provide better error on invalid flag

Add a extra `See 'podman command --help'` to the error output.
With this patch you now get:
```
$ podman run -h
Error: flag needs an argument: 'h' in -h
See 'podman run --help'
```

Fixes #13082
Fixes #13002

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/cmd/podman/main.go b/cmd/podman/main.go
index 9850f5d27..4f8131653 100644
--- a/cmd/podman/main.go
+++ b/cmd/podman/main.go
@@ -72,6 +72,8 @@ func parseCommands() *cobra.Command {
 		}
 		parent.AddCommand(c.Command)
 
+		c.Command.SetFlagErrorFunc(flagErrorFuncfunc)
+
 		// - templates need to be set here, as PersistentPreRunE() is
 		// not called when --help is used.
 		// - rootCmd uses cobra default template not ours
@@ -84,5 +86,11 @@ func parseCommands() *cobra.Command {
 		os.Exit(1)
 	}
 
+	rootCmd.SetFlagErrorFunc(flagErrorFuncfunc)
 	return rootCmd
 }
+
+func flagErrorFuncfunc(c *cobra.Command, e error) error {
+	e = fmt.Errorf("%w\nSee '%s --help'", e, c.CommandPath())
+	return e
+}