我试图在NFS中锁定文件，所以我尝试了以下操作，首先我已经使用了CLI
NSArray *searchResult;
UISearchController *mysearchController;
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
//code here for select the cell amd put the name of the SegueIdentifier
[self performSegueWithIdentifier:@"getDetail" sender:indexPath];
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if ([segue.identifier isEqualToString:@"getDetail"]) {
if (searchResult != nil) {
DetailViewController *detailViewController = segue.destinationViewController;
NSIndexPath *indexPath = (NSIndexPath *) sender;
NSDictionary *item = searchResult[indexPath.row];
detailViewController.detailName = item[@"name"];
detailViewController.detailLocation = item[@"address"];
}else{
DetailViewController *detailViewController = segue.destinationViewController;
NSIndexPath *indexPath = (NSIndexPath *) sender;
NSDictionary *item = self.InfoArray[indexPath.row];
detailViewController.detailName = item[@"name"];
detailViewController.detailLocation = item[@"address"];
}
}
}
然后我发现exec 80>lock.file
echo "testwrite" > &80
flock -s 80 [IO error]
在NFS中锁定文件的情况并不多，所以我打算去flock并编写以下代码
lockf当我在本地运行它时，它编译的代码没有错误锁定文件，但是当我在已安装的路径中运行＆＃39; a.out＆＃34; filename＆＃34;＆＃39;我最终遇到了相同的IO错误。我解雇了 void write_lock(string path)
{
int fd;
int error;
fd = open(path.c_str(), O_CREAT | O_RDWR, 0664);
if (fd < 0) {
perror("open");
exit(EXIT_FAILURE);
}
// if len is zero, lock all bytes
error = lockf(fd, F_LOCK, 0);
if (error == 0){
printf("%#x: lock succeeds!\n", getpid());
cout<<"locked"<<endl;
}
else
{
perror("lockf");
}
sleep(1);
lockf(fd, F_ULOCK, 0);
cout<<"unlocked"<<endl;
close(fd);
}
以嗅探回复消息，当我确实应用锁定（共享/独占）时，它会在下面说明
tshark任何人都可以告诉我，我在这里遇到了什么问题，如果我发现它导致问题的原因我将在c ++ 11中编写代码来完成它......我很难用它来实现