Adding the yes(1) command.

Makefile

@@ -52,7 +52,8 @@ SRC = \
 	tty.c      \
 	uname.c    \
 	seq.c      \
-	wc.c
+	wc.c       \
+	yes.c
 
 OBJ = $(SRC:.c=.o) $(LIB)
 BIN = $(SRC:.c=)

TODO

@@ -60,4 +60,3 @@ unlink file
 
 who 
 
-yes [string]

yes.1

@@ -0,0 +1,10 @@
+.TH YES 1 sbase\-VERSION
+.SH NAME
+yes \- output a string repeatedly 
+.SH SYNOPSIS
+.B yes 
+.RB [ string ... ]
+.SH DESCRIPTION
+.B yes 
+will repeatedly output 'y' or the strings specified.
+

yes.c

@@ -0,0 +1,44 @@
+/* See LICENSE file for copyright and license details. */
+#include <unistd.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "arg.h"
+#include "util.h"
+
+char *argv0;
+
+void
+usage(void)
+{
+	eprintf("usage: %s [string ...]\n", basename(argv0));
+}
+
+int
+main(int argc, char *argv[])
+{
+	int i;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND;
+
+	if (!argc) {
+		for(;;)
+			puts("y");
+	}
+
+	for (;;) {
+		for (i = 0; i < argc; i++) {
+			fputs(argv[i], stdout);
+			if (argv[i+1] != NULL)
+				fputs(" ", stdout);
+		}
+		fputs("\n", stdout);
+	}
+
+	return EXIT_SUCCESS;
+}
+