add lib/pq

vendor/github.com/lib/pq/internal/pqutil/path.go

@@ -0,0 +1,91 @@
+package pqutil
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/user"
+	"path/filepath"
+	"runtime"
+	"syscall"
+)
+
+// Home gets the PostgreSQL configuration dir in the user's home directory:
+// %APPDATA%/postgresql on Windows, and $HOME/.postgresql/postgresql.crt
+// everywhere else.
+//
+// Returns an empy string if no home directory was found.
+//
+// Matches pqGetHomeDirectory() from PostgreSQL.
+// https://github.com/postgres/postgres/blob/2b117bb/src/interfaces/libpq/fe-connect.c#L8214
+func Home(subdir bool) string {
+	if runtime.GOOS == "windows" {
+		// pq uses SHGetFolderPath(), which is deprecated but x/sys/windows has
+		// KnownFolderPath(). We don't really want to pull that in though, so
+		// use APPDATA env. This is also what PostgreSQL uses in some other
+		// codepaths (get_home_path() for example).
+		ad := os.Getenv("APPDATA")
+		if ad == "" {
+			return ""
+		}
+		return filepath.Join(ad, "postgresql")
+	}
+
+	home, _ := os.UserHomeDir()
+	if home == "" {
+		u, err := user.Current()
+		if err != nil {
+			return ""
+		}
+		home = u.HomeDir
+	}
+	// libpq reads some files from ~/ and some from ~/.postgresql – on Windows
+	// it always uses %APPDATA%/postgresql.
+	if subdir {
+		home = filepath.Join(home, ".postgresql")
+	}
+	return home
+}
+
+// ErrNotExists reports if err is a "path doesn't exist" type error.
+//
+// fs.ErrNotExist is not enough, as "/dev/null/somefile" will return ENOTDIR
+// instead of ENOENT.
+func ErrNotExists(err error) bool {
+	perr := new(os.PathError)
+	if errors.As(err, &perr) && (perr.Err == syscall.ENOENT || perr.Err == syscall.ENOTDIR) {
+		return true
+	}
+	return false
+}
+
+var WarnFD io.Writer = os.Stderr
+
+// Pgpass gets the filepath to the pgpass file to use, returning "" if a pgpass
+// file shouldn't be used.
+func Pgpass(passfile string) string {
+	// Get passfile from the options.
+	if passfile == "" {
+		home := Home(false)
+		if home == "" {
+			return ""
+		}
+		passfile = filepath.Join(home, ".pgpass")
+	}
+
+	// On Win32, the directory is protected, so we don't have to check the file.
+	if runtime.GOOS != "windows" {
+		fi, err := os.Stat(passfile)
+		if err != nil {
+			return ""
+		}
+		if fi.Mode().Perm()&(0x77) != 0 {
+			fmt.Fprintf(WarnFD,
+				"WARNING: password file %q has group or world access; permissions should be u=rw (0600) or less\n",
+				passfile)
+			return ""
+		}
+	}
+	return passfile
+}