BBC BASIC Programmers' Reference

by Richard Russell, October 2012, corrected August 2015

In the article Sending an email automatically the procedure PROCsendmail() automatically sends an email using the SOCKLIB library. Listed below is a procedure which performs the same function except that you can specify one or more files to attach to the email. The final parameter is a comma-separated list of the pathnames of the file(s) you wish to attach. The procedure might be called as follows:

      INSTALL @lib$+"SOCKLIB"

      SMTP$    = "smtp.gmail.com"
      From$    = "sender@somewhere"
      To$      = "recipient@elsewhere"
      Subject$ = "Test of sending attachments"
      ReplyTo$ = "reallyme@myaddress"
      Message$ = "This is a test of sending an email with attachments."
      Attach$ =  "C:\invoice12345.pdf, " + \
      \          """C:\Program Files\BBC BASIC for Windows\readme.txt"""

      PROCsendmailattach(SMTP$,From$,To$,"","",Subject$,ReplyTo$,Message$,Attach$)

The calling program should first check that the attached files actually exist, because if not PROCattach() will abort with an error and not terminate the SMTP transaction; this could leave the server 'in limbo'. Note that if an attached file path contains spaces or punctuation characters you must enclose it in quotes.

Here is PROCsendmailattach(); like PROCsendmail() it cannot be used if authentication is required so in practice that probably means that your ISP's SMTP server must be used:

      DEF PROCsendmailattach(smtp$,from$,rcpt$,cc$,bcc$,subject$,replyto$,body$,attach$)
      LOCAL D%, S%, skt%, comma%, reply$, file$
      DIM D% LOCAL 31, S% LOCAL 15

      SYS "GetLocalTime", S%
      SYS "GetDateFormat", 0, 0, S%, "ddd, dd MMM yyyy ", D%, 18
      SYS "GetTimeFormat", 0, 0, S%, "HH:mm:ss +0000", D%+17, 15
      D%?31 = 13

      PROC_initsockets
      skt% = FN_tcpconnect(smtp$,"mail")
      IF skt% <= 0 skt% = FN_tcpconnect(smtp$,"25")
      IF skt% <= 0 ERROR 100, "Failed to connect to mail server"
      IF FN_readlinesocket(skt%, 1000, reply$)
      WHILE FN_readlinesocket(skt%, 10, reply$) > 0 : ENDWHILE

      PROCsend(skt%,"HELO "+FN_gethostname)
      PROCmail(skt%,"MAIL FROM: ",from$)
      IF rcpt$<>"" PROClist(skt%,rcpt$)
      IF cc$<>"" PROClist(skt%,cc$)
      IF bcc$<>"" PROClist(skt%,bcc$)
      PROCsend(skt%, "DATA")

      IF FN_writelinesocket(skt%, "Date: "+$D%)
      IF FN_writelinesocket(skt%, "From: "+from$)
      IF FN_writelinesocket(skt%, "To: "+rcpt$)
      IF cc$<>"" IF FN_writelinesocket(skt%, "Cc: "+cc$)
      IF subject$<>"" IF FN_writelinesocket(skt%, "Subject: "+subject$)
      IF replyto$<>"" IF FN_writelinesocket(skt%, "Reply-To: "+replyto$)
      IF FN_writelinesocket(skt%, "MIME-Version: 1.0")
      IF attach$="" THEN
        IF FN_writelinesocket(skt%, "Content-Type: text/plain; charset=US-ASCII")
      ELSE
        IF FN_writelinesocket(skt%, "Content-Type: multipart/mixed; boundary=""BB4Wsep""")
        IF FN_writelinesocket(skt%, "")
        IF FN_writelinesocket(skt%, "--BB4Wsep")
        IF FN_writelinesocket(skt%, "Content-Type: text/plain")
        IF FN_writelinesocket(skt%, "Content-Transfer-Encoding: 7bit")
      ENDIF

      IF FN_writelinesocket(skt%, "")
      IF FN_writelinesocket(skt%, body$)
      IF attach$<>"" THEN
        REPEAT
          WHILE ASCattach$=32 attach$ = MID$(attach$,2) : ENDWHILE
          IF ASCattach$=34 THEN
            file$ = EVAL(attach$)
            comma% = INSTR(attach$, ",", LENfile$)
          ELSE
            comma% = INSTR(attach$, ",")
            IF comma% file$ = LEFT$(attach$, comma%-1) ELSE file$ = attach$
          ENDIF
          PROCattach(skt%, file$)
          attach$ = MID$(attach$, comma%+1)
        UNTIL comma%=0
        IF FN_writelinesocket(skt%, "--BB4Wsep--")
      ENDIF
      IF FN_writelinesocket(skt%, ".")

      PROCsend(skt%,"QUIT")

      PROC_exitsockets
      ENDPROC

      DEF PROClist(skt%,list$)
      LOCAL comma%
      REPEAT
        WHILE ASClist$=32 list$=MID$(list$,2):ENDWHILE
        comma% = INSTR(list$,",")
        IF comma% THEN
          PROCmail(skt%,"RCPT TO: ",LEFT$(list$,comma%-1))
          list$ = MID$(list$,comma%+1)
        ELSE
          PROCmail(skt%,"RCPT TO: ",list$)
        ENDIF
      UNTIL comma% = 0
      ENDPROC

      DEF PROCmail(skt%,cmd$,mail$)
      LOCAL I%,J%
      I% = INSTR(mail$,"<")
      J% = INSTR(mail$,">",I%)
      IF I% IF J% THEN
        PROCsend(skt%, cmd$+MID$(mail$,I%,J%-I%+1))
      ELSE
        PROCsend(skt%, cmd$+"<"+mail$+">")
      ENDIF
      ENDPROC

      DEF PROCsend(skt%,cmd$)
      LOCAL reply$
      IF FN_writelinesocket(skt%,cmd$) < 0 THEN
        ERROR 100, "Send failed"
      ENDIF
      IF FN_readlinesocket(skt%, 200, reply$)
      WHILE FN_readlinesocket(skt%, 10, reply$) > 0 : ENDWHILE
      ENDPROC

      DEF PROCattach(skt%,file$)
      LOCAL D%, F%, I%, L%, N%, A$, B$
      B$ = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
      F% = OPENIN(file$)
      IF F%=0 ERROR 100, "Failed to open attached file " + file$
      REPEAT
        D% = INSTR(file$, "\")
        IF D%=0 D% = INSTR(file$, "/")
        IF D% file$ = MID$(file$, D%+1)
      UNTIL D%=0
      IF FN_writelinesocket(skt%, "")
      IF FN_writelinesocket(skt%, "--BB4Wsep")
      IF FN_writelinesocket(skt%, "Content-Type: application/octet-stream")
      IF FN_writelinesocket(skt%, "Content-Disposition: attachment; filename="+file$)
      IF FN_writelinesocket(skt%, "Content-Transfer-Encoding: base64")
      IF FN_writelinesocket(skt%, "")
      L% = EXT#F%
      WHILE NOT EOF#F%
        N% = L% - PTR#F%
        D% = BGET#F% << 16 OR BGET#F% << 8 OR BGET#F%
        FOR I% = 1 TO 4 : A$ += MID$(B$,(D% >>> 18)+1,1) : D% = D% << 6 AND &FFFFFF : NEXT
        IF N%=1 RIGHT$(A$,2) = "==" ELSE IF N%=2 RIGHT$(A$) = "="
        IF LENA$>=72 IF FN_writelinesocket(skt%,A$)=0 A$ = ""
      ENDWHILE
      IF A$<>"" IF FN_writelinesocket(skt%, A$)
      CLOSE #F%
      ENDPROC