Xbase++

Create a Hard Link on an SFTP Server

Demonstrates the Chilkat SFtp.HardLink method, which creates a hard link to an existing remote file. The first argument is the existing file and the second is the new link path. It uses the OpenSSH hardlink@openssh.com extension and succeeds only when the server supports it.

Background: A hard link is a second name for the same file data, not a pointer to a path: both names are equal, the data persists until the last name is removed, and there is no "original" to break. Unlike a symbolic link it cannot span filesystems and cannot target a directory. Because it depends on a non-standard OpenSSH extension, expect it to fail against servers that do not implement it.

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LOCAL nSuccess
LOCAL oSftp
LOCAL nPort
LOCAL cPassword

nSuccess := 0

//  Demonstrates the SFtp.HardLink method, which creates a hard link to an existing remote file.
//  The 1st argument is the existing file and the 2nd is the new link path.

oSftp := CreateObject("Chilkat.SFtp")

//  Connect, authenticate, and initialize the SFTP subsystem.
nPort := 22
nSuccess := oSftp:Connect("sftp.example.com", nPort)
IF (nSuccess == 0)
    ? oSftp:LastErrorText
    oSftp:destroy()
    RETURN
ENDIF

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
cPassword := "mySshPassword"

nSuccess := oSftp:AuthenticatePw("mySshLogin", cPassword)
IF (nSuccess == 0)
    ? oSftp:LastErrorText
    oSftp:destroy()
    RETURN
ENDIF

nSuccess := oSftp:InitializeSftp()
IF (nSuccess == 0)
    ? oSftp:LastErrorText
    oSftp:destroy()
    RETURN
ENDIF

//  Create a hard link.  This uses the OpenSSH hardlink@openssh.com extension and succeeds only
//  when the server supports it.
nSuccess := oSftp:HardLink("subdir/data.bin", "subdir/data_backup.bin")
IF (nSuccess == 0)
    ? oSftp:LastErrorText
    oSftp:destroy()
    RETURN
ENDIF

? "Hard link created."

oSftp:Disconnect()

oSftp:destroy()