how to check is a file is empty

[vincec]

Hi, i would like to check is a file is empty after opening it using i/o processing.
is there any function provide by fstream to check is a file is empty?

thanks.

[DeMan]

If you mean empty (as opposed to does not exist) i would suggest checking whether you are at EOF (end of file)

[horace1]

Hi, i would like to check is a file is empty after opening it using i/o processing.
is there any function provide by fstream to check is a file is empty?

thanks.

you can use the fstat() function to obtain information on a file including its size, e.g. see file_stat.st_size in the following program

// read file status, print size, dates etc
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
int main()
{
struct stat file_stat;
int         status;
char filename[50]={0};
printf("enter filename ? ");
scanf("%s", filename);
int fildes = open(filename, O_RDWR);             // open file
 
// get file status for details see
// http://www.opengroup.org/onlinepubs/007908799/xsh/fstat.html
status = fstat(fildes, &file_stat);                 // get its status
 
// print file status informations for details see
//   http://www.opengroup.org/onlinepubs/007908799/xsh/sysstat.h.html
printf("file %s size %d\n", filename, file_stat.st_size);        // print status
printf("last access %s\n", ctime(&file_stat.st_atime));
printf("last mofification %s\n", ctime(&file_stat.st_mtime));
printf("last status change %s\n", ctime(&file_stat.st_ctime));
return 0;
}