Add _Fork(2).

libc/Makefile

@@ -702,6 +702,7 @@ unistd/fchownat.o \
 unistd/fchown.o \
 unistd/fchrootat.o \
 unistd/fchroot.o \
+unistd/_Fork.o \
 unistd/fork.o \
 unistd/fpathconf.o \
 unistd/fsync.o \

libc/include/unistd.h

@@ -533,6 +533,7 @@ int unlinkat(int, const char*, int);
 
 /* Functions from POSIX 2024. */
 #if __USE_SORTIX || 202405L <= __USE_POSIX
+pid_t _Fork(void);
 int dup3(int, int, int);
 int getentropy(void*, size_t);
 int pipe2(int [2], int);

libc/unistd/_Fork.c

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2011, 2012, 2024 Jonas 'Sortie' Termansen.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * unistd/_Fork.c
+ * Create a new task inheriting some properties from the current task.
+ */
+
+#include <unistd.h>
+
+pid_t _Fork(void)
+{
+	return sfork(SFFORK);
+}

libc/unistd/fork.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2011, 2012, 2024 Jonas 'Sortie' Termansen.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -21,5 +21,5 @@
 
 pid_t fork(void)
 {
-	return sfork(SFFORK);
+	return _Fork();
 }