func getPasswd()

in google_guest_agent/non_windows_accounts.go [246:299]
48 lines of code
12 McCabe index (conditional complexity)

func getPasswd(user string) (*passwdEntry, error) {
	prefix := []byte(user + ":")
	colon := []byte{':'}

	parse := func(line []byte) (*passwdEntry, error) {
		if !bytes.HasPrefix(line, prefix) || bytes.Count(line, colon) < 6 {
			return nil, nil
		}
		// kevin:x:1005:1006::/home/kevin:/usr/bin/zsh
		parts := strings.SplitN(string(line), ":", 7)
		if len(parts) < 7 {
			return nil, fmt.Errorf("invalid passwd entry for %s", user)
		}
		uid, err := strconv.Atoi(parts[2])
		if err != nil {
			return nil, fmt.Errorf("invalid passwd entry for %s", user)
		}
		gid, err := strconv.Atoi(parts[3])
		if err != nil {
			return nil, fmt.Errorf("invalid passwd entry for %s", user)
		}
		u := &passwdEntry{
			Username: parts[0],
			Passwd:   parts[1],
			UID:      uid,
			GID:      gid,
			Name:     parts[4],
			HomeDir:  parts[5],
			Shell:    parts[6],
		}
		return u, nil
	}

	passwd, err := os.Open("/etc/passwd")
	if err != nil {
		return nil, err
	}
	bs := bufio.NewScanner(passwd)
	for bs.Scan() {
		line := bs.Bytes()
		// There's no spec for /etc/passwd or /etc/group, but we try to follow
		// the same rules as the glibc parser, which allows comments and blank
		// space at the beginning of a line.
		line = bytes.TrimSpace(line)
		if len(line) == 0 || line[0] == '#' {
			continue
		}
		v, err := parse(line)
		if v != nil || err != nil {
			return v, err
		}
	}
	return nil, fmt.Errorf("user not found")
}