feature: Adds basic implementation.

libevdi/evdi_procfs.c

@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: LGPL-2.1-only
+// Copyright (c) 2015 - 2024 DisplayLink (UK) Ltd.
+
+#include "evdi_lib.h"
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+const int command_length = 50;
+const int name_length = 30;
+
+static FILE *open_process_folder(const char *pid)
+{
+	FILE *pf;
+	char command[command_length];
+
+	snprintf(command, command_length, "/proc/%s/stat", pid);
+	pf = fopen(command, "r");
+
+	return pf;
+}
+
+static void close_folder(FILE *pf)
+{
+	if (fclose(pf) != 0)
+		exit(EXIT_FAILURE);
+}
+
+static char *process_name(FILE *pf)
+{
+	int Xorg_name_len = 6;
+	char *name = (char *)malloc(Xorg_name_len * sizeof(char));
+
+	fscanf(pf, "%*s");
+	fscanf(pf, "%6s", name); // Xorg process had name (Xorg)
+
+	return name;
+}
+
+static bool is_name_Xorg(const char *name)
+{
+	return strstr(name, "Xorg") != NULL;
+}
+
+static bool is_Xorg(const char *pid)
+{
+	FILE *pf;
+	bool result;
+	char *name;
+
+	pf = open_process_folder(pid);
+	if (pf == NULL)
+		return false;
+	name = process_name(pf);
+	result = is_name_Xorg(name);
+
+	close_folder(pf);
+	free(name);
+
+	return result;
+}
+
+static bool is_numeric(const char *str)
+{
+	return str[0] >= '0' && str[0] <= '9';
+}
+
+static bool is_Xorg_process_folder(const struct dirent *proc_entry)
+{
+	const char *folder_name = proc_entry->d_name;
+
+	if (is_numeric(folder_name) && is_Xorg(folder_name))
+		return true;
+
+	return false;
+}
+
+static bool iterate_through_all_process_folders_and_find_Xorg(void)
+{
+	DIR *proc_dir;
+	const struct dirent *proc_entry;
+	bool result = false;
+
+	proc_dir = opendir("/proc");
+	if (proc_dir == NULL)
+		return false;
+
+
+	while ((proc_entry = readdir(proc_dir)) != NULL) {
+		if (is_Xorg_process_folder(proc_entry)) {
+			result = true;
+			break;
+		}
+	}
+
+	closedir(proc_dir);
+	return result;
+}
+
+bool Xorg_running(void)
+{
+	return iterate_through_all_process_folders_and_find_Xorg();
+}