fflush

I'm currently implementing a ping/pong buffering scheme to safely write a file to disk. I'm using C++/Boost on a Linux/CentOS machine. Now I'm facing the problem to force the actual write of the file to disk. Is it possible to do so irrespective of all the caching policies of the filesystem (ext3/ext4) / SO custom rules / RAID controller / harddisk controller ? Is it best to use plain fread()/fwrite(), c++ ostream or boost filesystem? I've heard that simply flushing out the file (fflush()) doesn't guarantee the actual write fflush (for FILE*), std::flush (for IOStream) to force your program to

Below is sample code for using fflush(): #include <string.h> #include <stdio.h> #include <conio.h> #include <io.h> void flush(FILE *stream); int main(void) { FILE *stream; char msg[] = "This is a test"; /* create a file */ stream = fopen("DUMMY.FIL", "w"); /* write some data to the file */ fwrite(msg, strlen(msg), 1, stream); clrscr(); printf("Press any key to flush DUMMY.FIL:"); getch(); /* flush the data to DUMMY.FIL without closing it */ flush(stream); printf("\nFile was flushed, Press any key to quit:"); getch(); return 0; } void flush(FILE *stream) { int duphandle; /* flush the stream's

Well I been doing a lot of searching on google and on here about how to flush the input stream properly. All I hear is mixed arguments about how fflush() is undefined for the input stream, and some say just do it that way, and others just say don't do it, I haven't had much luck on finding a clear efficient/proper way of doing so, that the majority of people agree on.. I am quite new at programming so I don't know all the syntax/tricks of the language yet, so my question which way is the most efficient/proper solution to clearing the C input stream?? Use the getchar() twice before I try to

After wasting too much time searching why my program doesn't execute gets() after using scanf(), I found a solution which is to use fflush(stdin) after scanf() to enable gets() to get a string. The problem is that fflush(stdin) doesn't do what is expected from it: The program continues skipping gets() and I can't write any phrase in the console to be read. My code is the next one: #include <string.h> #include <stdio.h> int main(){ char nombre[10]; char mensaje[80]; printf("Type your name:\n"); scanf("%s", nombre); fflush(stdin); printf("Now, type a message:\n"); gets(mensaje); printf("3/%s:%s"

I can't seem to figure out what's wrong with this code: #include <stdio.h> #include <ctype.h> #include <string.h> #include <stdlib.h> #define MAX 100 #define TRUE 1 #define FALSE 0 char sect_cat; char customer_name[MAX]; char customer_number[MAX]; /* error handling is easier */ int prev_unit = 0; int current_unit = 0; int consumed = 0; int set = FALSE; float init_bill; float tax; float total_bill; void get_userinfo() { printf("Enter sector category: "); scanf("%c", &sect_cat); printf("Enter customer name: "); fflush(stdin); scanf("%sn", &customer_name); set = FALSE; while (set == FALSE) {

Should fflush() not be used to flush a buffer even if it is an output stream? What is it useful for? How do we flush a buffer in general? Mike Flushing the output buffers: printf("Buffered, will be flushed"); fflush(stdout); // Prints to screen or whatever your standard out is or fprintf(fd, "Buffered, will be flushed"); fflush(fd); //Prints to a file Can be a very helpful technique. Why would you want to flush an output buffer? Usually when I do it, it's because the code is crashing and I'm trying to debug something. The standard buffer will not print everytime you call printf() it waits