pgrep: Add `-c` option to show the number of matches

1 files changed, 16 insertions, 11 deletions

diff --git a/Userland/Utilities/pgrep.cpp b/Userland/Utilities/pgrep.cpp
index 4c7fa0b29c..5cc16839dc 100644
--- a/Userland/Utilities/pgrep.cpp
+++ b/Userland/Utilities/pgrep.cpp
@@ -20,12 +20,14 @@ ErrorOr<int> serenity_main(Main::Arguments args)
     TRY(Core::System::unveil("/etc/passwd", "r"));
     TRY(Core::System::unveil(nullptr, nullptr));
 
+    bool display_number_of_matches = false;
     auto pid_delimiter = "\n"sv;
     bool case_insensitive = 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(invert_match, "Select non-matching lines", "invert-match", 'v');
@@ -51,20 +53,23 @@ ErrorOr<int> serenity_main(Main::Arguments args)
         }
     }
 
-    quick_sort(matches);
+    if (display_number_of_matches) {
+        outln("{}", matches.size());
+    } else {
+        quick_sort(matches);
+        auto displayed_at_least_one = false;
+        for (auto& match : matches) {
+            if (displayed_at_least_one)
+                out("{}{}"sv, pid_delimiter, match);
+            else
+                out("{}"sv, match);
 
-    auto displayed_at_least_one = false;
-    for (auto& match : matches) {
-        if (displayed_at_least_one)
-            out("{}{}"sv, pid_delimiter, match);
-        else
-            out("{}"sv, match);
+            displayed_at_least_one = true;
+        }
 
-        displayed_at_least_one = true;
+        if (displayed_at_least_one)
+            outln();
     }
 
-    if (displayed_at_least_one)
-        outln();
-
     return matches.size() > 0 ? 0 : 1;
 }