From 123d11e4e37094f350bb377398d61e29eda60b13 Mon Sep 17 00:00:00 2001
From: EnderIce2 <enderice2@protonmail.com>
Date: Thu, 20 Feb 2025 02:07:04 +0200
Subject: [PATCH] feat(userspace/libc): implement system() function

Signed-off-by: EnderIce2 <enderice2@protonmail.com>
---
 Userspace/libc/include/stdlib.h |  2 +-
 Userspace/libc/src/std/stdlib.c | 51 ++++++++++++++++++++++++++++++++-
 2 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/Userspace/libc/include/stdlib.h b/Userspace/libc/include/stdlib.h
index 72423123..fb156d9f 100644
--- a/Userspace/libc/include/stdlib.h
+++ b/Userspace/libc/include/stdlib.h
@@ -103,7 +103,7 @@ extern "C"
 	long strtol(const char *restrict nptr, char **restrict endptr, int base);
 	long long strtoll(const char *restrict nptr, char **restrict endptr, int base);
 	unsigned long int strtoul(const char *, char **, int);
-	int system(const char *);
+	int system(const char *command);
 	int ttyslot(void);
 	int unlockpt(int);
 	void *valloc(size_t);
diff --git a/Userspace/libc/src/std/stdlib.c b/Userspace/libc/src/std/stdlib.c
index 2d9a643e..ef80e9fc 100644
--- a/Userspace/libc/src/std/stdlib.c
+++ b/Userspace/libc/src/std/stdlib.c
@@ -330,7 +330,56 @@ export long long strtoll(const char *restrict nptr, char **restrict endptr, int
 }
 
 export unsigned long int strtoul(const char *, char **, int);
-export int system(const char *);
+
+export int system(const char *command)
+{
+	if (command == NULL)
+		return 1;
+
+	pid_t pid;
+	int status;
+	struct sigaction sa, old_int, old_quit;
+	sigset_t new_mask, old_mask;
+
+	sa.sa_handler = SIG_IGN;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = 0;
+	sigaction(SIGINT, &sa, &old_int);
+	sigaction(SIGQUIT, &sa, &old_quit);
+
+	sigemptyset(&new_mask);
+	sigaddset(&new_mask, SIGCHLD);
+	sigprocmask(SIG_BLOCK, &new_mask, &old_mask);
+
+	if ((pid = fork()) == 0)
+	{
+		sigaction(SIGINT, &old_int, NULL);
+		sigaction(SIGQUIT, &old_quit, NULL);
+		sigprocmask(SIG_SETMASK, &old_mask, NULL);
+		execl("/bin/sh", "sh", "-c", command, (char *)0);
+		_exit(127);
+	}
+
+	if (pid == -1)
+		status = -1;
+	else
+	{
+		while (waitpid(pid, &status, 0) == -1)
+		{
+			if (errno != EINTR)
+			{
+				status = -1;
+				break;
+			}
+		}
+	}
+
+	sigaction(SIGINT, &old_int, NULL);
+	sigaction(SIGQUIT, &old_quit, NULL);
+	sigprocmask(SIG_SETMASK, &old_mask, NULL);
+	return status;
+}
+
 export int ttyslot(void);
 export int unlockpt(int);
 export void *valloc(size_t);