diff --git a/sys/src/cmd/p.c b/sys/src/cmd/p.c
index 9bc5cc471..4b3a713e3 100644
--- a/sys/src/cmd/p.c
+++ b/sys/src/cmd/p.c
@@ -21,7 +21,9 @@ main(int argc, char *argv[])
 		fprint(2, "p: can't open /dev/cons\n");
 		exits("missing /dev/cons");
 	}
+	Blethal(cons, nil);
 	Binit(&bout, 1, OWRITE);
+	Blethal(&bout, nil);
 	n = 0;
 	while(argc > 1) {
 		--argc; argv++;
@@ -54,6 +56,7 @@ printfile(int f)
 
 	b = malloc(sizeof(Biobuf));
 	Binit(b, f, OREAD);
+	Blethal(b, nil);
 	for(;;){
 		for(i=1; i <= pglen; i++) {
 			s = Brdline(b, '\n');
diff --git a/sys/src/cmd/pr.c b/sys/src/cmd/pr.c
index 2aff9ab43..1c5b75acf 100644
--- a/sys/src/cmd/pr.c
+++ b/sys/src/cmd/pr.c
@@ -147,6 +147,7 @@ main(int argc, char *argv[])
 	int nfdone = 0;
 
 	Binit(&bout, 1, OWRITE);
+	Blethal(&bout, nil);
 	Files = fstr;
 	for(argc = findopt(argc, argv); argc > 0; --argc, ++argv)
 		if(Multi == 'm') {
@@ -600,6 +601,7 @@ mustopen(char *s, Fils *f)
 		if(f->f_f == 0)
 			cerror("no memory");
 		Binit(f->f_f, 0, OREAD);
+		Blethal(f->f_f, nil);
 	} else
 	if((f->f_f = Bopen(f->f_name = s, OREAD)) == 0) {
 		tmp = ffiler(f->f_name);
@@ -607,6 +609,7 @@ mustopen(char *s, Fils *f)
 		free(tmp);
 	}
 	if(f->f_f != 0) {
+		Blethal(f->f_f, nil);
 		if((f->f_nextc = Bgetrune(f->f_f)) >= 0 || Multi == 'm')
 			return f->f_f;
 		sprint(s = (char*)getspace(strlen(f->f_name) + 1 + EMPTY),
diff --git a/sys/src/cmd/sed.c b/sys/src/cmd/sed.c
index 4fd08b8b5..aa603b4bd 100644
--- a/sys/src/cmd/sed.c
+++ b/sys/src/cmd/sed.c
@@ -207,6 +207,7 @@ main(int argc, char **argv)
 
 	lnum = 0;
 	Binit(&fout, 1, OWRITE);
+	Blethal(&fout, nil);
 	fcode[nfiles++] = &fout;
 	compfl = 0;
 
@@ -610,6 +611,7 @@ open_file(char *name)
 	    (fd = create(name, OWRITE, 0666)) < 0)
 		quit("Cannot create %s", name);
 	Binit(bp, fd, OWRITE);
+	Blethal(bp, nil);
 	Bseek(bp, 0, 2);
 	fcode[nfiles++] = bp;
 	return bp;
@@ -688,6 +690,7 @@ newfile(enum PTYPE type, char *name)
 		prog.curr = name;
 	else if ((prog.bp = Bopen(name, OREAD)) == 0)
 		quit("Cannot open pattern-file: %s\n", name);
+	Blethal(prog.bp, nil);
 	prog.type = type;
 }
 
@@ -1347,6 +1350,7 @@ arout(void)
 			*s = '\0';
 			if((fi = Bopen(buf, OREAD)) == 0)
 				continue;
+			Blethal(fi, nil);
 			while((c = Bgetc(fi)) >= 0)
 				Bputc(&fout, c);
 			Bterm(fi);
@@ -1450,6 +1454,7 @@ opendata(void)
 		Binit(&stdin, 0, OREAD);
 		f = &stdin;
 	}
+	Blethal(f, nil);
 	fhead = fhead->next;
 	return 1;
 }
diff --git a/sys/src/cmd/xd.c b/sys/src/cmd/xd.c
index dcbc2f2f9..e14b741e1 100644
--- a/sys/src/cmd/xd.c
+++ b/sys/src/cmd/xd.c
@@ -65,6 +65,7 @@ main(int argc, char *argv[])
 	Arg *ap;
 
