RFC 448 (rfc448) - Page 2 of 3
Print files in FTP
Alternative Format: Original Text Document
RFC 448 PRINT FILES IN FTP February 1973 CASE A: Print File with ASA (Fortran) VFC --------------------------------- The first character of each record is a VFC code; see RFC 454 for the codes. Assuming there are to be print files in FTP, these _three_ cases need to be considered. These three cases are explicitly included within the RJE protocol as "transmission" modes; we have borrowed the RJE labels N,T, and A from NIC #12112. The current FTP (RFC 454) seems to provide only _two_ cases: _unformatted_ and _print_file_. It is unclear from RFC 454 how these two FTP formats are related to the three VFC cases. For example, it is unclear whether the FTP format is meant to be a property of the file as transferred over the Network or of the file as stored by the server. As I understand it, the Tenex system supports only case T. The distinction between Case N and Case T is not always clear, however. If a Tenex file which contains only the CR LF combination of format effectors is printed, it may be considered Case N where CR LF delimits a logical record, and where the standard format is to begin printing each record on a new line. The RJE protocol uses this ambiguity to advantage; see below. The IBM operating systems, on the other hand, support Cases N and A. The "output writer" process which drives the printer must know whether or not a file to be printed contains ASA VFC, so the system distinguishes internally between "print files" (Case A) and non-print files (Case N). The "print file" attribute is normally attached to a print file when it is created. For example, the language processors typically create print files for their "printer" output streams. Hence, when CCN's server FTP executes a STOR command, it must decide whether or not the new file is to be marked with the internal print file attribute. As noted earlier, FTP does not explicitly distinguish the three possible cases. We must either add some additional assumptions or server-dependent information outside FTP, or we must add a new format to FTP. IMPLICATIONS OF RJE ------------------- To send an output ("printer") file to a user host, the RJE server will cause his FTP user process to send the file with the following attributes*: *Note: Making the obvious conversion from RFC 385 to RFC 454 terminology. Braden
