Linux exit() and

/***** exit1.c ******/#include<stdio.h>#include<stdlib.h>main(){ printf("output begin /n"); printf("content in buffer"); exit(0);}
 Use the exit() function to write the contents of the file buffer back to the file before ending the process. This is a safer way to exit. 
 The following _exit() function does not process the buffer and clears it directly before ending the process, so the risk is relatively large. 
 
/***** exit2.c ******/#include<stdio.h>#include<unistd.h>main(){printf(" Output begin/n");printf("content in buffer");_exit(0);}Run result:
 
 Above:
output begin content in buffer
 
 The following: 
 
 
output begin