Add strnkcpy() and strnkcat(). These are similar to strlcpy and strlcat,

but simply return a bool indicating whether the destination received
a truncated copy of the source (true if truncation occurs else false).

The change in return value semantics allows these functions to stop
scanning the source string early when truncation occurs, stopping the
program from scanning a possibly arbitrary-length source string.

I rarely use these return values in my own programs, so it won't be
very hard to bulk convert with no risk of regressions.

Further, the different namespace allows me to not depend on the presence
or absence of strlc(py|at) in the standard libraries.

ncmlib/chroot.c

@@ -53,7 +53,7 @@ int chroot_enabled(void)
 
 void update_chroot(const char *path)
 {
-	strlcpy(chrootd, path, sizeof chrootd);
+	strnkcpy(chrootd, path, sizeof chrootd);
 	chroot_modified = 1;
 }
 

ncmlib/strl.c

@@ -30,6 +30,27 @@
 #include <unistd.h>
 #include "strl.h"
 
+// true == truncated, false == no truncation
+bool strnkcpy (char *dest, const char *src, size_t size)
+{
+	if (size > 0) {
+		size_t i = 0;
+		size--;
+		for (; size > 0 && src[i] != '\0'; ++i, size--)
+			dest[i] = src[i];
+		dest[i] = '\0';
+		return size ? false : true;
+	} else
+		return true;
+}
+
+// true == truncated, false == no truncation
+bool strnkcat (char *dest, const char *src, size_t size)
+{
+	for (; size > 0 && *dest != '\0'; size--, dest++);
+	return strnkcpy(dest, src, size);
+}
+
 #ifndef HAVE_STRLCPY
 size_t strlcpy (char *dest, const char *src, size_t size)
 {

ncmlib/strl.h

@@ -30,6 +30,11 @@
 #ifndef NCM_STRL_H_
 #define NCM_STRL_H_ 1
 
+#include <stdbool.h>
+
+bool strnkcpy (char *dest, const char *src, size_t size);
+bool strnkcat (char *dest, const char *src, size_t size);
+
 #ifndef HAVE_STRLCPY
 size_t strlcpy (char *dest, const char *src, size_t size);
 #endif /* HAVE_STRLCPY */

ncmlib/strlist.c

@@ -46,7 +46,7 @@ void add_to_strlist(strlist_t **list, char *name)
 	len = strlen(name) + 1;
 	if (len == 1) return;
 	s = xmalloc(len);
-	strlcpy(s, name, len);
+	strnkcpy(s, name, len);
 
 	item = xmalloc(sizeof (strlist_t));
 	item->str = s;