 	Binit(&bout, 1, OWRITE);
+	Blethal(&bout, nil);
 	err = 0;
 	ap = 0;
 	while(argc>1 && argv[1][0]=='-' && argv[1][1]){
@@ -205,6 +206,7 @@ xd(char *name, int title)
 		bp = &bin;
 		Binit(bp, fd, OREAD);
 	}
+	Blethal(bp, nil);
 	if(title)
 		xprint("%s\n", name);
 	addr = 0;
diff --git a/sys/src/cmd/yacc.c b/sys/src/cmd/yacc.c
index 75e0d0161..7aef1a281 100644
--- a/sys/src/cmd/yacc.c
+++ b/sys/src/cmd/yacc.c
@@ -402,6 +402,7 @@ others(void)
 	finput = Bopen(parser, OREAD);
 	if(finput == 0)
 		error("cannot find parser %s", parser);
+	Blethal(finput, nil);
 	warray("yyr1", levprd, nprod);
 	aryfil(temp1, nprod, 0);
 	PLOOP(1, i)
@@ -481,6 +482,7 @@ others(void)
 				faction = Bopen(actname, OREAD);
 				if(faction == 0)
 					error("cannot reopen action tempfile");
+				Blethal(faction, nil);
 				while((c=Bgetrune(faction)) != Beof)
 					Bputrune(ftable, c);
 				Bterm(faction);
@@ -1217,6 +1219,8 @@ setup(int argc, char *argv[])
 	faction = Bopen(actname = mktemp(tactname), OWRITE);
 	if(ftemp == 0 || faction == 0)
 		error("cannot open temp file");
+	Blethal(ftemp, nil);
+	Blethal(faction, nil);
 	if(argc < 1)
 		error("no input file");
 	infile = argv[0];
@@ -1232,6 +1236,7 @@ setup(int argc, char *argv[])
 	finput = Bopen(infile, OREAD);
 	if(finput == 0)
 		error("cannot open '%s'", argv[0]);
+	Blethal(finput, nil);
 	cnamp = cnames;
 
 	defin(0, "$end");
@@ -2127,6 +2132,7 @@ openup(char *stem, int dflag, int vflag, int ytab, char *ytabc)
 		foutput = Bopen(buf, OWRITE);
 		if(foutput == 0)
 			error("cannot open %s", buf);
+		Blethal(foutput, nil);
 	}
 	if(yydebug) {
 		snprint(buf, sizeof buf, "%s.%s", stem, FILEDEBUG);
@@ -2138,6 +2144,7 @@ openup(char *stem, int dflag, int vflag, int ytab, char *ytabc)
 		fdefine = Bopen(buf, OWRITE);
 		if(fdefine == 0)
 			error("can't create %s", buf);
+		Blethal(fdefine, nil);
 	}
 	if(ytab == 0)
 		snprint(buf, sizeof buf, "%s.%s", stem, OFILE);
@@ -2146,6 +2153,7 @@ openup(char *stem, int dflag, int vflag, int ytab, char *ytabc)
 	ftable = Bopen(buf, OWRITE);
 	if(ftable == 0)
 		error("cannot open table file %s", buf);
+	Blethal(ftable, nil);
 }
 
 /*
@@ -2619,6 +2627,7 @@ callopt(void)
 	finput = Bopen(tempname, OREAD);
 	if(finput == 0)
 		error("optimizer cannot open tempfile");
+	Blethal(finput, nil);
 
 	pgo[0] = 0;
 	temp1[0] = 0;