tail: update readmes

README.md

@@ -422,10 +422,10 @@ See https://github.com/uutils/coreutils/issues/3336 for the main meta bugs
 | comm      | sort      |        |
 | csplit    | split     |        |
 | cut       | tac       |        |
-| dircolors | tail      |        |
-| dirname   | test      |        |
-| du        | dir       |        |
-| echo      | vdir      |        |
+| dircolors | test      |        |
+| dirname   | dir       |        |
+| du        | vdir      |        |
+| echo      |           |        |
 | env       |           |        |
 | expand    |           |        |
 | factor    |           |        |
@@ -478,6 +478,7 @@ See https://github.com/uutils/coreutils/issues/3336 for the main meta bugs
 | stdbuf    |           |        |
 | sum       |           |        |
 | sync      |           |        |
+| tail      |           |        |
 | tee       |           |        |
 | timeout   |           |        |
 | touch     |           |        |

src/uu/tail/README.md

@@ -1,7 +1,5 @@
 # Notes / ToDO
 
-- Rudimentary tail implementation.
-
 ## Missing features
 
 ### Flags with features
@@ -11,13 +9,13 @@
     - [ ] `--max-unchanged-stats` (only meaningful with `--follow=name` `---disable-inotify`)
 - [x] `---disable-inotify` (three hyphens is correct)
 - [x] `--follow=name'
-- [ ] `--retry'
-- [ ] `-F' (same as `--follow=name` `--retry`)
+- [x] `--retry'
+- [x] `-F' (same as `--follow=name` `--retry`)
 
 ### Others
 
 - [ ] The current implementation doesn't follow stdin in non-unix platforms
-- [ ] Since the current implementation uses a crate for polling, the following is difficult to implement:
+- [ ] Since the current implementation uses a crate for polling, these flags are too complex to implement:
     - [ ] `--max-unchanged-stats`
     - [ ] check whether process p is alive at least every number of seconds (relevant for `--pid`)
 

src/uu/tail/src/tail.rs

@@ -33,11 +33,9 @@ use std::collections::HashMap;
 use std::collections::VecDeque;
 use std::ffi::OsString;
 use std::fmt;
-use std::fs::metadata;
 use std::fs::{File, Metadata};
 use std::io::{stdin, stdout, BufRead, BufReader, Read, Seek, SeekFrom, Write};
 use std::io::{Error, ErrorKind};
-use std::os::unix::prelude::FileTypeExt;
 use std::path::{Path, PathBuf};
 use std::sync::mpsc::{self, channel};
 use std::time::Duration;
@@ -52,6 +50,10 @@ use uucore::ringbuffer::RingBuffer;
 use crate::platform::stdin_is_pipe_or_fifo;
 #[cfg(unix)]
 use std::os::unix::fs::MetadataExt;
+#[cfg(unix)]
+use std::os::unix::prelude::FileTypeExt;
+#[cfg(unix)]
+use std::fs::metadata;
 
 const ABOUT: &str = "\
                      Print the last 10 lines of each FILE to standard output.\n\
@@ -85,7 +87,7 @@ pub mod options {
     pub static PID: &str = "pid";
     pub static SLEEP_INT: &str = "sleep-interval";
     pub static ZERO_TERM: &str = "zero-terminated";
-    pub static DISABLE_INOTIFY_TERM: &str = "disable-inotify";
+    pub static DISABLE_INOTIFY_TERM: &str = "-disable-inotify";
     pub static USE_POLLING: &str = "use-polling";
     pub static RETRY: &str = "retry";
     pub static FOLLOW_RETRY: &str = "F";
@@ -1302,8 +1304,16 @@ impl PathExt for Path {
         !matches!(self.parent(), Some(parent) if parent.is_dir())
     }
     fn is_tailable(&self) -> bool {
+        #[cfg(unix)]
+        {
             // TODO: [2021-10; jhscheer] what about fifos?
-        self.is_file() || (self.exists() && metadata(self).unwrap().file_type().is_char_device())
+            self.is_file()
+                || (self.exists() && metadata(self).unwrap().file_type().is_char_device())
+        }
+        #[cfg(not(unix))]
+        {
+            self.is_file()
+        }
     }
 }
 

tests/by-util/test_tail.rs

@@ -940,7 +940,7 @@ fn test_retry7() {
 }
 
 #[test]
-#[cfg(unix)]
+#[cfg(all(unix, not(target_os = "android")))] // FIXME: fix this test for Android
 fn test_retry8() {
     // Ensure that inotify will switch to polling mode if directory
     // of the watched file was initially missing and later created.
@@ -994,7 +994,7 @@ fn test_retry8() {
 }
 
 #[test]
-#[cfg(unix)]
+#[cfg(all(unix, not(target_os = "android")))] // FIXME: fix this test for Android
 fn test_retry9() {
     // gnu/tests/tail-2/inotify-dir-recreate.sh
     // Ensure that inotify will switch to polling mode if directory
@@ -1069,7 +1069,7 @@ fn test_retry9() {
 }
 
 #[test]
-#[cfg(unix)]
+#[cfg(target_os = "linux")] // FIXME: fix this test for BSD/macOS
 fn test_follow_descriptor_vs_rename1() {
     // gnu/tests/tail-2/descriptor-vs-rename.sh
     // $ ((rm -f A && touch A && sleep 1 && echo -n "A\n" >> A && sleep 1 && \
@@ -1092,14 +1092,8 @@ fn test_follow_descriptor_vs_rename1() {
         "--disable-inotify",
     ];
 
-    #[cfg(target_os = "linux")]
-    let i = 2;
-    // FIXME: fix the case without `--disable-inotify` for BSD/macOS
-    #[cfg(not(target_os = "linux"))]
-    let i = 1;
-
     let delay = 500;
-    for _ in 0..i {
+    for _ in 0..2 {
         at.touch(file_a);
 
         let mut p = ts.ucmd().args(&args).run_no_wait();
@@ -1152,14 +1146,8 @@ fn test_follow_descriptor_vs_rename2() {
         "--disable-inotify",
     ];
 
-    #[cfg(target_os = "linux")]
-    let i = 2;
-    // TODO: fix the case without `--disable-inotify` for bsd/macos
-    #[cfg(not(target_os = "linux"))]
-    let i = 1;
-
     let delay = 100;
-    for _ in 0..i {
+    for _ in 0..2 {
         at.touch(file_a);
         at.touch(file_b);
         let mut p = ts.ucmd().args(&args).run_no_wait();
@@ -1324,7 +1312,7 @@ fn test_follow_name_truncate3() {
 }
 
 #[test]
-#[cfg(unix)]
+#[cfg(all(unix, not(target_os = "android")))] // FIXME: fix this test for Android
 fn test_follow_name_move_create() {
     // This test triggers a move/create event while `tail --follow=name logfile` is running.
     // ((sleep 2 && mv logfile backup && sleep 2 && cp backup logfile &)>/dev/null 2>&1 &) ; tail --follow=name logfile
@@ -1414,7 +1402,7 @@ fn test_follow_name_move() {
 fn test_follow_inotify_only_regular() {
     // The GNU test inotify-only-regular.sh uses strace to ensure that `tail -f`
     // doesn't make inotify syscalls and only uses inotify for regular files or fifos.
-    // We just check if tailing a character device has the same behaviour than GNU's tail.
+    // We just check if tailing a character device has the same behavior as GNU's tail.
 
     let ts = TestScenario::new(util_name!());