bug or illegal code???

[Neil Booth]

Well, it's not ISO C but it's OK GNU syntax.  CVS and recent snapshots
give something along the lines of

# 1 "/home/neil/test.c"


int err_out (char *file, int line, char *fmt, ...)
{
  return 0;
}

int main (int argc, char **argv)
{
   err_out("/home/neil/test.c", 10, "test output: %s\n", "my string");
   err_out("/home/neil/test.c", 11, "test output: %s %d\n", "my string", 1);
}

The preprocessor in RH 7.0 is quite buggy.  I would suggest you
upgrade.

Neil.