Initial commit

vendor/github.com/jackc/pgpassfile/pgpass.go

@@ -0,0 +1,110 @@
+// Package pgpassfile is a parser PostgreSQL .pgpass files.
+package pgpassfile
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"regexp"
+	"strings"
+)
+
+// Entry represents a line in a PG passfile.
+type Entry struct {
+	Hostname string
+	Port     string
+	Database string
+	Username string
+	Password string
+}
+
+// Passfile is the in memory data structure representing a PG passfile.
+type Passfile struct {
+	Entries []*Entry
+}
+
+// ReadPassfile reads the file at path and parses it into a Passfile.
+func ReadPassfile(path string) (*Passfile, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return ParsePassfile(f)
+}
+
+// ParsePassfile reads r and parses it into a Passfile.
+func ParsePassfile(r io.Reader) (*Passfile, error) {
+	passfile := &Passfile{}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		entry := parseLine(scanner.Text())
+		if entry != nil {
+			passfile.Entries = append(passfile.Entries, entry)
+		}
+	}
+
+	return passfile, scanner.Err()
+}
+
+// Match (not colons or escaped colon or escaped backslash)+. Essentially gives a split on unescaped
+// colon.
+var colonSplitterRegexp = regexp.MustCompile("(([^:]|(\\:)))+")
+
+// var colonSplitterRegexp = regexp.MustCompile("((?:[^:]|(?:\\:)|(?:\\\\))+)")
+
+// parseLine parses a line into an *Entry. It returns nil on comment lines or any other unparsable
+// line.
+func parseLine(line string) *Entry {
+	const (
+		tmpBackslash = "\r"
+		tmpColon     = "\n"
+	)
+
+	line = strings.TrimSpace(line)
+
+	if strings.HasPrefix(line, "#") {
+		return nil
+	}
+
+	line = strings.Replace(line, `\\`, tmpBackslash, -1)
+	line = strings.Replace(line, `\:`, tmpColon, -1)
+
+	parts := strings.Split(line, ":")
+	if len(parts) != 5 {
+		return nil
+	}
+
+	// Unescape escaped colons and backslashes
+	for i := range parts {
+		parts[i] = strings.Replace(parts[i], tmpBackslash, `\`, -1)
+		parts[i] = strings.Replace(parts[i], tmpColon, `:`, -1)
+	}
+
+	return &Entry{
+		Hostname: parts[0],
+		Port:     parts[1],
+		Database: parts[2],
+		Username: parts[3],
+		Password: parts[4],
+	}
+}
+
+// FindPassword finds the password for the provided hostname, port, database, and username. For a
+// Unix domain socket hostname must be set to "localhost". An empty string will be returned if no
+// match is found.
+//
+// See https://www.postgresql.org/docs/current/libpq-pgpass.html for more password file information.
+func (pf *Passfile) FindPassword(hostname, port, database, username string) (password string) {
+	for _, e := range pf.Entries {
+		if (e.Hostname == "*" || e.Hostname == hostname) &&
+			(e.Port == "*" || e.Port == port) &&
+			(e.Database == "*" || e.Database == database) &&
+			(e.Username == "*" || e.Username == username) {
+			return e.Password
+		}
+	}
+	return ""
+}