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Subject[PATCH 4/8] tools/nolibc/string: add strcmp() and strncmp()
Date
We need these functions all the time, including when checking environment
variables and parsing command-line arguments. These implementations were
optimized to show optimal code size on a wide range of compilers (22 bytes
return included for strcmp(), 33 for strncmp()).

Signed-off-by: Willy Tarreau <w@1wt.eu>
---
tools/include/nolibc/string.h | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index 4554b6fcb400..0d5e870c7c0b 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -102,6 +102,17 @@ char *strchr(const char *s, int c)
return NULL;
}

+static __attribute__((unused))
+int strcmp(const char *a, const char *b)
+{
+ unsigned int c;
+ int diff;
+
+ while (!(diff = (unsigned char)*a++ - (c = (unsigned char)*b++)) && c)
+ ;
+ return diff;
+}
+
static __attribute__((unused))
char *strcpy(char *dst, const char *src)
{
@@ -184,6 +195,18 @@ char *strncat(char *dst, const char *src, size_t size)
return orig;
}

+static __attribute__((unused))
+int strncmp(const char *a, const char *b, size_t size)
+{
+ unsigned int c;
+ int diff = 0;
+
+ while (size-- &&
+ !(diff = (unsigned char)*a++ - (c = (unsigned char)*b++)) && c)
+ ;
+
+ return diff;
+}

static __attribute__((unused))
char *strncpy(char *dst, const char *src, size_t size)
--
2.35.1
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