is there another way to PAUSE the command prompt ?!

[Meshal]

is there another way to PAUSE the command prompt without using

system(PAUSE);

??!!

[Ken Fitlike]

faq.

[Meshal]

thnks

[Meshal]

but there is a simple questions --->

what fflush() really do ??

i read that it :
fflush() causes any unwritten data for that stream to be written to the file
fflush() function causes any buffered output data for stream to be written to file

but i don`t understand what buffered mean here !!

what`s the buffered output data

ex:

FILE *fp = fopen("file.txt","rw");
fflush(fp);
is this meaningfull ??

and there is something called flush()
is it the same with fflush()

i know i ask many question but i want to learn that`s all ..

[King Mir]

but there is a simple questions --->

what fflush() really do ??

i read that it :
fflush() causes any unwritten data for that stream to be written to the file
fflush() function causes any buffered output data for stream to be written to file

When you work with a file, the data that you write to the file is first stored in a memmory 'buffer'. When this buffer gets full, or when you tell the program to flush the buffer, then any data in the buffer gets writen to the harddisk or wherever the file is actually located.

[Meshal]

When you work with a file, the data that you write to the file is first stored in a memmory 'buffer'. When this buffer gets full, or when you tell the program to flush the buffer, then any data in the buffer gets writen to the harddisk or wherever the file is actually located.

ammm , so why this program doesn`t do as you say ?

main()
{

FILE *fp = fopen("file.txt","r+w"); //file.txt empty file!

printf("this will be printed to the file");

fflush(fp);
}

after opening the file file.txt i see nothing ?! why

[OnionKnight]

ammm , so why this program doesn`t do as you say ?

main()
{

FILE *fp = fopen("file.txt","r+w"); //file.txt empty file!

printf("this will be printed to the file");

fflush(fp);
}

after opening the file file.txt i see nothing ?! why

No, it will be printed to stdout. Use

fprintf(fp, "this will be printed to the file");

instead.

[ssharish2005]

is there another way to PAUSE the command prompt without using

system(PAUSE);

??!!

can use getchar() as well

ssharish2005

[Meshal]

till now i don`t know why we need fflush() and how we use it in the program

[whiteflags]

There is at least one level of indirection from raw input from hardware to your output device (perhaps a screen). The memory where this input is stored needs to be flushed as it fills up with data, so that you don't run into a situation where the memory is full and you miss something, or worse, can't accept new input. Now, in C's standard implementation, the OS will typically make an educated guess, flushing this memory if it recieves a newline and whatever data it contained is written to the output device.

Now if you neglect to include a newline with your output or the system doesn't flush when you expect it to, you need to do it yourself, hence, fflush(FILE*).

fflush only works with output streams (like files opened with "w" and stdout) and not input streams (like stdin). This is chiefly because writing to an input stream does not make any sense. Can you write to a keyboard? How about a mouse? Input devices "read things" or report events only, and have no business doing any "writing," as far as I know.

[Meshal]

understood , and i need to know about system more
i`ll buy then (Advanced Unix Programming) to learn more about this stuff !

thanks for your help and explain to fflush ,

but there is still a question hasn`t been answered !!!!!!!!!!

=========================
and there is something called flush()
is it the same with fflush()
=========================

[whiteflags]

> and there is something called flush()
Not in standard C.