use buffered io to speed output to slow terminals or links

Reference: /n/sources/patch/applied/ndbbio
Date: Wed Mar 19 22:41:14 CET 2008
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/ndb/query.c	Wed Mar 19 22:41:09 2008
+++ /sys/src/cmd/ndb/query.c	Wed Mar 19 22:41:07 2008
@@ -7,6 +7,7 @@
 #include <ndb.h>
 
 static int all, multiple;
+Biobuf bout;
 
 void
 usage(void)
@@ -22,7 +23,7 @@
 {
 	for(; nt; nt = nt->entry)
 		if (strcmp(nt->attr, rattr) == 0)
-			print("%s\n", nt->val);
+			Bprint(&bout, "%s\n", nt->val);
 }
 
 void
@@ -38,7 +39,7 @@
 		if (multiple)
 			prmatch(t, rattr);
 		else if(p)
-			print("%s\n", p);
+			Bprint(&bout, "%s\n", p);
 		ndbfree(t);
 		free(p);
 		return;
@@ -57,8 +58,8 @@
 	/* all entries */
 	for(t = ndbsearch(db, &s, attr, val); t; t = ndbsnext(&s, attr, val)){
 		for(nt = t; nt; nt = nt->entry)
-			print("%s=%s ", nt->attr, nt->val);
-		print("\n");
+			Bprint(&bout, "%s=%s ", nt->attr, nt->val);
+		Bprint(&bout, "\n");
 		ndbfree(t);
 	}
 }
@@ -69,7 +70,7 @@
 	int reps = 1;
 	char *rattr = nil, *dbfile = nil;
 	Ndb *db;
-
+	
 	ARGBEGIN{
 	case 'a':
 		all++;
@@ -78,7 +79,7 @@
 		multiple++;
 		break;
 	case 'f':
-		dbfile = ARGF();
+		dbfile = EARGF(usage());
 		break;
 	default:
 		usage();
@@ -97,7 +98,9 @@
 	default:
 		usage();
 	}
-	
+
+	if(Binit(&bout, 1, OWRITE) == -1)
+		sysfatal("Binit: %r");
 	db = ndbopen(dbfile);
 	if(db == nil){
 		fprint(2, "%s: no db files\n", argv0);