Difference between puts() and printf() in C while using sleep()
c, puts, sleep
Solution
This is because of buffering - by default, standard out buffers up to each new line. `printf()` does not include a newline, so output isn't flushed. `puts()` includes a newline, so output is flushed.
You can cause `printf()` to flush by putting a newline:
printf("hello, world\n");
or by calling `fflush()` directly:
fflush(stdout);
For more about buffering, see the man page for `setbuf()`:
The three types of buffering available are unbuffered, block buffered, and
line buffered. When an output stream is unbuffered, information appears on
the destination file or terminal as soon as written; when it is block
buffered many characters are saved up and written as a block; when it
is line buffered characters are saved up until a newline is output or input
is read from any stream attached to a terminal device (typically stdin).
....
If a stream refers to a terminal (as stdout normally does) it is
line buffered.
....
The standard error stream stderr is always unbuffered by default.
Problem
I was wondering the difference between puts() and printf() functions while using sleep() function. Here is my code(In C language): ``` printf("hello, world"); sleep(1); printf("Good, bye!"); ``` After compiling and running the program, it seems that it will sleep first and then print "hello, worldGood, bye!" However, if using puts() instead of printf(), it will print "hello, world" then sleep, and finally print "Good, bye". ``` puts("hello, world"); sleep(1); puts("Good, bye!); ```