1 files changed, 55 insertions, 0 deletions
diff --git a/src/cmd/tests/shared/printf.c b/src/cmd/tests/shared/printf.c
new file mode 100644
index 0000000..d8df48a
--- /dev/null
+++ b/src/cmd/tests/shared/printf.c
@@ -0,0 +1,55 @@
+#include "../tests.h"
+#include <stdio.h>
+#include <string.h>
+
+#pragma GCC diagnostic ignored "-Wformat-truncation"
+
+static void test_printf(void) {
+	char buf[64];
+	memset(buf, '?', 64);
+
+	/* test proper overflow handling in snprintf */
+	test(13 == snprintf(buf, 15, "That's 0x%x", 0x1337));
+	test(!memcmp(buf, "That's 0x1337\0??", 16));
+	test(17 == snprintf(buf, 15, "%05x %05x %05x", 0, 0, 0));
+	test(!memcmp(buf, "00000 00000 00\0?", 16));
+
+	/* all the other stuff */
+	snprintf(buf, sizeof buf, "%010x", 0x1BABE);
+	test(!strcmp(buf, "000001babe"));
+	snprintf(buf, sizeof buf, "%10x", 0x1BABE);
+	test(!strcmp(buf, "     1babe"));
+	snprintf(buf, sizeof buf, "%10s", "hello");
+	test(!strcmp(buf, "     hello"));
+
+	snprintf(buf, sizeof buf, "%s%%%s", "ab", "cd");
+	test(!strcmp(buf, "ab%cd"));
+
+	snprintf(buf, sizeof buf, "%05u,%05u", 1234, 56789);
+	test(!strcmp(buf, "01234,56789"));
+
+	snprintf(buf, sizeof buf, "%5d,%5d", 123, 4567);
+	test(!strcmp(buf, "  123, 4567"));
+	snprintf(buf, sizeof buf, "%5d,%5d", -123, -4567);
+	test(!strcmp(buf, " -123,-4567"));
+
+	snprintf(buf, sizeof buf, "%u,%d,%x", 0, 0, 0);
+	test(!strcmp(buf, "0,0,0"));
+
+	/* precision */
+	snprintf(buf, sizeof buf, "%5.2u,%5.2d,%5.2x", 0, 0, 0);
+	test(!strcmp(buf, "   00,   00,   00"));
+	snprintf(buf, sizeof buf, "%5.2u,%5.2d,%5.2x", 10, -10, 0x10);
+	test(!strcmp(buf, "   10,  -10,   10"));
+	snprintf(buf, sizeof buf, "%5.3d", -1);
+	test(!strcmp(buf, " -001"));
+	snprintf(buf, sizeof buf, "%.5d", 123);
+	test(!strcmp(buf, "00123"));
+
+	snprintf(buf, sizeof buf, "%.1s,%.10s,%.*s", "hello", "hello", 3, "hello");
+	test(!strcmp(buf, "h,hello,hel"));
+}
+
+void r_s_printf(void) {
+	run_test(test_printf);
+}