BBC BASIC Programmers' Reference

by Richard Russell, April 2013

The code below list the files on an FTP server.

      FTP_PORT = 21 : REM default for FTP servers
      _INTERNET_SERVICE_FTP = 1
      OPEN_TYPE_PRECONFIG = 0 : REM use registry configuration
      OPEN_TYPE_DIRECT = 1 : REM direct to net
      OPEN_TYPE_PROXY = 3 : REM via named proxy
      OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY = 4 : REM prevent using Java

      SYS "LoadLibrary", "WININET.DLL" TO wininet%
      SYS "GetProcAddress", wininet%, "InternetOpenA"           TO `InternetOpen`
      SYS "GetProcAddress", wininet%, "InternetConnectA"        TO `InternetConnect`
      SYS "GetProcAddress", wininet%, "FtpSetCurrentDirectoryA" TO `FtpSetCurrentDirectory`
      SYS "GetProcAddress", wininet%, "FtpFindFirstFileA"       TO `FtpFindFirstFile`
      SYS "GetProcAddress", wininet%, "InternetFindNextFileA"   TO `InternetFindNextFile`
      SYS "GetProcAddress", wininet%, "InternetCloseHandle"     TO `InternetCloseHandle`

      DIM _FILETIME{dwLowDateTime%, dwHighDateTime%}
      DIM findData{dwFileAttributes%, \
      \            ftCreationTime{} = _FILETIME{}, \
      \            ftLastAccessTime{} = _FILETIME{}, \
      \            ftLastWriteTime{} = _FILETIME{}, \
      \            nFileSizeHigh%, nFileSizeLow%, \
      \            dwReserved0%, dwReserved1%, \
      \            cFileName&(259), cAlternate&(13), padding&(1)}

      FTPserver$ = "ftp.cs.brown.edu"
      UserName$ = "anonymous"
      Password$ = ""
      Directory$ = "pub"

      REM Open an internet connection:
      SYS `InternetOpen`, "BBC BASIC for Windows", OPEN_TYPE_PRECONFIG, 0, 0, 0 TO hOpen%
      IF hOpen% = 0 ERROR 100, "Cannot open internet connection"

      REM Connect to the FTP server:
      SYS `InternetConnect`, hOpen%, FTPserver$, FTP_PORT, \
      \                      UserName$, Password$, _INTERNET_SERVICE_FTP, 0 , 0 \
      \                      TO hConnection%
      IF hConnection% = 0 ERROR 100, "Cannot open FTP connection"

      REM Set the current directory:
      SYS `FtpSetCurrentDirectory`, hConnection%, Directory$ TO res%
      IF res% = 0 ERROR 100, "Cannot set current directory"

      REM List the directory:
      SYS `FtpFindFirstFile`, hConnection%, 0, findData{}, 0, 0 TO hSearch%
      IF hSearch% = 0 ERROR 100, "Cannot list directory contents"
      REPEAT
        PRINT findData.nFileSizeLow% TAB(12) findData.cFileName&()
        SYS `InternetFindNextFile`, hSearch%, findData{} TO res%
      UNTIL res% = 0

      REM Close the search:
      SYS `InternetCloseHandle`, hSearch%

      REM Close the FTP connection:
      SYS `InternetCloseHandle`, hConnection%

      REM Close the internet connection:
      SYS `InternetCloseHandle`, hOpen%