[PATCH] make sscanf honor %n at end of input string
I was playing with some code that sometimes got a string where a %n match should have been done where the input string ended, for example like this: sscanf("abc123", "abc%d%n", , ); However, the scanf function in the kernel doesn't convert the %n in that case because it has already matched the complete input after %d. This patch changes that. Signed-off-by: Johannes Berg <[EMAIL PROTECTED]> --- Shrug. My use case for this collapsed, but I figured having scanf doing that correctly might be a good thing. lib/vsprintf.c |9 + 1 file changed, 9 insertions(+) --- wireless-dev.orig/lib/vsprintf.c2007-03-01 00:28:31.776381760 +0100 +++ wireless-dev/lib/vsprintf.c 2007-03-01 00:59:33.256381760 +0100 @@ -825,6 +825,15 @@ int vsscanf(const char * buf, const char break; str = next; } + + /* Now we've come all the way through so either the input string or +* the format ended. In the former case, there can be a %n at the +* current position in the format that needs to be filled. */ + if (*fmt == '%' && *(fmt+1) == 'n') { + int *i = (int *)va_arg(args,int*); + *i = str - buf; + } + return num; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] make sscanf honor %n at end of input string
I was playing with some code that sometimes got a string where a %n match should have been done where the input string ended, for example like this: sscanf(abc123, abc%d%n, a, n); However, the scanf function in the kernel doesn't convert the %n in that case because it has already matched the complete input after %d. This patch changes that. Signed-off-by: Johannes Berg [EMAIL PROTECTED] --- Shrug. My use case for this collapsed, but I figured having scanf doing that correctly might be a good thing. lib/vsprintf.c |9 + 1 file changed, 9 insertions(+) --- wireless-dev.orig/lib/vsprintf.c2007-03-01 00:28:31.776381760 +0100 +++ wireless-dev/lib/vsprintf.c 2007-03-01 00:59:33.256381760 +0100 @@ -825,6 +825,15 @@ int vsscanf(const char * buf, const char break; str = next; } + + /* Now we've come all the way through so either the input string or +* the format ended. In the former case, there can be a %n at the +* current position in the format that needs to be filled. */ + if (*fmt == '%' *(fmt+1) == 'n') { + int *i = (int *)va_arg(args,int*); + *i = str - buf; + } + return num; } - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/