[freenos] r333 committed - Implemented support for length modifiers in format strings with vnspri...
- From: codesite-noreply@xxxxxxxxxx
- To: freenos@xxxxxxxxxxxxx
- Date: Thu, 03 Sep 2009 22:47:48 +0000
Revision: 333
Author: nieklinnenbank
Date: Thu Sep 3 15:47:20 2009
Log: Implemented support for length modifiers in format strings with
vnsprintf().
It allows user applications to specify the length a field must have. When
the format argument uses less space, it is padded with white spaces. If the
format argument uses more bytes than specified by the length modifier, the
output is truncated to the length set by the length modifier.
Fixes issue 30
http://code.google.com/p/freenos/source/detail?r=333
Modified:
/trunk/lib/libc/stdio/vsnprintf.c
=======================================
--- /trunk/lib/libc/stdio/vsnprintf.c Thu Apr 9 14:46:04 2009
+++ /trunk/lib/libc/stdio/vsnprintf.c Thu Sep 3 15:47:20 2009
@@ -22,7 +22,7 @@
int vsnprintf(char *buffer, unsigned int size, const char *fmt, va_list
args)
{
char buf[20], *ptr;
- int ch;
+ int ch, length = -1, i;
unsigned int written = 0;
/* Loop formatted message. */
@@ -35,46 +35,72 @@
}
else
{
+ switch_again:
+
switch (*fmt)
{
- case 'd':
- case 'u':
- itoa(buf, 10, va_arg(args, int));
- ptr = buf;
- goto string;
-
- case 'l':
- itoa(buf, 10, va_arg(args, long));
- ptr = buf;
- goto string;
-
- case 'x':
- itoa(buf, 16, va_arg(args, int));
- ptr = buf;
- goto string;
-
- case 'c':
- buf[0] = va_arg(args, int);
- buf[1] = ZERO;
- ptr = buf;
- goto string;
-
- case 's':
- ptr = va_arg(args, char *);
-
- string:
- while(*ptr && written++ < size)
- {
- *buffer++ = *ptr++;
- }
- break;
-
- default:
- *buffer++ = ch;
- written++;
- break;
+ /* Length modifier. */
+ case '0' ... '9':
+
+ for (i = 0; i < 19 && *fmt >= '0' && *fmt <= '9'; i++)
+ {
+ buf[i] = *fmt++;
+ buf[i+1] = ZERO;
+ }
+ length = atoi(buf);
+ goto switch_again;
+
+ /* Integer. */
+ case 'd':
+ case 'u':
+ itoa(buf, 10, va_arg(args, int));
+ ptr = buf;
+ goto string;
+
+ /* Long integer. */
+ case 'l':
+ itoa(buf, 10, va_arg(args, long));
+ ptr = buf;
+ goto string;
+
+ /* Hexadecimal. */
+ case 'x':
+ itoa(buf, 16, va_arg(args, int));
+ ptr = buf;
+ goto string;
+
+ /* Character. */
+ case 'c':
+ buf[0] = va_arg(args, int);
+ buf[1] = ZERO;
+ ptr = buf;
+ goto string;
+
+ /* String. */
+ case 's':
+ ptr = va_arg(args, char *);
+
+ string:
+ while( ((length == -1 && *ptr) ||
+ (length > 0 && length--)) && written++ < size)
+ {
+ if (*ptr)
+ {
+ *buffer++ = *ptr++;
+ }
+ else
+ *buffer++ = ' ';
+ }
+ break;
+
+ /* Unsupported. */
+ default:
+ *buffer++ = ch;
+ written++;
+ break;
}
fmt++;
+ length = -1;
}
}
/* Null terminate. */
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