--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/seq.c	Sat May 17 17:54:21 2008 -0500
@@ -0,0 +1,47 @@
+/* vi: set sw=4 ts=4:
+ *
+ * seq.c - Count from first to last, by increment.
+ *
+ * Copyright 2006 Rob Landley <rob@landley.net>
+ *
+ * Not in SUSv3.  (Don't ask me why not.)
+
+USE_SEQ(NEWTOY(seq, "<1>3?+", TOYFLAG_USR|TOYFLAG_BIN))
+
+config SEQ
+	bool "seq"
+	default y
+	help
+	  usage: seq [first] [increment] last
+
+	  Count from first to last, by increment.  Omitted arguments default
+	  to 1.  Two arguments are used as first and last.  Arguments can be
+	  negative or floating point.
+*/
+
+#include "toys.h"
+
+void seq_main(void)
+{
+	double first, increment, last, dd;
+
+	// Parse command line arguments, with appropriate defaults.
+	// Note that any non-numeric arguments are treated as zero.
+	first = increment = 1;
+	switch (toys.optc) {
+		case 3:
+			increment = atof(toys.optargs[1]);
+		case 2:
+			first = atof(*toys.optargs);
+		default:
+			last = atof(toys.optargs[toys.optc-1]);
+	}
+
+	// Yes, we're looping on a double.  Yes rounding errors can accumulate if
+	// you use a non-integer increment.  Deal with it.
+	for (dd=first; (increment>0 && dd<=last) || (increment <0 && dd>=last);
+		dd+=increment)
+	{
+		printf("%g\n", dd);
+	}
+}