string: split strcat and strncat (DONE)

CMakeLists.txt

@@ -142,6 +142,7 @@ set(SOURCES
   src/libc/string/strcpy.c
   src/libc/string/strdup.c
   src/libc/string/strlen.c
+  src/libc/string/strncat.c
   src/libc/string/strncmp.c
   src/libc/string/strncpy.c
   src/libc/string/strnlen.c

src/libc/string/strcat.c

@@ -1,16 +1,5 @@
 #include <string.h>
 
-/*
-** The  strcat()  function  appends  the src string to the dest string,
-** overwriting the terminating null byte ('\0') at the end of dest, and then
-** adds a terminating null byte. The strings may not overlap, and the dest
-** string must have enough space for the result. If dest is not large enough,
-** program behavior is unpredictable; buffer overruns are a favorite avenue for
-** attacking secure programs.
-**
-** TODO: use the DMA !
-** TODO: look at the DSP ?
-*/
 char *strcat(char *dest, char const *src)
 {
 	size_t i;
@@ -26,25 +15,3 @@ char *strcat(char *dest, char const *src)
 	dest[i + start] = '\0';
 	return (dest);
 }
-
-/*
-** The strncat() function is similar, except that:
-**   *  it will use at most n bytes from src; and
-**   *  src does not need to be null-terminated if it contains n or more bytes.
-**
-** As with strcat(), the resulting string in dest is always null-terminated.
-**
-** If src contains n or more bytes, strncat() writes n+1 bytes to dest (n from
-** src plus the terminating null byte). Therefore, the size of dest must be at
-** least strlen(dest)+n+1.
-*/
-char *strncat(char *dest, const char *src, size_t n)
-{
-	size_t dest_len = strlen(dest);
-	size_t i;
-
-	for (i = 0; i < n && src[i] != '\0'; i++)
-		dest[dest_len + i] = src[i];
-	dest[dest_len + i] = '\0';
-	return (dest);
-}

src/libc/string/strncat.c

@@ -0,0 +1,12 @@
+#include <string.h>
+
+char *strncat(char *dest, const char *src, size_t n)
+{
+	size_t dest_len = strlen(dest);
+	size_t i;
+
+	for (i = 0; i < n && src[i] != '\0'; i++)
+		dest[dest_len + i] = src[i];
+	dest[dest_len + i] = '\0';
+	return (dest);
+}