1 files changed, 60 insertions, 0 deletions
diff --git a/src/libunixonacid/open3_at.c b/src/libunixonacid/open3_at.c
new file mode 100644
index 0000000..d9c7222
--- /dev/null
+++ b/src/libunixonacid/open3_at.c
@@ -0,0 +1,60 @@
+/* ISC license. */
+
+#include <skalibs/sysdeps.h>
+
+#ifdef SKALIBS_HASOPENAT
+
+#ifndef _ATFILE_SOURCE
+#define _ATFILE_SOURCE
+#endif
+
+#include <skalibs/nonposix.h>
+#include <fcntl.h>
+#include <skalibs/unix-transactional.h>
+
+int open3_at (int dirfd, char const *file, int flags, unsigned int mode)
+{
+  return openat(dirfd, file, flags, mode) ;
+}
+
+#else
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/unix-transactional.h>
+
+int open3_at (int dirfd, char const *file, int flags, unsigned int mode)
+{
+  int fd ;
+  int fdhere = open_read(".") ;
+  if (fdhere < 0) return -1 ;
+  if (fd_chdir(dirfd) < 0)
+  {
+    register int e = errno ;
+    fd_close(fdhere) ;
+    errno = e ;
+    return -1 ;
+  }
+  fd = open3(file, flags, mode) ;
+  if (fd < 0)
+  {
+    register int e = errno ;
+    fd_chdir(fdhere) ;
+    fd_close(fdhere) ;
+    errno = e ;
+    return -1 ;
+  }
+  if (fd_chdir(fdhere) < 0)
+  {
+    register int e = errno ;
+    fd_close(fdhere) ;
+    errno = e ;
+    return -1 ;
+  }
+  return fd ;
+}
+
+#endif