Expose low-level opendir/readdir dir traversal.

* stream.c (UTF_DECL_OPENDIR): Macro defined, to enable
w_opendir declaration in utf8.h.
(w_opendir): Static function removed.

* sysif.c (UTF_DECL_OPENDIR): Macro defined.
(dir_s): Symbol defined unconditionally now, regardless of
HAVE_PWUID.
(dirent_s): New symbol.
(dirent_st): New static variable.
(struct dir): New struct type.
(opendir_free, opendir_mark opendir_wrap, readdir_wrap): New
static functions.
(opendir_ops): New static structure.
(sysif_init): Intern dirent symbol. Create dirent structure
type. Register opendir and readdir intrinsic functions.
Register variables dt-blk, dt-chr, dt-dir, dt-fifo, dt-lnk,
dt-reg, dt-sock and dt-unknown.

* utf8.c (UTF8_DECL_OPENDIR): Macro defined.
(w_opendir): Function moved here from stream.c, and turned
external.

* utf8.h (w_opendir): Declared, conditionally on
UTF8_DECL_OPENDIR being defined, so that most modules that
include utf8.h don't have to include <dirent.h>.

* txr.1: Documented.

diff --git a/sysif.c b/sysif.c

1 files changed, 10 insertions, 0 deletions

diff --git a/utf8.c b/utf8.c
index 2760c718..39d1e1c4 100644
--- a/utf8.c
+++ b/utf8.c
@@ -25,11 +25,13 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#define UTF8_DECL_OPENDIR
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <wchar.h>
 #include <signal.h>
+#include <dirent.h>
 #include "config.h"
 #include "lib.h"
 #include "signal.h"
@@ -415,3 +417,11 @@ int w_rename(const wchar_t *wfrom, const wchar_t *wto)
   free(from);
   return err;
 }
+
+DIR *w_opendir(const wchar_t *wname)
+{
+  char *name = utf8_dup_to(wname);
+  DIR *d = opendir(name);
+  free(name);
+  return d;
+}