vsprintf: split out '%s' handling logic
Linus Torvalds [Sun, 6 Jul 2008 23:06:25 +0000 (16:06 -0700)]
The actual code is the same, just split out into a helper function.
This makes it easier to read, and allows for future sharing of the
string code.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/vsprintf.c

index 6021757..926c7e0 100644 (file)
@@ -482,6 +482,35 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int
        return buf;
 }
 
+static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags)
+{
+       int len, i;
+
+       if ((unsigned long)s < PAGE_SIZE)
+               s = "<NULL>";
+
+       len = strnlen(s, precision);
+
+       if (!(flags & LEFT)) {
+               while (len < field_width--) {
+                       if (buf < end)
+                               *buf = ' ';
+                       ++buf;
+               }
+       }
+       for (i = 0; i < len; ++i) {
+               if (buf < end)
+                       *buf = *s;
+               ++buf; ++s;
+       }
+       while (len < field_width--) {
+               if (buf < end)
+                       *buf = ' ';
+               ++buf;
+       }
+       return buf;
+}
+
 /**
  * vsnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
@@ -502,11 +531,9 @@ static char *number(char *buf, char *end, unsigned long long num, int base, int
  */
 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 {
-       int len;
        unsigned long long num;
-       int i, base;
+       int base;
        char *str, *end, c;
-       const char *s;
 
        int flags;              /* flags to number() */
 
@@ -622,29 +649,7 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
                                continue;
 
                        case 's':
-                               s = va_arg(args, char *);
-                               if ((unsigned long)s < PAGE_SIZE)
-                                       s = "<NULL>";
-
-                               len = strnlen(s, precision);
-
-                               if (!(flags & LEFT)) {
-                                       while (len < field_width--) {
-                                               if (str < end)
-                                                       *str = ' ';
-                                               ++str;
-                                       }
-                               }
-                               for (i = 0; i < len; ++i) {
-                                       if (str < end)
-                                               *str = *s;
-                                       ++str; ++s;
-                               }
-                               while (len < field_width--) {
-                                       if (str < end)
-                                               *str = ' ';
-                                       ++str;
-                               }
+                               str = string(str, end, va_arg(args, char *), field_width, precision, flags);
                                continue;
 
                        case 'p':