pkill: Simplify short signal number option handling

Translate short signal options like '-TERM' to '--signal=TERM' to simplify
the code and also properly handle the case where both short and long
form is used at the same time.

Change parsing of the SigCgt field to use u64, as there are more than 32
signals.

Author: dezgeg

src/uu/pkill/src/pkill.rs

@@ -52,7 +52,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     #[cfg(target_os = "windows")]
     let args = args.collect_ignore();
     #[cfg(unix)]
-    let obs_signal = handle_obsolete(&mut args);
+    handle_obsolete(&mut args);
 
     let matches = uu_app().try_get_matches_from(&args)?;
 
@@ -96,13 +96,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
 
     // Parse signal
     #[cfg(unix)]
-    let sig_num = if let Some(signal) = obs_signal {
-        signal
-    } else if let Some(signal) = matches.get_one::<String>("signal") {
-        parse_signal_value(signal)?
-    } else {
-        15_usize //SIGTERM
-    };
+    let sig_num = parse_signal_value(matches.get_one::<String>("signal").unwrap())?;
 
     #[cfg(unix)]
     let sig_name = signal_name_by_value(sig_num);
@@ -125,7 +119,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         if matches.get_flag("require-handler") {
             pids.retain(|pid| {
                 let mask =
-                    u32::from_str_radix(pid.clone().status().get("SigCgt").unwrap(), 16).unwrap();
+                    u64::from_str_radix(pid.clone().status().get("SigCgt").unwrap(), 16).unwrap();
                 mask & (1 << sig_num) != 0
             });
         }
@@ -293,7 +287,7 @@ fn process_flag_o_n(
 }
 
 #[cfg(unix)]
-fn handle_obsolete(args: &mut Vec<String>) -> Option<usize> {
+fn handle_obsolete(args: &mut [String]) {
     // Sanity check
     if args.len() > 2 {
         // Old signal can only be in the first argument position
@@ -302,13 +296,11 @@ fn handle_obsolete(args: &mut Vec<String>) -> Option<usize> {
             // Check if it is a valid signal
             let opt_signal = signal_by_name_or_value(signal);
             if opt_signal.is_some() {
-                // remove the signal before return
-                args.remove(1);
-                return opt_signal;
+                // Replace with long option that clap can parse
+                args[1] = format!("--signal={}", signal);
             }
         }
     }
-    None
 }
 
 #[cfg(unix)]
@@ -372,7 +364,8 @@ pub fn uu_app() -> Command {
             // arg!(-s --session <SID>        "match session IDs")
             //     .value_delimiter(',')
             //     .value_parser(clap::value_parser!(u64)),
-            arg!(--signal <sig>            "signal to send (either number or name)"),
+            arg!(--signal <sig>            "signal to send (either number or name)")
+                .default_value("SIGTERM"),
             arg!(-t --terminal <tty>       "match by controlling terminal").value_delimiter(','),
             // arg!(-u --euid <ID>            "match by effective IDs")
             //     .value_delimiter(',')