X-Git-Url: https://pd.if.org/git/?p=zos;a=blobdiff_plain;f=klib%2Fstrncpy.c;fp=klib%2Fstrncpy.c;h=e67442000b18406475b1b05639db423bdca342c6;hp=0000000000000000000000000000000000000000;hb=5c0e560e481e2e97b793f7574e849a5882781df9;hpb=e57b692bd3a86ee40fd89416a06fd696f1ff3bf9

diff --git a/klib/strncpy.c b/klib/strncpy.c
new file mode 100644
index 0000000..e674420
--- /dev/null
+++ b/klib/strncpy.c
@@ -0,0 +1,17 @@
+#include <string.h>
+
+char *strncpy(char *s1, const char *s2, size_t n) {
+	char * rc = s1;
+	while ( (n > 0) && (*s1++ = *s2++) ) {
+		/* Cannot do "n--" in the conditional as size_t is unsigned and we have
+		 * to check it again for >0 in the next loop below, so we must not risk
+		 * underflow.
+		 */
+		--n;
+	}
+	/* Checking against 1 as we missed the last --n in the loop above. */
+	while (n-- > 1) {
+		*s1++ = '\0';
+	}
+	return rc;
+}