An atomic operation is an operation that can only be done once at a certain "tick" time, eventhough another same operation is simultaneously performed by another thread on another CPU core.
For example
Code:
mkdir /home/flag
is an atomic operation (without the -p option)
so that even if you submit it many time
if I rename a dir
mv dir dir2
Is this operation atomic? Suppose there 100 files in dir, does linux rename them one by one or at once?
In other words, is there a time at which both dir and dir2 exist, with dir has, say 30 files and dir2 has the rest 70 files? (4 Replies)
Hello,
I need to implement a locking system in C. My problem is how to make the check if the lock file exist and locking it atomic operation.
I want to make something like this:
FILE* lock_fname;
lock_fname = fopen ( "file.lock", "r");
/*check if file exsists*/
if (lock_fname)
{
fclose... (7 Replies)
hi guys.
can we use fread and fwrite with pipes to write data more than PIPE_BUF atomically since they lock FILE object until I/O operation finish? (1 Reply)
Are system calls atomic operations?
Is a system call can be interrupted? (2 Replies)
Discussion started by: vistastar
2 Replies
LEARN ABOUT PHP
ssh2_sftp_mkdir
SSH2_SFTP_MKDIR(3) 1 SSH2_SFTP_MKDIR(3)ssh2_sftp_mkdir - Create a directorySYNOPSIS
bool ssh2_sftp_mkdir (resource $sftp, string $dirname, [int $mode = 0777], [bool $recursive = false])
DESCRIPTION
Creates a directory on the remote file server with permissions set to $mode.
This function is similar to using mkdir(3) with the ssh2.sftp:// wrapper.
PARAMETERS
o $sftp
- An SSH2 SFTP resource opened by ssh2_sftp(3).
o $dirname
- Path of the new directory.
o $mode
- Permissions on the new directory.
o $recursive
- If $recursive is TRUE any parent directories required for $dirname will be automatically created as well.
RETURN VALUES
Returns TRUE on success or FALSE on failure.
EXAMPLES
Example #1
Creating a directory on a remote server
<?php
$connection = ssh2_connect('shell.example.com', 22);
ssh2_auth_password($connection, 'username', 'password');
$sftp = ssh2_sftp($connection);
ssh2_sftp_mkdir($sftp, '/home/username/newdir');
/* Or: mkdir("ssh2.sftp://$sftp/home/username/newdir"); */
?>
SEE ALSO mkdir(3), ssh2_sftp_rmdir(3).
PHP Documentation Group SSH2_SFTP_MKDIR(3)
10-29-2012
