Hi, i want to sprintf() an unsigned long long value in visual C++ 6.0 (plain C).
char buf[1000]; //bad coding
unsigned __int64 l = 12345678;
char t1[6] = "test1";
char t2[6] = "test2";
sprintf(buf, "%lli, %s, %s", l, t1, t2);
gives the result
12345678, (null), test1
(watch that test2 is not printed)
and l = 123456789012345 it gives an exception handle
any suggestions?
-
Apparently, you did not assign
additionaltext
to the necessarychar *
(string). Note that thelong int
was processed, the comma was copied and only the%s
generated(null)
. -
printf uses the ellipsis to pass a variable argument list. The (null) you see is the second part of your long long, which happen to be all 0 bits. Set it to 1<<60+1<<30 and you'll get a crash as the 1<<60 part is interpreted as a char*.
The correct solution would be to break down the number in three parts of 10 digits, "verylongvalue % 10000000000" "(verylongvalue/10000000000) % 10000000000" "verylongvalue/100000000000000000000".
Peter Miehle : thanks for bringing up the ellipse, i did forget that thing -
To print an
unsigned __int64
value in Visual C++ 6.0 you should use%I64u
, not%lli
(refer to this page on MSDN).%lli
is only supported in Visual Studio 2005 and later versions. So, your code should be:sprintf(buf, "%I64u, %s, %s", l, t1, t2);
Peter Miehle : sure it is 6, typo corrected, thanks
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