sprintf with a uint64_t variable?

[benkokes]

Is there a compiler/makefile flag that allows for 64bit printing?

I have included inttypes.h, and tried both %llu and "PRI64" as shown:

    char scrbuf[30];
    uint64_t time_alive = 12345678;
    uint8_t tempret =0;

	sprintf(scrbuf," "%llu  "",time_alive );
	tempret = sprintf(scrbuf, ""PRIu64"    ",time_alive );

In both cases, the only thing that gets pushed to 'scrbuf' are the values of "l" and "u" to the first and second memory positions. I step through and view each of them in the debugger.

Any insight as to what I may be missing? Some sort of #define or some compiler flag? I am using the BLE HRS example as a base. This is all nrf51_SDK_10.0.0

[Susheel Nuguru]

mostly because llu should go inside the quotes and for PRUu64 % should go inside the quotes.

sprintf(scrbuf,"%llu",time_alive );
tempret = sprintf(scrbuf, "%"PRIu64" ",time_alive );

[benkokes]

Hi Aryan,

Thakns for the reply. I made the changes you suggested. No change.

Are you certain that a compiler flag isn't required to take advantage of the 'llu' format?

I do 64 bit math ( adds, divides,etc) that seem to be correct, this seems to be focused specifically on that sprintf. Maybe a different type of sprintf is needed?

Thanks, -Ben

[benkokes]

Resolved.

My specific problem stemmed from the fact that I was running a super stripped down version of newlib library and didn't even know it.

In my makefile, I had the line

  LDFLAGS += --specs=nano.specs -lc -lnosys

which seems to be the bare-essentials to run things like sprintf, etc. You disable it by putting a pound sign in front of the statement (for those who dont know, the '#' is how you comment out a line in a makefile)

  #LDFLAGS += --specs=nano.specs -lc -lnosys   <-COMMENTED OUT

For folks that are new, look/research for libc or newlib and its associated documentation. Some scripting games are played with the nano directive to reduce the newlib to the absolute essentials to run. It stripped out the ability for sprintf to handle 64bit values, which held me up in my project...

Hope that helps.

[Susheel Nuguru]

good to know :)

[Robert Massaioli]

I just ran into this exact same issue when trying to use NRF_LOG_PRINTF is SDK 11.0.0.

Commenting out that line and clean rebuilding fixed this issue and let me use %llu to print out uint64_t types.