Refactor _at functions, add symlink_at

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/src/libunixonacid/emulate_at.c b/src/libunixonacid/emulate_at.c
new file mode 100644
index 0000000..0bb194a
--- /dev/null
+++ b/src/libunixonacid/emulate_at.c
@@ -0,0 +1,43 @@
+/* ISC license. */
+
+#include <skalibs/sysdeps.h>
+
+#if !defined(SKALIBS_HASOPENAT) || !defined(SKALIBS_HASLINKAT)
+
+#include <skalibs/bsdsnowflake.h>
+
+#include <errno.h>
+
+#include <skalibs/functypes.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/unix-transactional.h>
+#include "at-internal.h"
+
+int emulate_at (int dirfd, init_func_ref f, deinit_func_ref g, void *p)
+{
+  int r ;
+  int fdhere = open_read(".") ;
+  if (fdhere < 0) return -1 ;
+  if (fd_chdir(dirfd) < 0) goto errclose ;
+  r = (*f)(p) ;
+  if (r < 0)
+  {
+    int e = errno ;
+    fd_chdir(fdhere) ;
+    errno = e ;
+    goto errclose ;
+  }
+  if (fd_chdir(fdhere) < 0)
+  {
+    (*g)(r, p) ;
+    goto errclose ;
+  }
+  fd_close(fdhere) ;
+  return r ;
+
+ errclose:
+  fd_close(fdhere) ;
+  return -1 ;
+}
+
+#endif