1 files changed, 60 insertions, 0 deletions
diff --git a/memptolower.c b/memptolower.c
new file mode 100644
index 0000000..de813e5
--- /dev/null
+++ b/memptolower.c
@@ -0,0 +1,60 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsimple.h"
+#ifndef TEST
+
+
+void *
+libsimple_memptolower(void *d_, const void *s_, size_t n) /* TODO man */
+{
+	char *ret, *d = d_;
+	const char *s = s_;
+	if (d == s) {
+		for (; n; d++, n--)
+			*d = tolower(*d);
+		return d;
+	} else if (d < s) {
+		for (; n; d++, s++, n--)
+			*d = tolower(*s);
+		return d;
+	} else {
+		ret = &d[n];
+		while (n) {
+			n--;
+			d[n] = tolower(s[n]);
+		}
+		return ret;
+	}
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void)
+{
+	char buf[100];
+
+	stpcpy(buf, "ABCDEabcde12345");
+	assert(libsimple_memptolower(&buf[3], &buf[0], 16) == &buf[19]);
+	assert(!strcmp(buf, "ABCabcdeabcde12345"));
+	stpcpy(buf, "ABCDEabcde12345");
+	assert(libsimple_memptolower(&buf[0], &buf[3], 13) == &buf[13]);
+	assert(!strcmp(buf, "deabcde12345"));
+	stpcpy(buf, "ABCDEabcde12345");
+	assert(libsimple_memptolower(&buf[0], &buf[0], 16) == &buf[16]);
+	assert(!strcmp(buf, "abcdeabcde12345"));
+	stpcpy(buf, "ABCDEabcde12345");
+	assert(!strcmpnul(libsimple_memtolower(&buf[3], &buf[0], 16), "abcdeabcde12345"));
+	assert(!strcmp(buf, "ABCabcdeabcde12345"));
+	stpcpy(buf, "ABCDEabcde12345");
+	assert(!strcmpnul(libsimple_memtolower(&buf[0], &buf[3], 13), "deabcde12345"));
+	assert(!strcmp(buf, "deabcde12345"));
+	stpcpy(buf, "ABCDEabcde12345");
+	assert(!strcmpnul(libsimple_memtolower(&buf[0], &buf[0], 16), "abcdeabcde12345"));
+	assert(!strcmp(buf, "abcdeabcde12345"));
+
+	return 0;
+}
+
+#endif