Programming

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <fcntl.h>
#include <errno.h>

int sync_file(char *file)
{
FILE *fp=NULL;
int fd;

printf("file is %s\n",file);
fp = fopen(file, "r");
if(!fp)
return -1;

fd = fileno(fp);
fflush(fp);
fsync(fd);
ioctl (fd, BLKFLSBUF, 0);
fclose(fp);
return 0;

}

int main()
{
int len=0;
FILE *fp = NULL;
char buf[1024];
char *fname = "/etc/test.conf";
char fname_tmp[129] = "";


len = sprintf(buf, "%s\n", "Newly added Line is there");

snprintf(fname_tmp, 128, "%s.tmp", fname);

if( (fp = fopen(fname_tmp,"a")) == NULL )
printf(" ERROR: open(), error - %s\n",strerror(errno));

fprintf(fp,"%s",buf);
fflush(fp);

fsync(fileno(fp));
fclose(fp);
system("cp -f /etc/test.conf.tmp /etc/test.conf");
// system("mv -f /etc/test.conf.tmp /etc/test.conf");
sync_file(fname);
return 0;
}

 
cat:$ls -i 1
82309 1
cat:$mv 1 2
cat:$ls -i 2
82309 2

cat:$ls > 1
cat:$cp 1 2
cat:$ls -i 1 2
82964 1  82967 2