1 files changed, 68 insertions, 0 deletions
diff --git a/src/vu-next-frame.c b/src/vu-next-frame.c
new file mode 100644
index 0000000..0e693c4
--- /dev/null
+++ b/src/vu-next-frame.c
@@ -0,0 +1,68 @@
+/* See LICENSE file for copyright and license details. */
+#include "arg.h"
+#include "util.h"
+
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define eprintf(...) enprintf(2, __VA_ARGS__)
+
+static void
+usage(void)
+{
+	eprintf("usage: %s -w width -h height\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	size_t width = 0, height = 0;
+	size_t p, n, w, max;
+	ssize_t r;
+	char buf[8096];
+	int anything = 0;
+
+	ARGBEGIN {
+	case 'w':
+		if (tozu(EARGF(usage()), 1, SIZE_MAX, &width))
+			eprintf("argument of -w must be an integer in [1, %zu]\n", SIZE_MAX);
+		break;
+	case 'h':
+		if (tozu(EARGF(usage()), 1, SIZE_MAX, &height))
+			eprintf("argument of -h must be an integer in [1, %zu]\n", SIZE_MAX);
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (!width || !height || argc)
+		usage();
+
+	while (height) {
+		height--;
+		for (w = width << 2; w;) {
+			max = sizeof(buf) < w ? sizeof(buf) : w;
+			r = read(STDIN_FILENO, buf, max);
+			if (r < 0)
+				eprintf("read <stdin>:");
+			if (r == 0)
+				goto done;
+			anything = 1;
+			w -= n = (size_t)r;
+			for (p = 0; p < n;) {
+				r = write(STDOUT_FILENO, buf + p, n - p);
+				if (r < 0)
+					eprintf("write <stdin>:");
+				p += (size_t)r;
+			}
+		}
+	}
+done:
+
+	if (height || w)
+		eprintf("incomplete frame\n");
+
+	return !anything;
+}