fcntl-h, etc.: prefer O_SEARCH to O_RDONLY when applicable POSIX 2008 specifies a new 'open' flag O_SEARCH, which can be used when one needs search access to a directory but not read access. On systems where it is available, it works in some cases where O_RDONLY does not, namely on directories that are searchable but not readable, and which need only to be searchable. If O_SEARCH is not available, fall back to the traditional method of using O_RDONLY. * lib/fcntl.in.h (O_SEARCH): #define to O_RDONLY if not defined. * lib/chdir-long.c (cdb_advance_fd): Use O_SEARCH, not O_RDONLY, when opening a directory that needs only to be searchable. * lib/chdir-safer.c (chdir_no_follow): Likewise. * lib/fts.c (diropen, fts_open, fd_ring_check): Likewise. * lib/openat-proc.c (openat_proc_name): Likewise. * lib/openat.c (openat_needs_fchdir): Likewise. * lib/save-cwd.c (save_cwd): Likewise. * lib/savewd.c (savewd_save, savewd_chdir): Likewise.

--- a/lib/fcntl.in.h
+++ b/lib/fcntl.in.h
@@ -210,6 +210,10 @@
 # define O_RSYNC 0
 #endif
 
+#ifndef O_SEARCH
+# define O_SEARCH O_RDONLY /* This is often close enough in older systems.  */
+#endif
+
 #ifndef O_SYNC
 # define O_SYNC 0
 #endif