9os

commit 8e03e0ea337ea4eca6c8d905062bbacb6dffb9c3
parent 6c9f8d77183b91462388bc44572c858b642ea19b
Author: Roberto Vargas <roberto.vargas@arm.com>
Date:   Thu,  9 May 2019 13:39:00 +0100

[libc] Add memrchr function

Change-Id: Ic61a133b66888896711a326f17d6adec2076c478

Diffstat:
M
src/libc/string/Makefile
 | 
1
+
A
src/libc/string/memrchr.c
 | 
13
+++++++++++++

2 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/src/libc/string/Makefile b/src/libc/string/Makefile
@@ -4,6 +4,7 @@ include $(PROJECTDIR)/scripts/rules.mk
 include ../rules.mk
 
 OBJS = memchr.o\
+       memrchr.o \
        memcmp.o\
        memcpy.o\
        memmove.o\
diff --git a/src/libc/string/memrchr.c b/src/libc/string/memrchr.c
@@ -0,0 +1,13 @@
+#include <string.h>
+
+#undef memrchr
+
+void *
+memrchr(const void *s, int c, size_t n)
+{
+	unsigned char *p = s;
+
+	for (p += n-1; n > 0 && *p != c; --p)
+		n--;
+	return (n == 0) ? NULL : p;
+}