ctx = context.TODO()
cmd := exec.CommandContext(ctx, <some_cmd>, <some_arg>)
fmt.Println(ctx.Err())
Is ctx.Err() is ever going to non-nil with ctx being context.TODO()?
CodePudding user response:
context.TODO().Err() will always return nil, as can be easily seen in the source code:
package context
// An emptyCtx is never canceled, has no values, and has no deadline.
type emptyCtx int
func (*emptyCtx) Err() error {
return nil
}
// ...
var (
todo = new(emptyCtx)
)
// ...
// TODO returns a non-nil, empty Context. Code should use context.TODO when
// it's unclear which Context to use or it is not yet available (because the
// surrounding function has not yet been extended to accept a Context
// parameter).
func TODO() Context {
return todo
}