "" {
+		return nil
+	}
+	return strings.Split(s, "\n")
+}
+
+func isDir(p string) bool {
+	fi, err := os.Stat(p)
+	return err == nil && fi.IsDir()
+}
+
+// truthy reports whether a config string means "on" (1/true/yes/on).
+func truthy(s string) bool {
+	switch strings.ToLower(strings.TrimSpace(s)) {
+	case "1", "true", "yes", "on":
+		return true
+	}
+	return false
+}
+
+func fileExists(p string) bool {
+	fi, err := os.Stat(p)
+	return err == nil && !fi.IsDir()
+}
+
+func filesEqual(a, b string) bool {
+	da, ea := os.ReadFile(a)
+	db, eb := os.ReadFile(b)
+	if ea != nil || eb != nil {
+		return false
+	}
+	return bytes.Equal(da, db)
+}
+
+func copyFile(src, dst string) error {
+	data, err := os.ReadFile(src)
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
+		return err
+	}
+	mode := os.FileMode(0644)
+	if fi, err := os.Stat(src); err == nil {
+		mode = fi.Mode()
+	}
+	return os.WriteFile(dst, data, mode)
+}
+
+func resolveIP() string {
+	h, err := os.Hostname()
+	if err != nil {
+		return ""
+	}
+	addrs, err := net.LookupHost(h)
+	if err != nil || len(addrs) == 0 {
+		return ""
+	}
+	for _, a := range addrs {
+		if ip := net.ParseIP(a); ip != nil && ip.To4() != nil {
+			return a
+		}
+	}
+	return addrs[0]
+}
+
+func shortHostname() string {
+	h, _ := os.Hostname()
+	if i := strings.IndexByte(h, '.'); i >= 0 {
+		h = h[:i]
+	}
+	return h
+}