feat: Dodane parsowanie pliku pgpass

pgpass jest prsowany i przy uruchomieniu psql podawane jest
wybrane hasło pasujące do połaczenia

pass/pass.go

@@ -0,0 +1,81 @@
+package pass
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+)
+
+type pgpassrow struct {
+	hostname string
+	port     string
+	database string
+	username string
+	password string
+}
+
+type PassDb struct {
+	db []pgpassrow
+	cache map[string]*pgpassrow
+}
+
+func Load(file string, master string) (*PassDb, error) {
+
+	data, err := os.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+
+	lines := bytes.Split(data, []byte{'\n'})
+
+	var rows []pgpassrow
+
+	for i, line := range lines {
+		line = bytes.TrimRight(line, "\n\r \t")
+		if len(line) == 0 || line[0] == byte('#') {
+			continue
+		}
+		fields := bytes.Split(line, []byte{':'})
+		if len(fields) != 5 {
+			return nil, fmt.Errorf("błąd w pliku hasłeł %s:%d: niewłaściwa liczba pól", file, i)
+		}
+		rows = append(rows, pgpassrow{
+			hostname: string(fields[0]),
+			port:     string(fields[1]),
+			database: string(fields[2]),
+			username: string(fields[3]),
+			password: string(fields[4]),
+		})
+	}
+
+	return &PassDb{
+		db: rows,
+		cache: make(map[string]*pgpassrow),
+	}, nil
+}
+
+func match(value string, pattern string) bool {
+	return pattern == "*" || pattern == value
+}
+
+func (self *PassDb) FindPassword(host string, port uint, database string, user string) string {
+	myport := fmt.Sprintf("%d", port)
+	key := fmt.Sprintf("%s:%s:%s:%s", host, myport, database, user)
+	cached, ok := self.cache[key]
+	if ok {
+		return cached.password
+	}
+
+	// pierwszy pasujący do wzorca
+	for i := range self.db {
+		if match(host, self.db[i].hostname) &&
+			match(myport, self.db[i].port) &&
+			match(database, self.db[i].database) &&
+			match(user, self.db[i].username) {
+
+				self.cache[key] = &self.db[i]
+				return self.db[i].password
+		}
+	}
+	return ""
+}