--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/uprogs/wc.c	Sun Jan 06 19:27:03 2019 +0900
@@ -0,0 +1,54 @@
+#include "types.h"
+#include "stat.h"
+#include "user.h"
+
+char buf[512];
+
+void
+wc(int fd, char *name)
+{
+  int i, n;
+  int l, w, c, inword;
+
+  l = w = c = 0;
+  inword = 0;
+  while((n = read(fd, buf, sizeof(buf))) > 0){
+    for(i=0; i<n; i++){
+      c++;
+      if(buf[i] == '\n')
+        l++;
+      if(strchr(" \r\t\n\v", buf[i]))
+        inword = 0;
+      else if(!inword){
+        w++;
+        inword = 1;
+      }
+    }
+  }
+  if(n < 0){
+    printf(1, "wc: read error\n");
+    exit();
+  }
+  printf(1, "%d %d %d %s\n", l, w, c, name);
+}
+
+int
+main(int argc, char *argv[])
+{
+  int fd, i;
+
+  if(argc <= 1){
+    wc(0, "");
+    exit();
+  }
+
+  for(i = 1; i < argc; i++){
+    if((fd = open(argv[i], 0)) < 0){
+      printf(1, "wc: cannot open %s\n", argv[i]);
+      exit();
+    }
+    wc(fd, argv[i]);
+    close(fd);
+  }
+  exit();
+}