1 files changed, 23 insertions, 0 deletions
diff --git a/src/libbbsutil/lock.c b/src/libbbsutil/lock.c
new file mode 100644
index 00000000..4b28bab1
--- /dev/null
+++ b/src/libbbsutil/lock.c
@@ -0,0 +1,23 @@
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+/**
+ * lock fd
+ * @param mode	F_WRLCK, F_UNLCK
+ */
+void
+PttLock(int fd, int start, int size, int mode)
+{
+    static struct flock lock_it;
+    int             ret;
+
+    lock_it.l_whence = SEEK_CUR;/* from current point */
+    lock_it.l_start = start;	/* -"- */
+    lock_it.l_len = size;	/* length of data */
+    lock_it.l_type = mode;	/* set exclusive/write lock */
+    lock_it.l_pid = 0;		/* pid not actually interesting */
+    while ((ret = fcntl(fd, F_SETLKW, &lock_it)) < 0 && errno == EINTR)
+      sleep(1);
+}
+