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Diffstat (limited to 'src/libs6/s6lockd_openandlock.c')
-rw-r--r--src/libs6/s6lockd_openandlock.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/src/libs6/s6lockd_openandlock.c b/src/libs6/s6lockd_openandlock.c
new file mode 100644
index 0000000..42c3ca6
--- /dev/null
+++ b/src/libs6/s6lockd_openandlock.c
@@ -0,0 +1,35 @@
+/* ISC license. */
+
+#include <errno.h>
+
+#include <skalibs/strerr2.h>
+#include <skalibs/djbunix.h>
+
+#include "s6lockd.h"
+
+int s6lockd_openandlock (char const *file, int ex, int nb)
+{
+ int fd, r ;
+ if (ex)
+ {
+ fd = open_create(file) ;
+ if (fd < 0) strerr_diefu3sys(111, "open ", file, " for writing") ;
+ }
+ else
+ {
+ fd = open_read(file) ;
+ if (fd < 0)
+ {
+ if (errno != ENOENT) strerr_diefu3sys(111, "open ", file, " for reading") ;
+ fd = open_create(file) ;
+ if (fd < 0) strerr_diefu2sys(111, "create ", file) ;
+ fd_close(fd) ;
+ fd = open_read(file) ;
+ if (fd < 0) strerr_diefu3sys(111, "open ", file, " for reading") ;
+ }
+ }
+ r = fd_lock(fd, ex, nb) ;
+ if (!r) errno = EBUSY ;
+ if (r < 1) strerr_diefu2sys(1, "lock ", file) ;
+ return fd ;
+}