Yet another du

12e70a36 · Silas Boyd-Wickizer · 3820b87f · 12e70a36 · 12e70a36
--- a/bin/Makefrag
+++ b/bin/Makefrag
@@ -20,9 +20,10 @@ UPROGS= \
 	preadtest \
 	scripttest \
 	ftest \
-	perf
-	# pdu
-	# pls
+	perf \
+	xdu
+# pdu
+# pls

 ifeq ($(HAVE_LWIP),y)
 UPROGS += \

--- a/bin/xdu.cc
+++ b/bin/xdu.cc
+#if defined(LINUX)
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <dirent.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <errno.h>
+#define ST_SIZE(st)  (st).st_size
+#define ST_ISDIR(st) S_ISDIR((st).st_mode)
+#define BSIZ 256
+typedef DIR* dir_t;
+
+static inline int getdent(dir_t d, char *buf, size_t n)
+{
+  struct dirent *entryp, *result;
+  char *dbuf[512];
+  int r;
+
+  entryp = (struct dirent *)dbuf;
+  r = readdir_r(d, entryp, &result);
+  if (r == 0 && result != NULL) {
+    strcpy(buf, entryp->d_name);
+    return 0;
+  }
+  return -1;
+}
+
+#else // assume xv6
+
+#include "types.h"
+#include "stat.h"
+#include "user.h"
+#include "fs.h"
+#define ST_SIZE(st)  (st).size
+#define ST_ISDIR(st) ((st).type == T_DIR)
+#define stderr 2
+#define BSIZ (DIRSIZ+1)
+typedef int dir_t;
+
+static inline dir_t 
+fdopendir(int fd) {
+  return fd;
+}
+
+static inline void
+closedir(dir_t d) {
+
+}
+
+static inline int 
+getdent(dir_t fd, char *buf, size_t n)
+{
+  struct dirent de;
+  int r; 
+
+again:
+  r = read(fd, &de, sizeof(de));
+  if (r == sizeof(de)) {
+    if (de.inum == 0)
+      goto again;
+
+    memmove(buf, de.name, n-1);
+    buf[n-1] = 0;
+    return 0;
+  }
+
+  return -1;
+}
+#endif
+
+static int
+du(int fd)
+{
+  struct stat st;
+  if (fstat(fd, &st) < 0) {
+    fprintf(stderr, "du: cannot stat\n");
+    close(fd);
+    return 0;
+  }
+
+  int size = ST_SIZE(st);
+  if (ST_ISDIR(st)) {
+    char buf[BSIZ];
+    dir_t d = fdopendir(fd);
+    while (getdent(d, buf, BSIZ) == 0) {
+      if (!strcmp(buf, ".") || !strcmp(buf, ".."))
+        continue;
+
+      int nfd = openat(fd, buf, 0);
+      if (nfd >= 0)
+        size += du(nfd);  // should go into work queue
+    }
+    closedir(d);
+  }
+
+  close(fd);
+  return size;
+}
+
+int
+main(int ac, char **av)
+{
+  printf("%d\n", du(open(".", 0)));
+  return 0;
+}