A quick test reveals DBG("foo\n") succeeds whereas printf & std::cout produce no console output (testing in Visual Studio, normally I would use OSX but this rotten eyetracker only works on Windows).
It's strange, I thought I remembered noting std::cout working a few days back...
Does this mean JUCE is hijacking console output?
How would I handle something like:
printf( "x,y = %.1f, %.1f\n", x, y );
?
π
If you look at the code for JUCE's DBG macro, under Visual Studio it streams to a Windows specific API that makes it print to the VS "output" pane since there's no standard console for printf() or std::cout to print to under the Windows subsystem which Windows JUCE applications use.
If I have to use my own stringstream object instead of the DBG macro, (for example if I wanted to print a bunch of things in a for loop without a newline every time, which DBG always sticks on the end) I usually just make an std::ostringstream object, push stuff into it like I would std::cout, then before it goes out of scope and disappears use DBG(<ostringstream_var>.str()) to print it out to VS's output.
Using http://stackoverflow.com/questions/69738/c-how-to-get-fprintf-results-as-a-stdstring-w-o-sprintf#69911
// http://stackoverflow.com/questions/69738/c-how-to-get-fprintf-results-as-a-stdstring-w-o-sprintf#69911
#include <string>
#include <cstdarg>
#include <vector>
#include <string>
#include <cstdarg>
class PiString
{
private:
static
std::string
vformat(const char *fmt, va_list ap)
{
// Allocate a buffer on the stack that's big enough for us almost
// all the time. Be prepared to allocate dynamically if it doesn't fit.
size_t size = 1024;
char stackbuf[1024];
std::vector<char> dynamicbuf;
char *buf = &stackbuf[0];
while (1) {
// Try to vsnprintf into our buffer.
int needed = vsnprintf(buf, size, fmt, ap);
// NB. C99 (which modern Linux and OS X follow) says vsnprintf
// failure returns the length it would have needed. But older
// glibc and current Windows return -1 for failure, i.e., not
// telling us how much was needed.
if (needed <= (int)size && needed >= 0) {
// It fit fine so we're done.
return std::string(buf, (size_t)needed);
}
// vsnprintf reported that it wanted to write more characters
// than we allotted. So try again using a dynamic buffer. This
// doesn't happen very often if we chose our initial size well.
size = (needed > 0) ? (needed + 1) : (size * 2);
dynamicbuf.resize(size);
buf = &dynamicbuf[0];
}
}
public:
static
std::string
format(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
std::string buf = vformat(fmt, ap);
va_end(ap);
return buf;
}
};
I can do the following:
#define DBG2(...) DBG( PiString::format(__VA_ARGS__ ) )
DBG2("Gaze Data: (%.1f, %.1f) timestamp %.0f ms\n", eventParams.X, eventParams.Y, eventParams.Timestamp);
π
PS Alternatively:
#include <sstream> #include <iomanip> // std::setprecision std::ostringstream s; s << "x=" << std::setprecision(3) << eventParams.X; DBG( s.str() );
but .. yuck!
Hello forum people! Upgrading the forum has produced artefacts in old code. This makes a lot of old code unreadable.
It needs a script to run through the database doing a search&replace.
I’ve mentioned this 3 or 4 times… I hope someone is listening!
π
Also, nobody has said where printf output actually DOES go.
Say I’m using a third-party C library – I don’t want to have to rework every line involving printf.
Is there some way to access the output?
π
