[PATCH 30/42] tools/nolibc/string: add strncpy() and strlcpy()

From: Willy Tarreau
Date: Mon Feb 07 2022 - 11:34:01 EST


These are minimal variants. strncpy() always fills the destination for
<size> chars, while strlcpy() copies no more than <size> including the
zero and returns the source's length. The respective sizes on various
archs are:

strncpy(): x86:0x1f mips:0x30 arm:0x20
strlcpy(): x86:0x17 mips:0x34 arm:0x1a

Signed-off-by: Willy Tarreau <w@xxxxxx>
---
tools/include/nolibc/string.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index b831a02de83f..7c274efcdfae 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -121,6 +121,34 @@ size_t nolibc_strlen(const char *str)
nolibc_strlen((str)); \
})

+static __attribute__((unused))
+size_t strlcpy(char *dst, const char *src, size_t size)
+{
+ size_t len;
+ char c;
+
+ for (len = 0;;) {
+ c = src[len];
+ if (len < size)
+ dst[len] = c;
+ if (!c)
+ break;
+ len++;
+ }
+ return len;
+}
+
+static __attribute__((unused))
+char *strncpy(char *dst, const char *src, size_t size)
+{
+ size_t len;
+
+ for (len = 0; len < size; len++)
+ if ((dst[len] = *src))
+ src++;
+ return dst;
+}
+
static __attribute__((unused))
char *strrchr(const char *s, int c)
{
--
2.35.1