os: delete os.EINVAL and so on
The set of errors forwarded by the os package varied with system and
was therefore non-portable.
Three helpers added for portable error checking: IsExist, IsNotExist, and IsPermission.
One or two more may need to come, but let's keep the set very small to discourage
thinking about errors that way.
R=mikioh.mikioh, gustavo, r, rsc
CC=golang-dev
https://golang.org/cl/5672047
diff --git a/src/pkg/os/error.go b/src/pkg/os/error.go
index 135cdae..5baeba4 100644
--- a/src/pkg/os/error.go
+++ b/src/pkg/os/error.go
@@ -4,6 +4,18 @@
package os
+import (
+ "errors"
+)
+
+// Portable analogs of some common system call errors.
+var (
+ ErrInvalid = errors.New("invalid argument")
+ ErrPermission = errors.New("permission denied")
+ ErrExist = errors.New("file already exists")
+ ErrNotExist = errors.New("file does not exit")
+)
+
// PathError records an error and the operation and file path that caused it.
type PathError struct {
Op string
