kill: print --table as vertical (#6216)

* kill: print --table as vertical

* kill: remove signal padding on --table

* kill: skip exit signal in --table

* kill: replace "skip" with "filter"

---------

Co-authored-by: Daniel Hofstetter <daniel.hofstetter@42dh.com>

src/uu/kill/src/kill.rs

@@ -142,15 +142,14 @@ fn handle_obsolete(args: &mut Vec<String>) -> Option<usize> {
 }
 
 fn table() {
-    let name_width = ALL_SIGNALS.iter().map(|n| n.len()).max().unwrap();
-
-    for (idx, signal) in ALL_SIGNALS.iter().enumerate() {
-        print!("{0: >#2} {1: <#2$}", idx, signal, name_width + 2);
-        if (idx + 1) % 7 == 0 {
-            println!();
+    // GNU kill doesn't list the EXIT signal with --table, so we ignore it, too
+    for (idx, signal) in ALL_SIGNALS
+        .iter()
+        .enumerate()
+        .filter(|(_, s)| **s != "EXIT")
+    {
+        println!("{0: >#2} {1}", idx, signal);
     }
-    }
-    println!();
 }
 
 fn print_signal(signal_name_or_value: &str) -> UResult<()> {

tests/by-util/test_kill.rs

@@ -83,6 +83,29 @@ fn test_kill_list_all_signals_as_table() {
         .stdout_contains("HUP");
 }
 
+#[test]
+fn test_kill_table_starts_at_1() {
+    new_ucmd!()
+        .arg("-t")
+        .succeeds()
+        .stdout_matches(&Regex::new("^\\s?1\\sHUP").unwrap());
+}
+
+#[test]
+fn test_kill_table_lists_all_vertically() {
+    // Check for a few signals.  Do not try to be comprehensive.
+    let command = new_ucmd!().arg("-t").succeeds();
+    let signals = command
+        .stdout_str()
+        .split('\n')
+        .flat_map(|line| line.trim().split(" ").nth(1))
+        .collect::<Vec<&str>>();
+
+    assert!(signals.contains(&"KILL"));
+    assert!(signals.contains(&"TERM"));
+    assert!(signals.contains(&"HUP"));
+}
+
 #[test]
 fn test_kill_list_one_signal_from_name() {
     // Use SIGKILL because it is 9 on all unixes.