1 files changed, 22 insertions, 0 deletions
diff --git a/lock.c b/lock.c
new file mode 100644
index 0000000..4ac6b40
--- /dev/null
+++ b/lock.c
@@ -0,0 +1,22 @@
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/file.h>
+#include <fcntl.h>
+#include "lock.h"
+
+/**
+	@file lock.c
+	@author djb
+	@source qmail
+	@brief locking of resources
+*/
+
+#ifdef HASFLOCK
+int lock_ex(int fd) { return flock(fd,LOCK_EX); }
+int lock_exnb(int fd) { return flock(fd,LOCK_EX | LOCK_NB); }
+int lock_un(int fd) { return flock(fd,LOCK_UN); }
+#else
+int lock_ex(int fd) { return lockf(fd,1,0); }
+int lock_exnb(int fd) { return lockf(fd,2,0); }
+int lock_un(int fd) { return lockf(fd,0,0); }
+#endif