pgrep: Add -l option to list the process name as well as its pid

Author: tcl3

Base/usr/share/man/man1/pgrep.md

@@ -5,14 +5,15 @@ pgrep - look up processes based on name
 ## Synopsis
 
 ```sh
-$ pgrep [--count] [-d delimiter] [--ignore-case] [--invert-match] <process-name>
+$ pgrep [--count] [-d delimiter] [--ignore-case] [--list-name] [--invert-match] <process-name>
 ```
 
 ## Options
 
 * `-c`, `--count`: Suppress normal output and print the number of matching processes
 * `-d`, `--delimiter`: Set the string used to delimit multiple pids
 * `-i`, `--ignore-case`: Make matches case-insensitive
+* `-l`, `--list-name`: List the process name in addition to its pid
 * `-v`, `--invert-match`: Select non-matching lines
 
 ## Arguments

Userland/Utilities/pgrep.cpp

@@ -23,13 +23,15 @@ ErrorOr<int> serenity_main(Main::Arguments args)
     bool display_number_of_matches = false;
     auto pid_delimiter = "\n"sv;
     bool case_insensitive = false;
+    bool list_process_name = false;
     bool invert_match = false;
     StringView pattern;
 
     Core::ArgsParser args_parser;
     args_parser.add_option(display_number_of_matches, "Suppress normal output and print the number of matching processes", "count", 'c');
     args_parser.add_option(pid_delimiter, "Set the string used to delimit multiple pids", "delimiter", 'd', nullptr);
     args_parser.add_option(case_insensitive, "Make matches case-insensitive", "ignore-case", 'i');
+    args_parser.add_option(list_process_name, "List the process name in addition to its pid", "list-name", 'l');
     args_parser.add_option(invert_match, "Select non-matching lines", "invert-match", 'v');
     args_parser.add_positional_argument(pattern, "Process name to search for", "process-name");
     args_parser.parse(args);
@@ -45,24 +47,27 @@ ErrorOr<int> serenity_main(Main::Arguments args)
 
     auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
 
-    Vector<pid_t> matches;
-    for (auto& it : all_processes.processes) {
+    Vector<Core::ProcessStatistics> matches;
+    for (auto const& it : all_processes.processes) {
         auto result = re.match(it.name, PosixFlags::Global);
         if (result.success ^ invert_match) {
-            matches.append(it.pid);
+            matches.append(it);
         }
     }
 
     if (display_number_of_matches) {
         outln("{}", matches.size());
     } else {
-        quick_sort(matches);
+        quick_sort(matches, [](auto const& a, auto const& b) { return a.pid < b.pid; });
         auto displayed_at_least_one = false;
         for (auto& match : matches) {
             if (displayed_at_least_one)
-                out("{}{}"sv, pid_delimiter, match);
-            else
-                out("{}"sv, match);
+                out("{}"sv, pid_delimiter);
+
+            out("{}"sv, match.pid);
+
+            if (list_process_name)
+                out(" {}"sv, match.name);
 
             displayed_at_least_one = true;
         }