smbspool

smbspool job-id user title copies options [file]

This synopsis represents its typical invocation by CUPS as a print backend. smbspool is generally not run directly by users.

job-id
    The CUPS assigned job identification number for the print task.

user
    The username of the user who submitted the print job.

title
    The title or description of the print job.

copies
    The specified number of copies to be printed.

options
    A string containing comma-separated CUPS print options. This often includes authentication details (e.g., 'auth-info-required=negotiate') and the destination printer (e.g., 'dest=printer@server').

[file]
    Optional. The path to the file containing the print data. If this argument is omitted, smbspool reads the print data from standard input (stdin).

smbspool is a critical utility within the Samba suite, primarily designed to facilitate printing from Unix/Linux systems to printers shared via the SMB/CIFS protocol. It functions as a CUPS (Common Unix Printing System) backend. When a CUPS print job is directed to an SMB printer, CUPS invokes smbspool to handle the transmission of the print data. This involves managing the network connection, authenticating to the SMB server, and spooling the print job. It acts as the bridge, translating CUPS print requests into the appropriate SMB commands for remote printing. While its main role is as a CUPS helper, it can also be configured directly within smb.conf for specific print filtering scenarios. Its operation is largely transparent to the end-user, working behind the scenes to enable seamless network printing.

smbspool is a backend utility and not intended for direct user interaction. Its proper functioning heavily relies on the correct configuration of Samba (via smb.conf) and CUPS. Issues often stem from incorrect authentication details, network connectivity problems to the SMB/CIFS server, or misconfigured printer shares. Ensure the necessary Samba client binaries and libraries are installed and accessible.

To use smbspool effectively, it must be configured as a backend for a printer queue within CUPS. This is typically done automatically when adding an SMB printer through the CUPS web interface or command-line tools. CUPS handles passing the necessary arguments (job ID, user, title, copies, options, and print data) to smbspool.

smbspool handles the authentication process required to connect to the SMB/CIFS share. The authentication method (e.g., username/password, Kerberos, NTLM) is usually specified within the CUPS printer URI or via options passed from CUPS. Secure credential handling is crucial, and mechanisms like CUPS's authentication backends or Samba's credential caching are often employed.

Part of the open-source Samba project, smbspool has evolved since the early 1990s as Samba developed robust SMB/CIFS protocol support for Unix-like systems. Its integration with CUPS became standard as CUPS emerged as the dominant printing system on Linux, solidifying smbspool's role as the primary mechanism for printing to Windows and other SMB-shared printers from Unix environments.

cupsd(8), lp(1), lpr(1), smbclient(1), smb.conf(5), testparm(1)