Travis Vitek wrote: > > > If rw_snprintf() is intended to behave like sprintf(), it should probably > append the null terminator. If not, I should probably revise my fix to > STDCXX-524 [https://issues.apache.org/jira/browse/STDCXX-524]. > >
I think it should but the patch doesn't actually make it do that. I wrote a small test case to check (see below). here are the results with the patch: rw_snprintf(0, "0123") ==> 4: "********" snprintf (0, "0123") ==> 4: "********" rw_snprintf(1, "0123") ==> 4: "********" snprintf (1, "0123") ==> 4: "\0*******" rw_snprintf(2, "0123") ==> 4: "********" snprintf (2, "0123") ==> 4: "0\0******" rw_snprintf(3, "0123") ==> 4: "********" snprintf (3, "0123") ==> 4: "01\0*****" rw_snprintf(4, "0123") ==> 4: "********" snprintf (4, "0123") ==> 4: "012\0****" rw_snprintf(5, "0123") ==> 4: "0123\0***" snprintf (5, "0123") ==> 4: "0123\0***" rw_snprintf(6, "0123") ==> 4: "0123\0***" snprintf (6, "0123") ==> 4: "0123\0***" I committed a slightly different patch the does what I think we want: http://svn.apache.org/viewvc?rev=605389&view=rev Let me know if you see a problem with it. Martin > > Travis > > > Index: printf.cpp > =================================================================== > --- printf.cpp (revision 605328) > +++ printf.cpp (working copy) > @@ -3376,8 +3376,10 @@ > > va_end (va); > > - if (size_t (nchars) <= bufsize) > + if (size_t (nchars) < bufsize) { > memcpy (buf, tmpbuf, size_t (nchars)); > + buf [nchars] = 0; > + } > > free (tmpbuf); > #include <rw_printf.h> #include <stdio.h> void test (int n, const char *s) { char buf1[8] = { '*', '*', '*', '*', '*', '*', '*', '*' }; char buf2[8] = { '*', '*', '*', '*', '*', '*', '*', '*' }; int m; m = rw_snprintf (buf1, n, s); rw_printf ("rw_snprintf(%d, %#s) ==> %d: %{#*s}\n", n, s, m, int (sizeof buf1), buf1); m = snprintf (buf2, n, s); rw_printf ("snprintf (%d, %#s) ==> %d: %{#*s}\n", n, s, m, int (sizeof buf2), buf2); } int main () { test (0, "0123"); test (1, "0123"); test (2, "0123"); test (3, "0123"); test (4, "0123"); test (5, "0123"); test (6, "0123"); } -- View this message in context: http://www.nabble.com/-PATCH--rw_snprintf-doesn%27t-null-terminate-strings-tp14407607p14410127.html Sent from the stdcxx-dev mailing list archive at Nabble.com.
