tail: Add documentation for Settings::check_warnings and Settings::ve…

…rify

src/uu/tail/src/args.rs

@@ -245,6 +245,8 @@ impl Settings {
  self.inputs.len()
  }
 
+ /// Check [`Settings`] for problematic configurations of tail originating from user provided
+ /// command line arguments and print appropriate warnings.
  pub fn check_warnings(&self) {
  if self.retry {
  if self.follow.is_none() {
@@ -262,6 +264,10 @@ impl Settings {
  }
  }
 
+ // This warning originates from gnu's tail implementation of the equivalent warning. If the
+ // user wants to follow stdin, but tail is blocking indefinitely anyways, because of stdin
+ // as `tty` (but no otherwise blocking stdin), then we print a warning that `--follow`
+ // cannot be applied under these circumstances and is therefore ineffective.
  if self.follow.is_some() && self.has_stdin() {
  let blocking_stdin = self.pid == 0
  && self.follow == Some(FollowMode::Descriptor)
@@ -279,6 +285,10 @@ impl Settings {
  }
  }
 
+ /// Verify [`Settings`] and try to find unsolvable misconfigurations of tail originating from
+ /// user provided command line arguments. In contrast to [`Settings::check_warnings`] these
+ /// misconfigurations usually lead to the immediate exit or abortion of the running `tail`
+ /// process.
  pub fn verify(&self) -> VerificationResult {
  // Mimic GNU's tail for `tail -F`
  if self.inputs.iter().any(|i| i.is_stdin()) && self.follow == Some(FollowMode::Name) {