How to override the DCB attributes in SFTP with phpseclib

Question

I've a link where I saw the reference to change the default attributes & set the required mode to transfer the dataset through SFTP.

Here is how it is..

sftp> ls /+mode=text,lrecl=80,recfm=fb

In this, we change the mode to text (where default is the binary mode).

When I execute this through command prompt it works fine and gives the same response which means the command executed perfectly!

(Response after executing in command prompt)

sftp> ls /+mode=text,lrecl=80,recfm=fb
/+mode=text,lrecl=80,recfm=fb 

But if I try to use the same through the PHP code it throws me the error as

ls: FSUM6785 File or directory "/+mode=text,lrecl=80,recfm=fb" is not found

Here is how I used using the phpseclib library:

 define('NET_SFTP_LOGGING', NET_SFTP_LOG_COMPLEX);
 $user = 'username';
 $host = 'host';
 $key = new Crypt_RSA();
 $key->loadKey(file_get_contents('file.ppk'));
 $sftp = new Net_SFTP($host);
 if ($sftp->login($user,$key)) {
     echo $sftp->exec('ls /+mode=text,lrecl=80,recfm=fb');
 } else {
     return false;
 }

In the above if I try with $sftp->exec('ls -la'); and $sftp->exec('pwd'); it gives me the list of directories present & the current directory respectively.. which means the SFTP connection is fine and the exec command works.

But the same throws error when I use the ls /+mode=text,lrecl=80,recfm=fb commands as mentioned above.

Is there any other thing that need to be set to make these /+mode=text..... commands to work

Answer 1

sftp> ls /+mode=text,lrecl=80,recfm=fb

The above is OpenSSH sftp client command ls. Internally, it issues a sequence of SFTP requests (OPENDIR, READDIR, CLOSE) to retrieve a directory listing.

The SFTP server is implemented to treat OPENDIR with that unique syntax specifically, as documented in the article you link to.

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echo $sftp->exec('ls /+mode=text,lrecl=80,recfm=fb');

While the above executes a remote shell ls command. The shell ls command does not have a special treatment for the syntax and considers it a path and fails.

Note that while you execute the exec on $sftp instance, the method is actually implemented in parent SSH2 class and has nothing to do with SFTP.

---

To emulate the ls command of OpenSSH sftp (i.e. to send OPENDIR SFTP request), use some of the directory listing commands of SFTP class, like nlist or rawlist:

$sftp->nlist('/+mode=text,lrecl=80,recfm=fb');