1 files changed, 20 insertions, 0 deletions
diff --git a/src/libs6f/s6f_lock.c b/src/libs6f/s6f_lock.c
new file mode 100644
index 0000000..1ef1718
--- /dev/null
+++ b/src/libs6f/s6f_lock.c
@@ -0,0 +1,20 @@
+/* ISC license. */
+
+#include <string.h>
+
+#include <skalibs/strerr.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/unix-transactional.h>
+
+#include "s6f.h"
+
+int s6f_lock (char const *stmpdir, int w)
+{
+  int fdstmp = s6f_confdir_open(stmpdir, 1) ;
+  int fd = openc_truncat(fdstmp, "lock") ;
+  if (fd == -1) strerr_diefu4sys(111, "open ", stmpdir, "/lock", " for writing") ;
+  fd_close(fdstmp) ;
+  if (fd_lock(fd, w, 0) < 1)
+    strerr_diefu3sys(111, "lock ", stmpdir, "/lock") ;
+  return fd ;
+}