rin67630 / print-date-of-yesterday Goto Github PK

Many of us have a C++ program that issues shortly after midnight the summary of the past day.
It should issue the summary in a line appended to a file. That file should be in the csv format, for e.g. post processing in Excel.
But you need to begin the line with a date identifier. And that identifier should be the day of yesterday (because you print it after midnight)

I searched and did not find nice solutions. So I dug into the guts of C++ ctime and propose that solution:

//***Variables for Time***
tm* timeinfo;  
tm* yesterdaytimeinfo;  
time_t now;
time_t yesterdaynow;
static char charbuff[120];  //Char buffer for many functions
 
 
//*** In program ***
yesterdaynow = now - 86400;
yesterdaytimeinfo = localtime(&yesterdaynow);
strftime(charbuff, 30, "%x ", yesterdaytimeinfo);
println();
print(charbuff);

That's it.

Enjoy !