From f3c58a3923ac467ee3c5057da6799a926aa3fce1 Mon Sep 17 00:00:00 2001
From: Quinn <quinnthepigeon@proton.me>
Date: Thu, 20 Mar 2025 13:59:10 +0100
Subject: [PATCH] implement activation / deactivation

---
 src/main.c | 36 +++++++++++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/main.c b/src/main.c
index b352667..6e2cfc5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,13 +1,24 @@
-#include <stdarg.h>
-#include <stdbool.h>
 #include <stdint.h>
-#include <stdnoreturn.h>
+#include <stdio.h>
 #include <sys/sysinfo.h>
 #include <unistd.h>
 
+#include "cpu.h"
 #include "error.h"
 #include "opts.h"
 
+static inline bool cpu_setter(uint32_t id, bool nstate, uint8_t opts) {
+	bool cstate = !nstate;
+	if (!(opts & OPT_SET_ALL))
+		cstate = getcpu(id);
+
+	if (cstate != nstate) {
+		setcpu(id, nstate);
+		return true;
+	}
+	return false;
+}
+
 int32_t main(int32_t argc, char** argv) {
 	if (geteuid() != 0) fatal("must be executed as the root user!");
 
@@ -18,7 +29,26 @@ int32_t main(int32_t argc, char** argv) {
 	if (opts & OPT_INVERT)
 		ncpus = mcpus - ncpus;
 
+	// validate arguments
 	if (ncpus > mcpus) fatal("%i exeeds the maximum numbers of cpus available (%i)", ncpus, mcpus);
 	if (ncpus < 1) fatal("may not keep less than 1 cpu enabled, requested to enable %i", ncpus);
+
+	char const* const cpu_set_log = "set cpu %i to %hi\n";
+	for (int32_t id = 1; id < mcpus; id++) { // start at CPU 1, as CPU 0 is not writeable
+		if (id <= ncpus) {
+			if (cpu_setter(id, true, opts) && (opts & OPT_VERBOSE))
+				printf(cpu_set_log, id, 1);
+			continue;
+		}
+
+		if (cpu_setter(id, false, opts) && (opts & OPT_VERBOSE))
+			printf(cpu_set_log, id, 0);
+		else if (!(opts & OPT_SET_ALL))
+			break; // break if OPT_SET_ALL is not set (assuming the rest of the CPUs are already off)
+	}
+
+	if ((opts & OPT_LIST_CORES) || (opts & OPT_VERBOSE))
+		printf("%i/%i cpus enabled\n", ncpus, mcpus);
+
 	return 0;
 }