Printf function buffer problem

A recently executed code , Use printf When , Forget to add \n 了 , The result has not been printed . Check the program configuration and logic repeatedly , No problem. . Wasted half a day , Finally, I found that I stepped into the pit .., This situation is hereby recorded .

The following code , If not printf("\n") or fflush(stdout) Will not show printf Result . Or change to printf("%s\n", str1) Will display the print results .

You can also put while(1); Get rid of , The program can also be refreshed after execution printf The buffer , Print out the results .

This is related to printf Of buffer It matters .

#include <stdio.h>

int main(int argc, char **argv)
{
    
        char *str1 = "str1 printing...";
        char *str2 = "str2 printing...";

        printf("%s", str1);
        printf("%s", str2);

// printf("\n");
// fflush(stdout);

        while(1);

        return 0;
}

Buffer refresh condition ：
1. End of process .
2. encounter \n.
3. Buffer full . printf The buffer size of the function is 1024 Bytes , When the buffer size is exceeded , The buffer will be flushed , The results will be printed .
4. Refresh buffer manually fflush(stdout).
5. call exit(0); But you can also call _exit(0), Do not flush the buffer .